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kenshireen
11-21-2009, 09:14 PM
I have played for 40 years and having watched Federer slo-motion videos saw that he kept his head down on the ball as close as humanly possible until it struck his racket.

Most of us have a tendency to follow the ball but not TRY to watch it hit the racquet head.
We tend to look up at where the ball is going as we strike it..

What I am going to say is very subtle and difficult to do because of the inclination to see where the ball is going after you strike it. But I have been doing the following lately and it has significantly increased my consistency.

I follow the ball as it strikes the opponents racket and as it is crossing the net and coming to either my BH or FH I take a snapshot of the court and decide where I am going to attempt to hit the ball (i.e. DTH, CC, Drop, etc.) Now here is the most important and difficult part (only difficult due to habit). I watch the ball hit my racket head and only after I strike it do I look up.. I agree that there is only a millisecond difference between this technique and the other way where you strike and look up almost simultaneously.

But for me I find that I hit the ball much more consistently and have fewer frame shots.
It also stops me from lifting up my shoulder when striking the ball which tends to keep the ball from flying deep.

Now, I am a 3.5 player so take that into consideration..

Ken

crash1929
11-21-2009, 09:19 PM
yeah this is a key concept. feels good right?!

Ripper014
11-21-2009, 09:36 PM
Hmm.... this is some new technique? What will they come up with next... getting hard to keep up with this new age tennis stuff.

;)

chess9
11-22-2009, 05:24 AM
This is always a good reminder. It's very easy to get lazy about hitting the ball. In warm ups, I'll frequently just be loosening my arm up and NOT tightening up my eyeballs as well. :) Loose eyes, loose shots.

Thanks, Ken.

-Robert

kenshireen
11-22-2009, 05:50 AM
Think about how many times you have struck the ball and saw the other side of the court simultaneously... This is very common.. Almost as if you have one eye on the ball and one eye on the court. Now if you can strike the ball by keeping "both" eyes on the ball you will not be seeing anything at all on the other side of the net.. That is the litmus test to determine that you are really "watching" the ball all the way.

I have taught this to others and it does make their ball striking more consistent.

Now you might ask.. what happens in doubles when you take the snapshot and then focus on the ball only...and somebody decides to poach...do you have enough time to alter your originally designed shot....and the answer is usually yes.... because your snapshot is taken an instant before you strike the ball.

How many times have you heard someone say... I took my eyes off the ball and was looking at you move...etc.

This tehcnique, thought simplistic, and not new age, will improve the average club player if he sticks to it...

Ken

5263
11-22-2009, 08:26 AM
I have taught this to others and it does make their ball striking more consistent.

How many times have you heard someone say... I took my eyes off the ball and was looking at you move...etc.

This tehcnique, thought simplistic, and not new age, will improve the average club player if he sticks to it...

Ken

I think he was being facetious about the new age thing. There have been several threads on this and most likely you will be hearing from SA shortly about the science of seeing the ball as it approaches you.

However, none of this should take away from the grand experience you have now had of doing this and understanding the importance 1st hand, regardless of the science behind it. You will also have some interesting additions with this new understanding as you work with it.
Congrats on this breakthru!

Frank Silbermann
11-22-2009, 09:03 AM
Incompetent coaches have always told their pupils to watch the ball. Only the very best could teach their pupils _how_ to watch the ball. It can only be done by keeping the head still while tracking the ball with the eyes only -- most coaches don't bother to tell you that. Also, most people point their face towards the oncoming ball, so to track it as it hits the racket you have to have your eyes turned in their eye sockets as far as they'll go. What Federer seems to do is to point his face more to the side and start watching the incoming ball with his eyes turned as far as possible to the _other_ side, so that as the ball hits his racket his eyes are pointed pretty straight ahead.

That makes it easier to see the ball as it hits the racket, but it's hard to make yourself turn your face away from the ball as it's crossing the net.

kenshireen
11-22-2009, 09:17 AM
Incompetent coaches have always told their pupils to watch the ball. Only the very best could teach their pupils _how_ to watch the ball. It can only be done by keeping the head still while tracking the ball with the eyes only -- most coaches don't bother to tell you that. Also, most people point their face towards the oncoming ball, so to track it as it hits the racket you have to have your eyes turned in their eye sockets as far as they'll go. What Federer seems to do is to point his face more to the side and start watching the incoming ball with his eyes turned as far as possible to the _other_ side, so that as the ball hits his racket his eyes are pointed pretty straight ahead.

That makes it easier to see the ball as it hits the racket, but it's hard to make yourself turn your face away from the ball as it's crossing the net.

Frank,
Can you clarify what you mean when you say his eyes are pointed straight ahead.
You do mena they are pointed directed at the racket head.. correct?

I agree that keeping the head still is critical.. Have you ever noticed that when he lift your head up it tends to pull your arm/shoulder up with it... This again is subtle but have somebody video tape you and in slo-mo see what happens when you turn your head from the side to straightforward... (This is a 90 degree turn in effect)

LeeD
11-22-2009, 10:55 AM
Track the ball until your head NEEDS to move, then hold the head still.
You don't need to watch the ball INTO your racket. You only need to track it down to between 3-6' from your strikepoint.
Never ever look up before contact. You KNOW where the ball is going because YOU hit it ... :shock::shock:

Fedace
11-22-2009, 11:04 AM
I have played for 40 years and having watched Federer slo-motion videos saw that he kept his head down on the ball as close as humanly possible until it struck his racket.

Most of us have a tendency to follow the ball but not TRY to watch it hit the racquet head.
We tend to look up at where the ball is going as we strike it..

What I am going to say is very subtle and difficult to do because of the inclination to see where the ball is going after you strike it. But I have been doing the following lately and it has significantly increased my consistency.

I follow the ball as it strikes the opponents racket and as it is crossing the net and coming to either my BH or FH I take a snapshot of the court and decide where I am going to attempt to hit the ball (i.e. DTH, CC, Drop, etc.) Now here is the most important and difficult part (only difficult due to habit). I watch the ball hit my racket head and only after I strike it do I look up.. I agree that there is only a millisecond difference between this technique and the other way where you strike and look up almost simultaneously.

But for me I find that I hit the ball much more consistently and have fewer frame shots.
It also stops me from lifting up my shoulder when striking the ball which tends to keep the ball from flying deep.

Now, I am a 3.5 player so take that into consideration..

Ken


Slow mo videos show that it is impossible to actually see the ball strike your racket strings... it happens too fast..

LeeD
11-22-2009, 11:07 AM
Fed has some vids where it tracks right into impact.
You CAN track into impact if you hit really in front of you, early and solid. You cannot track into impact on EVERY incoming shot, as some get behind you, some to the side, some you happen to be taking a hard step.
3-6' without LIFTING your eyes is good enough.

SystemicAnomaly
11-22-2009, 01:00 PM
Fed has some vids where it tracks right into impact.
You CAN track into impact if you hit really in front of you, early and solid...
3-6' without LIFTING your eyes is good enough.

Fed does not actually track the ball all the way into impact. If you look more closely at the very high speed footage, you may notice that his eyes actually get to the impact/contact point slightly before the ball does.

As Fedace indicates, our eyes are incapable of tracking the ball all the way into the strings. I've talked about the science of the way our eyes actually see and track moving objects numerous times before, so I'm not going to get into it here. Suffice it to say the the ball essentially becomes invisible (to the player attempting to hit the ball) about a meter or 2 before it gets to the impact point on most incoming balls. By keeping the head & eyes still, we can sometimes pick up a momentary yellow blur sometime after our eyes can no longer track it using the smooth pursuit system.

Whether we see the blur or not, may or may not be important. The most important part of this process is to keep the head still and the eyes "quiet". I prefer to say that Federer fixates on the impact point rather than on the ball.

Note also the the head & eyes should remain quiet for than just a millisecond after contact. That would be way too quick. It is more like hundreds of milliseconds. Consider that the the ball is on the strings for something like 4-5 milliseconds. This time duration represents a very small portion of the forward swing of the racquet. The head/eye should stay still longer than most people think. Note in the pix below that Federer still has his eyes fixated on the impact point well after contact -- his head does not move until he is nearly finished with the follow-thru.

http://www.tennis4everyone.com/images/stories/tips/FEDSEQ/6480.jpg
http://www.tennis.com/uploadedImages/Your_Game/Instruction_Articles/Forehand/2007_06_11_federer_forehand_4.jpg

.

kenshireen
11-22-2009, 02:53 PM
Track the ball until your head NEEDS to move, then hold the head still.
You don't need to watch the ball INTO your racket. You only need to track it down to between 3-6' from your strikepoint.
Never ever look up before contact. You KNOW where the ball is going because YOU hit it ... :shock::shock:

Exactly, you know where it is going before you hit it.. You must have the confidence in your strokes to know this. The only caveat is when playing doubles you might see a shot and then there is a last second poachfrom your opponent which may leave an alley open.. I think there is a chance you may miss this opportunity

kenshireen
11-22-2009, 02:57 PM
Slow mo videos show that it is impossible to actually see the ball strike your racket strings... it happens too fast..

