rfprse
Professional
Got it. Is there any difference between shooting the speed gun behind the player and in front of the player?
Serve speed cage
- Thread starter raiden031
- Start date
Leelord337
Hall of Fame
ooopz 10 char
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J011yroger
Talk Tennis Guru
J011yroger
Talk Tennis Guru
Now if I could just figure out how to use this power to actually win a match lol.
J
J011yroger
Talk Tennis Guru
I have a 2nd little baby tripod, and I was tempted to put the speed trac up on it, and make it exactly the hight of the net to try to cut out some angle error from the radar resting on the ground, but knowing me, on my very first serve I would hit the thing and that would be the end of that.
J
J011yroger
Talk Tennis Guru
Maybe I could use a soccer goal?
I'm not exactly keen on the idea of serving into a chain fence from close range.
J
J011yroger
Talk Tennis Guru
109 was with the wooden racquet
Hit 112 with my 14.3 oz strung at 70lb Luxilon ALU Rough racquet.
My back was bothering me and it was getting dark so hard to see (I am effectively blind at dusk) so I didn't really turn it loose.
If my back isn't stiff I'll go out this weekend and try to put up a big number now that I am curious.
If you come up with some more stuff for me to try I will do it this weekend.
J
Cindysphinx
G.O.A.T.
How much difference does it make that Jolly is taller than I am? (I don't know this for a fact, but everyone is taller than I am!).
I would think that Karlovic's 33 mph serve would hit the fence, whereas Michael Chang would need a lot more mph.
Then again, I know nothing of science or physics or stuff like that.
I would think that Karlovic's 33 mph serve would hit the fence, whereas Michael Chang would need a lot more mph.
Then again, I know nothing of science or physics or stuff like that.
drakulie
Talk Tennis Guru
Guys, the speed trac measures speed in an area in front of it. In other words, if it is placed directly on the net, it will pick up the speed of the ball as it approaches the net>> Not directly at the net.
When mike and mav did testing of my serve speed measured against the radar on my vid, it was determined the speed trac was off by about 5-7 mph.
What I mean when I say "off", is if my serve speed would have been picked up as it left the racquet face (like they do in pro tournaments), as opposed to when it approached the net, my serve would have been 5-7 mph faster than what the speed trac measured.
jolly, good stuff!! Thanks for taking the time to do this. Much appreciated.
When mike and mav did testing of my serve speed measured against the radar on my vid, it was determined the speed trac was off by about 5-7 mph.
What I mean when I say "off", is if my serve speed would have been picked up as it left the racquet face (like they do in pro tournaments), as opposed to when it approached the net, my serve would have been 5-7 mph faster than what the speed trac measured.
jolly, good stuff!! Thanks for taking the time to do this. Much appreciated.
drakulie
Talk Tennis Guru
Put the speed trac behind the fence, and serve at the fence.
fruitytennis1
Professional
Im quoting myself... Well so this would be about correct if your talking about speed from the racquet face right???
5263
G.O.A.T.
yep, Cindy, those things matter.
That's where the common sense comes in with general rules of thumbs. you have to take the flyers out of the equation.
canadave
Professional
That might work, though, if you just secured the tripod to the net with some cord. That way if it gets hit, it doesn't get knocked over. The only way it'd be damaged is if you hit the gun itself and hit it so hard with the ball that you damaged its sensitive electronics
drakulie
Talk Tennis Guru
^^^LOL. Don't try it. I did, and came extremely close to hitting the radar. Not worth it, IMO.
Here is a vid I took of the moment:
I placed the radar on the opposite side of the net (more than half way up) the service line:
http://www.youtube.com/watch?v=uvs1-q9ip5E
If I would have hit the radar, it would have surely smashed the poor thing.
Here is another one, although It didn't come as close to the first one:
http://www.youtube.com/watch?v=OjBOV9zsrps
Here is one I took, where I hit the camera. The camera was mounted on the fence, about 5 feet up. (fence, 23 feet from baseline): (luckily, the camera didn't break).
http://www.youtube.com/watch?v=FGWip2F_e7M
Here is a vid I took of the moment:
I placed the radar on the opposite side of the net (more than half way up) the service line:
http://www.youtube.com/watch?v=uvs1-q9ip5E
If I would have hit the radar, it would have surely smashed the poor thing.