I disagree... maybe at the pro level where they are hitting 100 fh..but you take a recreational, mid level player and you can see the ball strike the strings... I have done it myself on many occassions and I don't push the ball. I would like some of you guys to try this next time out and give me some feedback... I'm not referring to 4.5 and above but rather 3.0-4.0

Ken

kenshireen
11-22-2009, 03:05 PM
As Fedace indicates, our eyes are incapable of tracking the ball all the way into the strings. I've talked about the science of the way our eyes actually see and track moving objects numerous times before, so I'm not going to get into it here. Suffice it to say the the ball essentially becomes invisible (to the player attempting to hit the ball) about a meter or 2 before it gets to the impact point on most incoming balls. By keeping the head & eyes still, we can sometimes pick up a momentary yellow blur sometime after our eyes can no longer track it using the smooth pursuit system.

I still do not agree that you cannot see the ball hit the strings. You see the ball coming towards you and then you make the turn to either FH or BH-and move the racket forward (in frontof your body) and keep your head on that ball until it hits the racket....I have done this many times. I don't see why it is occularly impossible to see the actual impact.

Once again mid level players...tempo and racket head speed

teppeiahn1
11-22-2009, 03:06 PM
not about watchign the ball hit the strings, its more about making sure your hitting out in front of you cleanly.

kenshireen
11-22-2009, 03:08 PM
not about watchign the ball hit the strings, its more about making sure your hitting out in front of you cleanly.


To hit cleanly you must keep your eyes and head on the ball.. Hitting out in front is more the biomechaincs of good footwork

Clintspin
11-22-2009, 03:49 PM
What Federer does has nothing to do with watching the ball. It is about keeping your head still so that your shoulders and other body parts don't move. A golfer can clearly see the ball before he/she swings, the golf ball is not moving but that golfer must keep the head still to keep from pulling away from the ball and thus slicing or hooking.

And yes it has been proved over and over that you can no more watch the tennis ball hit your stings than a baseball player can watch the ball hit the bat. I would go further and say trying to watch the ball hit the strings will mess your shot up.

Bungalo Bill
11-22-2009, 04:08 PM
I have played for 40 years and having watched Federer slo-motion videos saw that he kept his head down on the ball as close as humanly possible until it struck his racket.

Most of us have a tendency to follow the ball but not TRY to watch it hit the racquet head.
We tend to look up at where the ball is going as we strike it..

What I am going to say is very subtle and difficult to do because of the inclination to see where the ball is going after you strike it. But I have been doing the following lately and it has significantly increased my consistency.

I follow the ball as it strikes the opponents racket and as it is crossing the net and coming to either my BH or FH I take a snapshot of the court and decide where I am going to attempt to hit the ball (i.e. DTH, CC, Drop, etc.) Now here is the most important and difficult part (only difficult due to habit). I watch the ball hit my racket head and only after I strike it do I look up.. I agree that there is only a millisecond difference between this technique and the other way where you strike and look up almost simultaneously.

But for me I find that I hit the ball much more consistently and have fewer frame shots.
It also stops me from lifting up my shoulder when striking the ball which tends to keep the ball from flying deep.

Now, I am a 3.5 player so take that into consideration..

Ken

Even in the other way of doing it you should not look up. Regardless of which technique you use, keeping your head still at contact is important. Also, since the eyes are legally blind when the ball is about 4 - 5 feet from contact, it will look like the eyes are glazed and unable to track the ball any more. It will look like the eyes are looking away from contact when it is simply that the blur of the ball is what it sees.

If you want to turn your head towards impact that is fine but you should keep your head still on both techniques.

user92626
11-22-2009, 04:13 PM
To me it's very simple, you do watch the ball and keep the upperbody still as you hit. Those who say you do not see the ball, what about very slow ball, 10 mph or so? Your eyes suddenly turn blind? If you can see a 10mph ball clearly it stands to reason that you certainly can see 20 mph, but with less accuracy. And that's the thing, the higher pace the ball has, the less accuracy you can watch it as you hit. So, the bottomline is you just try and watch it your best, and try to have the best probability of hitting it accurately.

nabrug
11-22-2009, 04:48 PM
Saccade/Eye-jump?

ShooterMcMarco
11-22-2009, 04:55 PM
I'm the worst offender of snapping my head in the direction of the ball prior to making contact. Bad, very bad.

papa
11-22-2009, 05:41 PM
Well, keep in mind that our brains, only see something like 20 -30 frames per second - kinda like a motion picture reel. Although we think we see a continuous picture, the fact is we don't. That's why is so important to watch the ball into the racquet, even on the serve - you need that "latest/last" frame to provide you brain with the most accurate information.

kenshireen
11-22-2009, 06:41 PM
I'm going out to use my ball machine tomorrow and I will set it at non-oscillating, medium ball speed and medium control. The balls should more or less come to the same spot. I will report back if I was actually able to see the ball impact the string. I have 20/20 vision and also perfect near term vision.

ShooterMcMarco
11-22-2009, 06:46 PM
Well, keep in mind that our brains, only see something like 20 -30 frames per second - kinda like a motion picture reel. Although we think we see a continuous picture, the fact is we don't. That's why is so important to watch the ball into the racquet, even on the serve - you need that "latest/last" frame to provide you brain with the most accurate information.

The master in action:

http://www.youtube.com/watch?v=HnB3Jxy9Ecc

jswinf
11-22-2009, 07:21 PM
I regurlaly "remember" to watch the ball as closely as possible and am surprised how much better/more consistent the results are, still after not too long it's faded from the top of the list. I bet lots of people have similar experiences.

Attempting to watch the ball to contact, regardless of physiological limits on human ability to do that, will help your eye-hand coordination get the racket in the best place to impact the ball. Just like the importance of a follow-through, what the racket does after the ball leaves the strings obviously doesn't affect the shot, but if the stroke was correct a certain follow-through must result.

I'm all for watching the ball (when I remember to.)

spacediver
11-22-2009, 10:20 PM
It may be useful to conceptualize this issue in terms of feedforward and feedback.

Feedforward can be thought of responses that are pre-programmed, while feedback can be thought of responses to real-time information.

Due to our limitations in visually processing information and generating motor outputs, there will necessarily be a portion of our response that is feedforward.

The key is to optimize the flow of visual information so that our brains have as much information as possible to reliably predict the course of events that we cannot see, and then to optimize our biomechanics such that the feedforward execution is as smooth as possible.

Keeping the head still may facilitate this latter stage.

crash1929
11-22-2009, 10:51 PM
this is a basic idea yet i constantly have to remind myself to do it. and i'm 4.5. i never even heard of this concept until i started on this site a number of years ago. i notice feds baby pic hitting a fh and he is already keeping his head still and not moving it, even at like 3.

i mostly pick my head up when i'm running and stretching out to hit a fh. i can't help looking up to see where the ball is going.

i also pull my head down on my serve way too much.

jmjmkim
11-22-2009, 11:47 PM
This applies to GOLF as well.

SystemicAnomaly
11-23-2009, 05:21 AM
I disagree... maybe at the pro level where they are hitting 100 fh..but you take a recreational, mid level player and you can see the ball strike the strings... I have done it myself on many occassions and I don't push the ball. I would like some of you guys to try this next time out and give me some feedback... I'm not referring to 4.5 and above but rather 3.0-4.0

I still do not agree that you cannot see the ball hit the strings. You see the ball coming towards you and then you make the turn to either FH or BH-and move the racket forward (in frontof your body) and keep your head on that ball until it hits the racket....I have done this many times. I don't see why it is occularly impossible to see the actual impact.

Once again mid level players...tempo and racket head speed

Nope, not buying it. I don't believe that you are actually seeing what you think you are seeing. Your brain is undoubtedly filling in a lot more gaps than you realize.

Let's look at the pro level first for the sake of comparison. A 130 mph serve will be traveling at about 60 mph by the time that it gets to the opposite baseline. The pros are probably hitting most groundstrokes for shots with an incoming speeds of 30-60 mph. A pro at the net could easily face incoming shots that are in excess of 75 mph. At these speeds, the ball essentially becomes "invisible" more than 4 meters before it reaches the volleyer. According to an expert on an episode of Sport Science, a baseball batter facing a 90 mph pitch is incapable of seeing/tracking the ball for the last 15 feet before it reaches the plate.

I would estimate that 3.0/3.5 players are routinely facing balls that are in the range of 20-40 mph. Even very slow balls in the 15-25 mph range can exceed the eyes ability to see & track the ball once it gets within 2-3 feet. There may be a very low % of shots that are actually slow enough for our eyes to track clearly/cleanly (without saccadic jumps).

It is not just the speed of the ball, but its proximity to the player that makes it impossible to track it. Our smooth pursuit system can successfully track balls that traverse our field of central (foveal) vision at speed less than 30 degrees/sec (3 degrees per 100 ms). According the the following source, the peak velocity for the smooth pursuit system is in the range of 20-50 degrees/sec.

Smooth pursuit eye movements (http://www.websciences.org/cftemplate/NAPS/archives/indiv.cfm?ID=19979773)

For events that exceed the smooth pursuit system, the eyes/brain employ a movement know as a jump-ahead saccade. The eyes jump ahead in an effort to catch up or "lie in wait" for a moving object that it can no track with smooth pursuit movements. The saccadic system may be useful at peak velocities up 700-900 degrees/sec (70-90 degrees per 100 ms). We do not actually see the ball when the eyes are (saccadic) jumping. The brain will sometimes try to fill in the missing visual information. We can often pick a momentary blur of the ball near or at impact. Since the ball changes directing during impact, it does have a velocity of zero for an instant (something on the order of a millisecond). It is possible that one might pick up a very brief image of the ball at/near impact.
.

papa
11-23-2009, 05:24 AM
I'm going out to use my ball machine tomorrow and I will set it at non-oscillating, medium ball speed and medium control. The balls should more or less come to the same spot. I will report back if I was actually able to see the ball impact the string. I have 20/20 vision and also perfect near term vision.

Well, the ball is on the racquet for such a small fraction of time that its difficult/impossible to see it at impact. Vision is one thing, frames that you see is another --- you would have to see in the order of 150 - 200 frames per second to see this on a regular basic - I think thats far out of the possible/probable range.

Should you watch the ball into the racquet - absolutely.

SystemicAnomaly
11-23-2009, 05:27 AM
< This post intentionally left blank >




.

papa
11-23-2009, 05:28 AM
I regurlaly "remember" to watch the ball as closely as possible and am surprised how much better/more consistent the results are, still after not too long it's faded from the top of the list. I bet lots of people have similar experiences.

Attempting to watch the ball to contact, regardless of physiological limits on human ability to do that, will help your eye-hand coordination get the racket in the best place to impact the ball. Just like the importance of a follow-through, what the racket does after the ball leaves the strings obviously doesn't affect the shot, but if the stroke was correct a certain follow-through must result.

I'm all for watching the ball (when I remember to.)

Yes, good post.

papa
11-23-2009, 05:39 AM
a baseball batter facing a 90 mph pitch is incapable of see/tracking the ball for the last 15 feet before it reaches the plate.

.

I have heard this several times but not seen the actual quote. One thing we as tennis players have over baseball players is that regardless of where the ball is going we have to hit it. We also have a much larger hitting surface to work with and getting hit is not much of a factor. I would think the baseball player has to make up his mind about swinging maybe when the ball is still fifteen feet away but that maybe he will get another frame or two as he's swinging.

Not a baseball player but I find this interesting.

SystemicAnomaly
11-23-2009, 05:39 AM
... I have 20/20 vision and also perfect near term vision.

These are measures of static visual acuity. It says very little of our ability to perform smooth pursuit tracking or saccadic tracking of a dynamic (moving) object.

(refer to post #30 above)

SystemicAnomaly
11-23-2009, 05:58 AM
I have heard this several times but not seen the actual quote. One thing we as tennis players have over baseball players is that regardless of where the ball is going we have to hit it. We also have a much larger hitting surface to work with and getting hit is not much of a factor. I would think the baseball player has to make up his mind about swinging maybe when the ball is still fifteen feet away but that maybe he will get another frame or two as he's swinging.

Not a baseball player but I find this interesting.

Yes, the batter does need to make up his mind early if he decides to swing because it takes some time to move the bat into position to contact the ball. For a 90 mph pitch, the ball takes about 400 ms to reach the plate once if leaves the pitcher's hand. However, because of the time it takes to swing the bat, the batter probably has less much less than 200 ms to react. The best batters in bb probably have simple visual reaction times of 150 ms or better (compared to 200-250 ms for the general population).

Baseball batter are taught to keep the head down/still and eyes on the expected impact point if they decide to swing at a pitch. (This is very much like the technique the Federer uses when hitting a tennis ball). Even tho' the bb batter has lost sight of the ball 15 feet before it has reached the plate, it is possible the saccadic system may pick up some additional visual info just prior to contact. (I can try to dig up a link for that Sport Science episode if you are interested).

http://www.powerbatting.com/images/001_1.JPG
http://majorleaguejerk.files.wordpress.com/2008/06/hitting-a-baseball.jpg

LeeD
11-23-2009, 07:58 AM
Batters and golfers have feet set every time, stance set before incoming ball even starts.
Tennis players occasionally set their feet, make up some by jumping, but also hit lots of balls with the torso moving, the feet moving, or even turning during the shot, so harder to track the ball. Tennis balls can come high or slow, spun differently, arc differently, and in or out.
But you TRY to track it all the way in. You don't at times, you do quite often. That's the best you can do.

Power Player
11-23-2009, 08:32 AM
If I keep my head down and eyes on the ball, move my feet and hit out in front... good things happen the majority of the time.

5263
11-23-2009, 11:20 AM
If I keep my head down and eyes on the ball, move my feet and hit out in front... good things happen the majority of the time.

Yep, and the scientific terms to describe what's happening haven't changed any of that yet.

papa
11-23-2009, 12:04 PM
(I can try to dig up a link for that Sport Science episode if you are interested).



Well, I'd be interested if its fairly easy to locate. Not sure I'll be able to comprehend the whole thing but it certainly sounds interesting.

SystemicAnomaly
11-23-2009, 02:10 PM
If I keep my head down and eyes on the ball, move my feet and hit out in front... good things happen the majority of the time.

Yep, and the scientific terms to describe what's happening haven't changed any of that yet.

Actually, it has. When the ball is in close proximity, it is not "eyes on the ball", it is "eyes on the contact point". This is an important difference in my mind. It is one of the basic tenets of the "Quiet Eye (http://edition.cnn.com/2005/TECH/03/21/spark.quiet.eye/index.html)" technique (in the field of gaze control) developed by expert, Joan Vickers (http://www.pbs.org/saf/1206/segments/1206-1.htm).

In Federer's case. his gaze is fixed on the impact zone on the incoming ball as well as for the outgoing ball. (He appears to fix his gaze a bit longer on the contact zone when the ball is outgoing than he does when the ball is approaching the contact area).

SystemicAnomaly
11-23-2009, 02:23 PM
A number of people felt that I summed it up best in the following post (In fact, someone even quoted the whole post on TennisPlayer.net)

http://tt.tennis-warehouse.com/showthread.php?p=3717482 (http://tt.tennis-warehouse.com/showthread.php?p=3717482)

.

SystemicAnomaly
11-23-2009, 02:47 PM
... (I can try to dig up a link for that Sport Science episode if you are interested)...

Well, I'd be interested if its fairly easy to locate. Not sure I'll be able to comprehend the whole thing but it certainly sounds interesting.

Actually, the Sport Science episode does not really get into all the dirty, nasty details. It should be fairly easy to comprehend. I provide the Sport Science link in the following posts:

http://tt.tennis-warehouse.com/showthread.php?p=2409847 (http://tt.tennis-warehouse.com/showthread.php?p=2409847&highlight=Sport+Science+saccadic#post2409847)

http://tt.tennis-warehouse.com/showthread.php?p=3413660 (http://tt.tennis-warehouse.com/showthread.php?p=3413660&highlight=Sport+Science+saccadic#post3413660)
.

5263
11-23-2009, 03:29 PM
Actually, it has. When the ball is in close proximity, it is not "eyes on the ball", it is "eyes on the contact point". This is an important difference in my mind. It is one of the basic tenets of the "Quiet Eye (http://edition.cnn.com/2005/TECH/03/21/spark.quiet.eye/index.html)" technique (in the field of gaze control) developed by expert, Joan Vickers (http://www.pbs.org/saf/1206/segments/1206-1.htm).

In Federer's case. his gaze is fixed on the impact zone on the incoming ball as well as for the outgoing ball. (He appears to fix his gaze a bit longer on the contact zone when the ball is outgoing than he does when the ball is approaching the contact area).

I can't really agree, but that is fine. Many of us have been doing this for decades before hearing this explanation, by just using the eye on the ball coaching. It's great though if this description helps more people to learn to use this technique that comes natural to many athletes and maybe just about anybody. It is the normal way of seeing, first smooth tracking, then jumping ahead to a spot when the closure is too fast. It seems that some just choose a different spot to jump ahead to.

Here is some discussion as it relates to Federer and it describes the method as I have used it-

http://www.revolutionarytennis.com/federervisiontechnique.html#rebuttalvision

quote-Federer doesn't look for the contact in front of the racket, he looks for it from the back of the racket as the photos indicate. The back of the racket lies between his eyes and ball contact, his visual focus for contact goes to the back the racket and not the front as everyone else does. Though at times the ball may be visible during contact through the string bed from behind if the ball's high enough it's really looking from the back of the racket that primes this technique and not a desire to actually see the ball hit the strings. Federer is not trying to see the ball hit the strings, he is in fact seeing the racket hit the ball, specifically seeing the back of the racket flashing through.

papa
11-23-2009, 06:05 PM
Actually, the Sport Science episode does not really get into all the dirty, nasty details. It should be fairly easy to comprehend. I provide the Sport Science link in the following posts:

http://tt.tennis-warehouse.com/showthread.php?p=2409847 (http://tt.tennis-warehouse.com/showthread.php?p=2409847&highlight=Sport+Science+saccadic#post2409847)

http://tt.tennis-warehouse.com/showthread.php?p=3413660 (http://tt.tennis-warehouse.com/showthread.php?p=3413660&highlight=Sport+Science+saccadic#post3413660)
.

Very interesting stuff. Have you gotten into this as a separate profession or just from your interest in tennis?

SystemicAnomaly
11-25-2009, 02:08 AM
I can't really agree, but that is fine. Many of us have been doing this for decades before hearing this explanation, by just using the eye on the ball coaching. It's great though if this description helps more people to learn to use this technique that comes natural to many athletes and maybe just about anybody. It is the normal way of seeing, first smooth tracking, then jumping ahead to a spot when the closure is too fast. It seems that some just choose a different spot to jump ahead to...

I've been doing this for decades as well but have refined my teaching regarding "watching the ball" in recent years. Most, but not all, students of tennis do not really need to be told to "watch the ball". That should pretty much be intuitive for most players. However, what is not really intuitive is that the eyes and head should be kept still for a while -- just prior to impact, during contact, and for a while after contact. This is pretty much counter-intuitive.

When players are told to watch the ball at all times, they will often move the eyes & head too much in an effort to follow the ball all the way into the strings and then try to follow the ball immediately after contact. Many others will pull their eyes & head up just before contact in a misguided effort to look at the target area. The eyes/head probably come up when they can no longer track the incoming ball with the smooth pursuit system. In either case, mis-hits will often result because the swing path is altered when the head moves prematurely.

slepax
11-25-2009, 05:04 AM
Actually, it has. When the ball is in close proximity, it is not "eyes on the ball", it is "eyes on the contact point". This is an important difference in my mind.

In Federer's case. his gaze is fixed on the impact zone on the incoming ball as well as for the outgoing ball. (He appears to fix his gaze a bit longer on the contact zone when the ball is outgoing than he does when the ball is approaching the contact area).

I am a very systematic myself so I want to make sure I understand what you are saying:

1. Your opponent hits the balls towards your side of the court.
2. You watch the ball up to several feet from where you stand, where at this point it becomes impossible to actually track the ball any further.
3. Your head/eyes then jumps to the estimated contact point, while the ball is still travelling and your racquet is still travelling to the contact point.
4. You then hit the ball while keeping your head still until sometimes after contact.

That sounds extremely hard, something that requires a superb hands-eye coordination...

SystemicAnomaly
11-25-2009, 05:25 AM
^ Yes, tennis is a bit of a challenge. This is also pretty much the same sequence a baseball batter or cricket batsman goes thru to hit a ball. With tennis pros, you do see some variations for #3. I believe that Agassi stopped moving his head & eyes at a approx the point where the ball vanishes rather than at the expected contact point. Many players will look at a point just in front of the racquet's expected impact point whereas Federer "appears" to be looking thru his strings to "see" the incoming ball.

5263
11-25-2009, 05:52 AM
I've been doing this for decades as well but have refined my teaching regarding "watching the ball" in recent years. Most, but not all, students of tennis do not really need to be told to "watch the ball". That should pretty much be intuitive for most players. However, what is not really intuitive is that the eyes and head should be kept still for a while -- just prior to impact, during contact, and for a while after contact. This is pretty much counter-intuitive.

When players are told to watch the ball at all times, they will often move the eyes & head too much in an effort to follow the ball all the way into the strings and then try to follow the ball immediately after contact. Many others will pull their eyes & head up just before contact in a misguided effort to look at the target area. The eyes/head probably come up when they can no longer track the incoming ball with the smooth pursuit system. In either case, mis-hits will often result because the swing path is altered when the head moves prematurely.

I can't agree that student don't have to be reminded of watching the ball, but do completely with what you say about keeping the head still, except that watching the ball would be counter to keeping the head still. I teach this in a way that the concepts work together. I've been teaching it this way since '93 and how nice it was when Fed came along as a super model for me to refer to.

papa
11-25-2009, 06:03 AM
I can't agree that student don't have to be reminded of watching the ball ..........

Yeah, me too. Probably means that they "know to watch the ball" but its amazing the shortcut that constantly creep into the picture.
Actually, we're all guilty of it from time to time. My mind, whats left of it anyway, has a tendency to wander.

Good stuff though.

slepax
11-25-2009, 06:58 AM
^ Yes, tennis is a bit of a challenge. This is also pretty much the same sequence a baseball batter or cricket batsman goes thru to hit a ball. With tennis pros, you do see some variations for #3. I believe that Agassi stopped moving his head & eyes at a approx the point where the ball vanishes rather than at the expected contact point. Many players will look at a point just in front of the racquet's expected impact point whereas Federer "appears" to be looking thru his strings to "see" the incoming ball.

It does make sense though.

One thing I learned from motorcycle racing is that the bike goes where you look (obviously because it is you who drive it there), I think this would be the same for the tennis. Once you develop the skills of fixating your eyes on the contact point, the racquet will "drive" itself to the contact point automatically, merely because this is one of the inherent attributes we have as humans.

jswinf
11-25-2009, 11:45 AM
It occurs to me that "smooth pursuit" eye movements might not be quite the limiting factor some posts assume, since the ball is approaching more or less toward the receiver, who is moving toward it and moving their head to look at it, so the eyes often remain in a "primary gaze" position, straight ahead relative to head position. It seems reasonable to follow the ball as much as possible by moving the head, like the good baseball hitters.

I hadn't seen that stuff about Federer tilting his head and looking at the back of the racket before. It's intriguing, I don't suppose he does it just because it looks cool...I'll have to try it, hope I don't hurt myself.

SystemicAnomaly
11-25-2009, 01:39 PM
...

Here is some discussion as it relates to Federer and it describes the method as I have used it-

http://www.revolutionarytennis.com/federervisiontechnique.html#rebuttalvision

quote-Federer doesn't look for the contact in front of the racket, he looks for it from the back of the racket as the photos indicate. The back of the racket lies between his eyes and ball contact, his visual focus for contact goes to the back the racket and not the front as everyone else does. Though at times the ball may be visible during contact through the string bed from behind if the ball's high enough it's really looking from the back of the racket that primes this technique and not a desire to actually see the ball hit the strings. Federer is not trying to see the ball hit the strings, he is in fact seeing the racket hit the ball, specifically seeing the back of the racket flashing through.

It is interesting to note that Mark Papas also talks about jump saccades in his Rev Tennis article on the Fed vision technique (guess I'm not the only one). He does get a bit into the science of tennis. He has some excellent insights on tennis technique altho' I don't agree with everything that he has to say -- such as his take on "wrist snap" and his insistence that Federer uses a variety of Western grips (in the vision article).


I can't agree that student don't have to be reminded of watching the ball, but do completely with what you say about keeping the head still, except that watching the ball would be counter to keeping the head still. I teach this in a way that the concepts work together. I've been teaching it this way since '93 and how nice it was when Fed came along as a super model for me to refer to.

With the approach that I've adopted in the past few years, I find myself frequently or regularly reminding students to "keep the head still" or "eyes fixed on the contact" (during the forward swing). Only rarely do I ever need to remind students to "watch the ball". For most of my students, if I remind them to "keep the head still" or "quiet eyes" during the forward swing, "watching the ball" really seems to take care of itself for the most part.

LeeD
11-25-2009, 01:43 PM
What doesn't work....
Keep your eyes on the blonde cutie 5 rows up behind the net judge !!!

SystemicAnomaly
11-25-2009, 01:53 PM
It occurs to me that "smooth pursuit" eye movements might not be quite the limiting factor some posts assume, since the ball is approaching more or less toward the receiver, who is moving toward it and moving their head to look at it, so the eyes often remain in a "primary gaze" position, straight ahead relative to head position. It seems reasonable to follow the ball as much as possible by moving the head, like the good baseball hitters...

Yes, the whole ball tracking thing is even more complex that what I've presented. Elite baseball hitters & tennis players will often try to follow the incoming ball as much as possible moving the head (as needed). However, the head stops moving relative to the body when the forward swing commences (until the follow-thru is nearly complete in the case of Federer, Nadal & others).


...

I hadn't seen that stuff about Federer tilting his head and looking at the back of the racket before. It's intriguing, I don't suppose he does it just because it looks cool...I'll have to try it, hope I don't hurt myself.

In order to employ this technique, the ball contact should be made well in front. Many players that use a 1-handed (topspin) BH have also employed a similar technique since the contact point is usually well in front.

LeeD
11-25-2009, 02:25 PM
Yes, and meaning most players can only track the ball to the racket maybe 30% of the time. We don't all hit perfect 1hbh topspin backhands with full use of the kinetics, as the opposing player is trying to take up out of our comfort zone. If we manage to track the ball into the strings even that often, we're doing really good and often winning the match.
When the opponent makes us run full speeds, dig, retrieve, fetch, we're barely seeing the ball within 5' of the contact point.

Frank Silbermann
11-26-2009, 11:28 AM
I am a very systematic myself so I want to make sure I understand what you are saying:

1. Your opponent hits the balls towards your side of the court.
2. You watch the ball up to several feet from where you stand, where at this point it becomes impossible to actually track the ball any further.
3. Your head/eyes then jumps to the estimated contact point, while the ball is still travelling and your racquet is still travelling to the contact point.
4. You then hit the ball while keeping your head still until sometimes after contact.

That sounds extremely hard, something thatReally bad players track the ball with their heads rather than with their eyes, which destroys all hand-eye coordination. requires a superb hands-eye coordination... Really bad players track the ball with their heads rather than with their eyes, which destroys all hand-eye coordination. Most good players turn their head towards the ball early and track it with their eyes until a few feed before impact -- at which time the ball has passed out of view.

If Federer waited until the ball was out of his vision before turning his head towards the point of impact, then his head would still be moving when he hit the ball, and he would be a lousy player. Rather, he turns his head towards the point of impact long before the ball would have past his ability to track it with his eyes.

However, if his _eyes_ also were then turned towards the expected point of impact -- as #3 suggests, that would mean Federer stopped seeing the ball earlier than most good players, which is highly unlikely. In general, the longer you see the ball, the better.

That's why I suspect Federer turns his _head_ early to face the expected point of impact, but then turns his eyes towards the ball to track it into that point of impact as long as he can.

However, as the ball comes in, his eyes move from the side of his eye-sockets towards "straight ahead" -- therefore as the ball gets closer his vision improves! (It's easier to see something well if it's right in front of you than if you have to give it a sideways glance.)

Because his head is turned before the last dozen feed of the balls flight, he can track it further in than most players -- which would explain his superior hitting.

Anyway, I've yet to hear a more likely explanation

5263
11-26-2009, 05:07 PM
It is interesting to note that Mark Papas also talks about jump saccades in his Rev Tennis article on the Fed vision technique (guess I'm not the only one).

With the approach that I've adopted in the past few years, I find myself frequently or regularly reminding students to "keep the head still" or "eyes fixed on the contact" (during the forward swing). Only rarely do I ever need to remind students to "watch the ball". For most of my students, if I remind them to "keep the head still" or "quiet eyes" during the forward swing, "watching the ball" really seems to take care of itself for the most part.

Yes, but Papas also points out how this is how it is normally done, without special coaching. The coaching mainly deals with where you jump to, not that you jump ahead.

As for what you find yourself doing, that would be natural given your perspective on the subject, but that would not mean it is needed.

SystemicAnomaly
11-27-2009, 12:25 AM
< double post deleted >


.

ShooterMcMarco
11-27-2009, 12:31 PM
In order to employ this technique, the ball contact should be made well in front. Many players that use a 1-handed (topspin) BH have also employed a similar technique since the contact point is usually well in front.

Maybe this is why its hard for me to do on the forehand, I guess my forehand contact point is not as far in front as my one hander.

nabrug
11-27-2009, 01:16 PM
Incompetent coaches have always told their pupils to watch the ball. Only the very best could teach their pupils _how_ to watch the ball. It can only be done by keeping the head still while tracking the ball with the eyes only -- most coaches don't bother to tell you that. Also, most people point their face towards the oncoming ball, so to track it as it hits the racket you have to have your eyes turned in their eye sockets as far as they'll go. What Federer seems to do is to point his face more to the side and start watching the incoming ball with his eyes turned as far as possible to the _other_ side, so that as the ball hits his racket his eyes are pointed pretty straight ahead.

That makes it easier to see the ball as it hits the racket, but it's hard to make yourself turn your face away from the ball as it's crossing the net.

Incompetent coaches told their pupils to watch the ball. But do I get your message that you also tell them to watch the ball? Is the difference you tell them how to do it? Please for a research project I want to know more.

nabrug
11-27-2009, 01:26 PM
Fed does not actually track the ball all the way into impact. If you look more closely at the very high speed footage, you may notice that his eyes actually get to the impact/contact point slightly before the ball does.

As Fedace indicates, our eyes are incapable of tracking the ball all the way into the strings. I've talked about the science of the way our eyes actually see and track moving objects numerous times before, so I'm not going to get into it here. Suffice it to say the the ball essentially becomes invisible (to the player attempting to hit the ball) about a meter or 2 before it gets to the impact point on most incoming balls. By keeping the head & eyes still, we can sometimes pick up a momentary yellow blur sometime after our eyes can no longer track it using the smooth pursuit system.

Whether we see the blur or not, may or may not be important. The most important part of this process is to keep the head still and the eyes "quiet". I prefer to say that Federer fixates on the impact point rather than on the ball.

Note also the the head & eyes should remain quiet for than just a millisecond after contact. That would be way too quick. It is more like hundreds of milliseconds. Consider that the the ball is on the strings for something like 4-5 milliseconds. This time duration represents a very small portion of the forward swing of the racquet. The head/eye should stay still longer than most people think. Note in the pix below that Federer still has his eyes fixated on the impact point well after contact -- his head does not move until he is nearly finished with the follow-thru.

http://www.tennis4everyone.com/images/stories/tips/FEDSEQ/6480.jpg
http://www.tennis.com/uploadedImages/Your_Game/Instruction_Articles/Forehand/2007_06_11_federer_forehand_4.jpg

.


Is this your own analysis? What other sources did you use?

nabrug
11-27-2009, 01:30 PM
Well, keep in mind that our brains, only see something like 20 -30 frames per second - kinda like a motion picture reel. Although we think we see a continuous picture, the fact is we don't. That's why is so important to watch the ball into the racquet, even on the serve - you need that "latest/last" frame to provide you brain with the most accurate information.

But why is it so important to see the ball into the racket? Why do I need that last frame. If my brain fills in the open gaps. At a certain point you can trust the brain to fill in that point?!

nabrug
11-27-2009, 01:35 PM
I regurlaly "remember" to watch the ball as closely as possible and am surprised how much better/more consistent the results are, still after not too long it's faded from the top of the list. I bet lots of people have similar experiences.

Attempting to watch the ball to contact, regardless of physiological limits on human ability to do that, will help your eye-hand coordination get the racket in the best place to impact the ball. Just like the importance of a follow-through, what the racket does after the ball leaves the strings obviously doesn't affect the shot, but if the stroke was correct a certain follow-through must result.

I'm all for watching the ball (when I remember to.)

Very important for me right now is to know from you and others why you fail to watch the ball. I know the feeling. But if you say it, it sounds like it is one of the most important things we have to do.

nabrug
11-27-2009, 02:08 PM
It is interesting to note that Mark Papas also talks about jump saccades in his Rev Tennis article on the Fed vision technique (guess I'm not the only one). He does get a bit into the science of tennis. He has some excellent insights on tennis technique altho' I don't agree with everything that he has to say -- such as his take on "wrist snap" and his insistence that Federer uses a variety of Western grips (in the vision article).




With the approach that I've adopted in the past few years, I find myself frequently or regularly reminding students to "keep the head still" or "eyes fixed on the contact" (during the forward swing). Only rarely do I ever need to remind students to "watch the ball". For most of my students, if I remind them to "keep the head still" or "quiet eyes" during the forward swing, "watching the ball" really seems to take care of itself for the most part.

Do you just ask them to watch the ball? In a kind of abstract way? Or do you give information? This question is not about how you do it. You explained that. It is more about the watching!

papa
11-27-2009, 03:10 PM
Do you just ask them to watch the ball? In a kind of abstract way? Or do you give information? This question is not about how you do it. You explained that. It is more about the watching!

Well, I do. I actually go out of my way to get them to understand that our eyes capture snapshots at the rate of 20 - 30 per second and I'll actually place balls on the court so they can see, depending on the pace, what that actually looks like. I want them, as much as possible, to follow the ball into the racquet with their eyes mostly but some limited turning of the head if necessary.

SystemicAnomaly
11-27-2009, 05:03 PM
Is this your own analysis? What other sources did you use?

For the most part, it is my own analysis. I have refined my thinking on the subject in the past couple of years after studying the work of Joan Vickers (The Quiet Eye technique) and the theory of Mark Papas (Revolutionary Tennis).

I have also studied high speed film of Federer tracking the ball. I've posted a link to one of those videos in a previous thread or 2.
.

SystemicAnomaly
11-27-2009, 05:09 PM
Do you just ask them to watch the ball? In a kind of abstract way? Or do you give information? This question is not about how you do it. You explained that. It is more about the watching!

No, I ask them to keep the head still with the eyes fixated on the expected contact point. This starts just before contact (as the forward swing commences) until the follow-thru is (nearly) completed. If the student does this, then "watching the ball" pretty much takes care of itself.

SystemicAnomaly
11-27-2009, 05:27 PM
Well, I do. I actually go out of my way to get them to understand that our eyes capture snapshots at the rate of 20 - 30 per second ...

Do you have a source that indicates that our eyes actually capture snapshots at the rate of 20-30 per second? I know that our eyes can be fooled by movie film (or broadcast images) that occur at a rate of 24 to 30 frames/second. This phenomenon is often contributed to persistence of vision but may actually due to phi phenomenon (http://en.wikipedia.org/wiki/Phi_phenomenon) and/or beta movement (http://en.wikipedia.org/wiki/Beta_movement). Whatever, the reason for the motion picture illusion, I do not believe that it implies that our eyes actually view real motion in snapshot fashion.

jswinf
11-27-2009, 05:29 PM
Very important for me right now is to know from you and others why you fail to watch the ball. I know the feeling. But if you say it, it sounds like it is one of the most important things we have to do.

Nobody can play tennis without watching the ball at all, but the quality of the "watching" and the concentration on it varies. I said before that I'm often pleasantly surprised when I "remember" to really concentrate on watching the ball. Why don't I do it all the time? Sometimes I'm thinking more about the latest pearl of wisdom I read on TT, sometimes I'm trying to see Jupiter or Venus (the planet) too much, sometimes I just space out. If I could do a high quality job of watching the ball without having to concentrate on doing it, I'd certainly be a better player. Repitition doubtless helps, so does natural ability.

nabrug
11-27-2009, 05:57 PM
Nobody can play tennis without watching the ball at all, but the quality of the "watching" and the concentration on it varies. I said before that I'm often pleasantly surprised when I "remember" to really concentrate on watching the ball. Why don't I do it all the time? Sometimes I'm thinking more about the latest pearl of wisdom I read on TT, sometimes I'm trying to see Jupiter or Venus (the planet) too much, sometimes I just space out. If I could do a high quality job of watching the ball without having to concentrate on doing it, I'd certainly be a better player. Repitition doubtless helps, so does natural ability.

This is very important for me. Thanks. I would really like to know what you are really thinking at these moments. I think the spacing out thing is what people will recognize most I think. If you can be more specific I really would like to hear it.

Do people recognize this? Or are you always watching the ball? Without any effort. Besides that I want to know what teachers say to you to help you if you are distracted? Or if you are a teacher how do you help a player who has problems concerning concentration?

nabrug
11-27-2009, 05:59 PM
This is a question to all readers:

Do people recognize this? Or are you always watching the ball? Without any effort. Besides that I want to know what teachers say to you to help you if you are distracted? Or if you are a teacher how do you help a player who has problems concerning concentration?

5263
11-27-2009, 07:44 PM
This is a question to all readers:

Do people recognize this? Or are you always watching the ball? Without any effort. Besides that I want to know what teachers say to you to help you if you are distracted? Or if you are a teacher how do you help a player who has problems concerning concentration?

Watching the ball into contact was my biggest breakthru in becoming a more consistent player. Back in the 80's, I got serious about my tennis play several times, only to improve to a point, then start crashing down to worse and worse play, only to quit for 6 mos-1.5yrs before coming back to the sport each time.

In early 90s I decided to hang in there when my game got ragged and figure out why-Whatever it took! Sure enough, I improved to a point (around 4.0) then started to get ragged again, just like all the other times. Not sure what got me on it, but found that the prob was looking away before contact. Probably a combination of poor vision technique and head movement. Realized it came from over confidence in my stroke and being curious of what the opp was doing; cause when I was less confident, I tried harder to focus on the contact visually and hit much better. Once I learned to stay with the ball into contact and leave my head still a moment after like they teach punters and kickers in football, then my game was able to continue to zoom right on up to thru several levels.

I found that if I made watching the ball with a still head, a major focus in my warmup, then I could forget about it during my play in matches for the most part. It worked sort of like loading an operating system like we used to have to do on our PC. Around this same time I learned the importance of hitting more out front. Part of the help here was hitting out front allowed me not to need to move the head very much to the side to see the contact. I found that anytime I started to mishit or not hit cleanly, I would use the mishit as a key to focus more on head still and watching the contact. This always worked and later on, was real helpful for students I shared this with, as I began to instruct. It was interesting to learn about Jump saccades and such, to know what I was doing naturally, but didn't need to know how it worked really, as your system knows how to do it when asked to accomplish certain tasks such as IMO, watch the contact.

SystemicAnomaly
11-28-2009, 06:04 AM
Yes, but Papas also points out how this is how it is normally done, without special coaching. The coaching mainly deals with where you jump to, not that you jump ahead.

As for what you find yourself doing, that would be natural given your perspective on the subject, but that would not mean it is needed.

It occurs to me that you might be operating under the notion that I routinely tell students to execute a jump saccade. I do not. Unless they ask why it is important to focus on the contact point & keep the head still, I probably won't even mention the word saccade or the fact that the eyes should "jump" to the contact zone.

I mention in these forums to dispel myths about people claiming to be able to "watch the ball all the way into the strings". I will usually emphasize keeping the head still with eye fixed on the contact zone. If students learn to do this, they automatically watch the ball to the "vanishing point" and will once again track the ball one their swing is nearly complete.

SystemicAnomaly
11-28-2009, 06:18 AM
This is very important for me. Thanks. I would really like to know what you are really thinking at these moments. I think the spacing out thing is what people will recognize most I think. If you can be more specific I really would like to hear it.

Do people recognize this? Or are you always watching the ball? Without any effort. Besides that I want to know what teachers say to you to help you if you are distracted? Or if you are a teacher how do you help a player who has problems concerning concentration?

Convergence insufficiency (I will go into detail later).

nabrug
11-28-2009, 06:26 AM
It occurs to me that you might be operating under the notion that I routinely tell students to execute a jump saccade. I do not. Unless they ask why it is important to focus on the contact point & keep the head still, I probably won't even mention the word saccade or the fact that the eyes should "jump" to the contact zone.

I mention in these forums to dispel myths about people claiming to be able to "watch the ball all the way into the strings". I will usually emphasize keeping the head still with eye fixed on the contact zone. If students learn to do this, they automatically watch the ball to the "vanishing point" and will once again track the ball one their swing is nearly complete.

Do you recognize players "spacing out" like jswinf posted? If so how do you help them?
If other people like to comment. Please!

papa
11-28-2009, 07:16 AM
Do you have a source that indicates that our eyes actually capture snapshots at the rate of 20-30 per second? I know that our eyes can be fooled by movie film (or broadcast images) that occur at a rate of 24 to 30 frames/second. This phenomenon is often contributed to persistence of vision but may actually due to phi phenomenon (http://en.wikipedia.org/wiki/Phi_phenomenon) and/or beta movement (http://en.wikipedia.org/wiki/Beta_movement). Whatever, the reason for the motion picture illusion, I do not believe that it implies that our eyes actually view real motion in snapshot fashion.

Well, I know I should be able to produce a reference after making a comment like that. However, without sounding too dumb, I have seen several references to that figure over the years but your much more into this than I. I have followed with interest your thought/comments on this subject and will if possible look through my references to see if I can find anything. One of the problems, certainly not an excuse, is that I live in two areas and I cannot transport everything back and forth - most of my books/tennis material is not here with me unfortunately.

However, I believe with some certainty, that the figures of 20 - 30 frames per second is accurate. Perhaps others can chime in here and help me out a spec.

SystemicAnomaly
11-28-2009, 02:02 PM
^ I am familiar with the idea of "catch-up" saccades (slightly different than the jump saccade I mentioned earlier). The eyes might periodically perform some micro-saccades when tracking using smooth pursuit. However, I don't believe that this is the same as the frame concept that you are referring to. Will have to look closer into how the brain actually processes visual information from the eyes.

5263
11-28-2009, 04:12 PM
I've also heard the frame rate references as it relates to calling lines.
Like if a hard serve hits the back of the line, then as it rolls or skids well off the line before bouncing up. In this situation your eyes may capture a frame of it on the back part of the line or maybe after it has left the line (appearing to be out), or miss the contact portion of the bounce completely, leaving the brain to fill in and decide where the ball hit.

jswinf
11-28-2009, 05:48 PM
[QUOTE=nabrug;4152495]I would really like to know what you are really thinking at these moments. I think the spacing out thing is what people will recognize most I think. If you can be more specific I really would like to hear it.

I don't really want to be famous for spacing out, I don't think I'm unique in that respect. It's sort of like what the humorist Dave Barry used to write about a husband's answer when his wife asks "what are you thinking about?" Sometimes, nothing at all, just like a low hum in there. Sometimes, like I said, thinking/worrying about other mechanics like moving the feet, grip, follow-through, whatever intrude. Or being quietly huffy about a bad call or something. Hopefully I'll do better after thinking about it this much!

SystemicAnomaly
11-29-2009, 06:23 AM
I've also heard the frame rate references as it relates to calling lines.
Like if a hard serve hits the back of the line, then as it rolls or skids well off the line before bouncing up. In this situation your eyes may capture a frame of it on the back part of the line or maybe after it has left the line (appearing to be out), or miss the contact portion of the bounce completely, leaving the brain to fill in and decide where the ball hit.

Not heard this either. Any references?

The only mention that I've come across with respect to seeing the world in frames is with certain neuropsychological disorders, such as akinetopsia (motion blindness). There is also the matter of saccadic suppression (or saccadic masking). With this phenomenon the brain suppresses visual information when the eye performs a saccade.

With regards to calling lines, I've spoken to several lines persons (certified for pro tennis). They have been taught, not to track the ball when it is bouncing near or on a line. Anytime a ball appears to be encroaching a line of interest, the lines person may track the ball long enough to determine the approx part of a line the ball may bounce. However, before that ball reaches the line, the lines person quickly shifts their gaze to that part of the line so that both the head and the eyes are not moving when the ball bounces. If either the head or the eyes are moving as the ball bounces, it has been found that the ability to accurately detect the bounce point is severely hampered.



Do you recognize players "spacing out" like jswinf posted? If so how do you help them?
If other people like to comment. Please!

Will try to come back to this later today (and will explain convergence insufficiency).

nabrug
11-29-2009, 06:35 AM
Not heard this either. Any references?

The only mention that I've come across with respect to seeing the world in frames is with certain neuropsychological disorders, such as akinetopsia (motion blindness). There is also the matter of saccadic suppression (or saccadic masking). With this phenomenon the brain suppresses visual information when the eye performs a saccade.

With regards to calling lines, I've spoken to several lines persons (certified for pro tennis). They have been taught, not to track the ball when it is bouncing near or on a line. Anytime a ball appears to be encroaching a line of interest, the lines person may track the ball long enough to determine the approx part of a line the ball may bounce. However, before that ball reaches the line, the lines person quickly shifts their gaze to that part of the line so that both the head and the eyes are not moving when the ball bounces. If either the head or the eyes are moving as the ball bounces, it has been found that the ability to accurately detect the bounce point is severely hampered.

Can you give your sources? Where did you study? What literature did you read? Did you write articles about this? etc..

SystemicAnomaly
11-29-2009, 09:55 AM
Can you give your sources? Where did you study? What literature did you read? Did you write articles about this? etc..

My area of university study was actually in Engineering Technology (Calif Polytechnic, SLO). My knowledge & study of the human visual system is something of a personal obsession/hobby. I engaged in a sports vision training program with a behavioral optometrist in the late 1980s. Learned quite a bit about vision & visual tracking, during that training. However, my knowledge of the subject is hardly comprehensive -- there is quite a bit that I don't know about this stuff.

I have skimmed thru various journal articles on vision-related studies. However, for the most part, much of these are somewhat over my head. If you are interested in those types of sources on akinetopsia, you might take a look at the following:

http://www.jneurosci.org/cgi/reprint/11/2/454.pdf
http://www.jneurosci.org/cgi/reprint/9/5/1628.pdf

If that is more than you were looking for then you might try some google searches on some of the keywords that I've mentioned. Some information can also be gleaned from wikipedia (some articles are better than others). Here are a couple that may be of interest:

http://en.wikipedia.org/wiki/Motion_perception#Neuropsychology
http://en.wikipedia.org/wiki/Phi_phenomenon
.

SystemicAnomaly
11-29-2009, 09:58 AM
Another couple of related articles:

http://www.hhmi.org/senses/b210.html

http://en.wikipedia.org/wiki/Saccadic_masking
.

5263
11-29-2009, 10:01 AM
With regards to calling lines, I've spoken to several lines persons (certified for pro tennis). They have been taught, not to track the ball when it is bouncing near or on a line.

Your use of the term "tracking" may be consistent with the science community, but I think track is an excellent word for what actually happens with the eye following something smoothly when it can, then shifting to pick it up in spots once it can't follow it continuously. If you are tracking a deer and lose the trail for a moment, then pick it up a little farther down, that is all part of tracking the animal. Just cause it couldn't be followed for awhile didn't mean you were not still tracking in the overall situation of tracking the animal, as that is part of Tracking. Or like tracking a package with Fedex. It just gives you a shot of where the package has been at times, not where it is continuously.

Seems what you say should be watching or seeing, which is continuous, vs tracking, which accounts for spaces of no data. Also this important since we are not working with vision phd's too often, so tracking would be a good term for making this point with the avg Joe based on the normal uses of the word.

TenniseaWilliams
11-29-2009, 10:49 AM
Overall, most studies suggest that the human eye has no intrinsic "frame rate".

This http://www.100fps.com/how_many_frames_can_humans_see.htm page is a pretty easy read through the subject.

The http://en.wikipedia.org/wiki/Wagon-wheel_effect has some references to recent human eye temporal sampling theory and studies. (near the end of the article) The article is fairly easy to wade through and makes some interesting points.

W Cats
11-29-2009, 04:09 PM
TennisOne had a series of articles about what S.A. is referring to. I don't currently have a subscription so I can't accurately reference it . But as I recall one of the issues beside what the eye can track accurately at speed is how fast the eye/brain can process the information. One type of vision allows for the brain to tune into detail of an oncoming object such as: brown, almond shape, two white strips, football, direction of travel approximate speed and trajectory. The other more peripherally oriented vision the brain processes at several times the speed of the previously mentioned by only tuning into the speed and trajectory of the object. Jump saccade allows the eye/brain to tap into the second type of faster processing.

SystemicAnomaly
11-30-2009, 01:51 PM
Your use of the term "tracking" may be consistent with the science community, but I think track is an excellent word for what actually happens with the eye following something smoothly when it can, then shifting to pick it up in spots once it can't follow it continuously. If you are tracking a deer and lose the trail for a moment, then pick it up a little farther down, that is all part of tracking the animal. Just cause it couldn't be followed for awhile didn't mean you were not still tracking in the overall situation of tracking the animal, as that is part of Tracking. Or like tracking a package with Fedex. It just gives you a shot of where the package has been at times, not where it is continuously.

Seems what you say should be watching or seeing, which is continuous, vs tracking, which accounts for spaces of no data. Also this important since we are not working with vision phd's too often, so tracking would be a good term for making this point with the avg Joe based on the normal uses of the word.

Seriously? You are taking issue with my use of the word "tracking" in that context. Slow posting day or are you just trying to get in the last word (CYA)?

If you've really been reading & following my posts, it should be apparent that I am primarily using this word to mean smooth pursuit tracking (it's a bit tedious spelling out the whole phrase all the time). Most English words have multiple meanings or connotations. It should be fairly obvious, even to non-PhD's, that I'm using the word in a specific way.

I meant what I said in the previous post. A good lines person will actually stop tracking (or watching) the ball before the ball bounces on or near a line of interest. Their eyes fixate on a portion of the line, laying in wait for the ball to come into view & bounce. The foveal (central) vision is trained on the outside edge of that line segment, with the head kept very still.

Does this sound familiar? This is very similar to what Federer and other pros do when they are playing a shot? As the player commences their forward swing they actually stop tracking, or stop watching, the ball. Their eyes lose sight of the ball shortly before contact and they do not make an attempt to follow the ball coming off the strings. If they are still watching (or trying to watch) the ball as people suggest, the head & eyes would move as soon as contact is made in a (futile) effort to see the ball. This is not the case -- I'll say it again -- elite players will stop watching the ball during their forward swing.

SystemicAnomaly
11-30-2009, 01:54 PM
Overall, most studies suggest that the human eye has no intrinsic "frame rate".

This http://www.100fps.com/how_many_frames_can_humans_see.htm page is a pretty easy read through the subject.

The http://en.wikipedia.org/wiki/Wagon-wheel_effect has some references to recent human eye temporal sampling theory and studies. (near the end of the article) The article is fairly easy to wade through and makes some interesting points.

TennisOne had a series of articles about what S.A. is referring to. I don't currently have a subscription so I can't accurately reference it . But as I recall one of the issues beside what the eye can track accurately at speed is how fast the eye/brain can process the information. One type of vision allows for the brain to tune into detail of an oncoming object such as: brown, almond shape, two white strips, football, direction of travel approximate speed and trajectory. The other more peripherally oriented vision the brain processes at several times the speed of the previously mentioned by only tuning into the speed and trajectory of the object. Jump saccade allows the eye/brain to tap into the second type of faster processing.

Thanks for this great feedback guys. W Cats, do you recall when TennisOne presented these articles? Is it possible that some or all of it is posted in archives of their free newsletter?

5263
11-30-2009, 02:34 PM
Seriously? You are taking issue with my use of the word "tracking" in that context. Slow posting day or are you just trying to get in the last word (CYA)?



No need to be rude. I realize that you think tracking is mostly for the smooth aspect. I agreed that your terms were probably correct from a science use, so no need to be ultra sensitive and lash out. But since you did, maybe the issue of you coming in on any discussion related to vision, and correcting other peoples terms to conform to that you have read on your hobby subject may not be the best way to approach it in this medium.
Especially since tracking is probably the best word (based on common usage of it) to describe the whole event, moving from smooth to the jump saccade.
And of course no one else is going to get the last word on "eye on the ball" as long you are on the forum, so no, I had no illusions of that.

W Cats
11-30-2009, 02:38 PM
S.A. This was a series of articles on Parallel Processing written by Scott Ford. He also wrote a book called In the Zone. It was pretty interesting stuff.

Here is a link to an accompanying article that he wrote. It does not however contain the information about prcessing speed of detail vs. speed/trajectory.

http://www.tennisone.com/magazine/classics/parallel/mode.php

SystemicAnomaly
11-30-2009, 02:40 PM
This is a question to all readers:

Do people recognize this? Or are you always watching the ball? Without any effort. Besides that I want to know what teachers say to you to help you if you are distracted? Or if you are a teacher how do you help a player who has problems concerning concentration?

The larger question is, are you watching the ball when it should be watched and fixating on the contact zone (with the head kept still) during the appropriate time (usually during the forward swing)? I'm fairly certain that I almost always watch the ball when I should. However, the 2nd part is the more difficult one. I'm usually very good about fixating on the contact zone with the head still for 2 or 3 sets, but this tends to break down for a couple of reasons.

The primary reason for this breakdown is a combination of convergence insufficiency and visual/mental fatigue. I'll come back to this a bit later. The other reason for the breakdown is because I'm teaching a lot more than I am playing these days. The problem is something of a occupational hazard. I am usually feeding balls to students and watching their actions rather than focusing on the flight of the ball. I will often hit balls back without fixating on the contact zone so that I can clearly see what they (the student) is doing -- are they recovering? split-stepping as I make contact? are they still moving as I am about to make contact? are they in balance? the appropriate location? etc?

So, when I go back to playing, I've got to retrain myself not to do this. I constantly find myself practicing the "quiet eye" when I warm up and between points (before the ball is put into play).

Convergence insufficiency (CI) is a visual problem where my eyes prefer not to converge -- the outside muscle of the eyes win out over the eye muscles that are used for convergence. I have a very difficult time sustaining eye convergence for near and even mid-range objects in my field of vision. This is a congenital problem that is not uncommon. I do not have any figures on how common this disability is but I do know several other people with the same disorder. I did not find out about this learning disability until I had already graduated from college. Because of CI, my eyes fatigue easily when reading printed material or when using a computer monitor. In 10-15 minutes of reading, I will feel considerable eye strain due to close convergence.

The CI problem was discovered when I engaged in sports vision training some 20+ yrs ago. It explained why I got headaches when reading a book or monitor and why my hand-eye coordination seemed to be slightly off when playing sports such as tennis. The vision training did not cure the CI but it did improve my visual stamina in this regards. After the training, I was able to read a book for nearly 30 minutes at a time instead of only 10-15 minutes.

My hand-eye and visual stamina improved for sports as well. However, after a couple of sets or so, I start feeling the eye fatigue which, in turn, produces mental fatigue. Even for those people that do not have CI, visual and mental fatigue will play a role in the ability to sustain the proper ball tracking and "quiet eye" techniques.
.

5263
11-30-2009, 02:41 PM
S.A. This was a series of articles on Parallel Processing written by Scott Ford. He also wrote a book called In the Zone. It was pretty interesting stuff.

Here is a link to an accompanying article that he wrote. It does not however contain the information about prcessing speed of detail vs. speed/trajectory.

http://www.tennisone.com/magazine/classics/parallel/mode.php

Also a book call Design B.

RafaBrain
11-30-2009, 11:47 PM
I have played for 40 years and having watched Federer slo-motion videos saw that he kept his head down on the ball as close as humanly possible until it struck his racket.

Most of us have a tendency to follow the ball but not TRY to watch it hit the racquet head.
We tend to look up at where the ball is going as we strike it..

What I am going to say is very subtle and difficult to do because of the inclination to see where the ball is going after you strike it. But I have been doing the following lately and it has significantly increased my consistency.

I follow the ball as it strikes the opponents racket and as it is crossing the net and coming to either my BH or FH I take a snapshot of the court and decide where I am going to attempt to hit the ball (i.e. DTH, CC, Drop, etc.) Now here is the most important and difficult part (only difficult due to habit). I watch the ball hit my racket head and only after I strike it do I look up.. I agree that there is only a millisecond difference between this technique and the other way where you strike and look up almost simultaneously.

But for me I find that I hit the ball much more consistently and have fewer frame shots.
It also stops me from lifting up my shoulder when striking the ball which tends to keep the ball from flying deep.

Now, I am a 3.5 player so take that into consideration..

Ken

.
I have learned some nice things about when to keep eyes on the ball from book <Tennis Kung Fu>.

5263
12-01-2009, 04:16 AM
.
I have learned some nice things about when to keep eyes on the ball from book <Tennis Kung Fu>.

Could you share some of those points?