Here is another one, although It didn't come as close to the first one:
http://www.youtube.com/watch?v=OjBOV9zsrps
Here is one I took, where I hit the camera. The camera was mounted on the fence, about 5 feet up. (fence, 23 feet from baseline): (luckily, the camera didn't break).
http://www.youtube.com/watch?v=FGWip2F_e7M
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5263
G.O.A.T.
good stuff Drak.
Cindysphinx
G.O.A.T.
Good grief.
As promised, I went out and tried to hit the back fence before the second bounce.
First, I paced off the distance of the back fence. It was the length of 21 size 9 Gel asics, so that sounds about right.
The court itself is an old, fairly smooth green court. The fence on these courts kind of keeps going well past the doubles alley, kind of bending away. Meaning that any serve hit to the corners has a very long way to travel before making it to the fence. There are two courts; the net on one of them is screwed up and is too high.
OK. I set up my hopper on the court with the too-high net because it was in the shade. After hitting some warm-up serves, I knew I was in deep trouble with this experiment. Most of my initial serves went into the net, probably because I was trying to hit them so hard and because the net was too high.
Of major concern was the fact that none of the serves that did go in were coming anywhere close to hitting the fence. Indeed, they seemed to be doing the opposite: staying very low.
I started troubleshooting. I changed my grip to be more Eastern FH. Nope. Grip change past Continental. Nope. More knee bend. Higher toss. Lower toss. Different toss location. More weight transfer. More slice. Serve from a singles position. Serve from a doubles position. Nope, nope, nope. Even balls that sailed well past the service line sometimes didn't make the fence on the second bounce.
Then I wondered if it could be the balls, because many of my hopper balls are ancient. I grabbed some newer balls out of my bag and opened a new can of balls, so now I was enduring the frustration of serving with just eight balls. I went over to the other court with the correct net and the blazing sun and tried again.
Oh, I was so close! I didn't count a ball as successful unless I was 100% certain it was in and I was certain the second bounce hadn't hit the ground first. Many balls were too close to be sure. I continued tinkering. I kept this up for just over an hour.
Finally, I isolated the variable that made the most difference: Focusing mostly on the racket drop, which produced a higher-bouncing ball.
I was just about to give up when *finally* one ball from the deuce court hit the T, kicked up and hit the fence.
I have two reactions.
First, I am not sure that this little experiment means I have a terrible, 33 mph serve. I hit a lot of serves today that I would be happy to serve on triple match point down against 4.0 players. Many would have produced poachable balls or defensive replies. Many of my balls had so much slice that they would cause geometry to work against me, especially if I was serving toward those deep fence corners. Or I would really nail one, but it wouldn't go down the T and instead would go well wide. Or they were the low skidding type that many opponents find difficult to attack.
Second, the exercise was valuable because I really got a chance to focus on exactly what my ball was doing and why. Usually, I practice either form (to fix some problem I have been having), or I work on placement.
So yes. I guess I can now say that I served a ball that hit the back wall before the second bounce. Someday I will decide if it was worth all the trouble.
As promised, I went out and tried to hit the back fence before the second bounce.
First, I paced off the distance of the back fence. It was the length of 21 size 9 Gel asics, so that sounds about right.
The court itself is an old, fairly smooth green court. The fence on these courts kind of keeps going well past the doubles alley, kind of bending away. Meaning that any serve hit to the corners has a very long way to travel before making it to the fence. There are two courts; the net on one of them is screwed up and is too high.
OK. I set up my hopper on the court with the too-high net because it was in the shade. After hitting some warm-up serves, I knew I was in deep trouble with this experiment. Most of my initial serves went into the net, probably because I was trying to hit them so hard and because the net was too high.
Of major concern was the fact that none of the serves that did go in were coming anywhere close to hitting the fence. Indeed, they seemed to be doing the opposite: staying very low.
I started troubleshooting. I changed my grip to be more Eastern FH. Nope. Grip change past Continental. Nope. More knee bend. Higher toss. Lower toss. Different toss location. More weight transfer. More slice. Serve from a singles position. Serve from a doubles position. Nope, nope, nope. Even balls that sailed well past the service line sometimes didn't make the fence on the second bounce.
Then I wondered if it could be the balls, because many of my hopper balls are ancient. I grabbed some newer balls out of my bag and opened a new can of balls, so now I was enduring the frustration of serving with just eight balls. I went over to the other court with the correct net and the blazing sun and tried again.
Oh, I was so close! I didn't count a ball as successful unless I was 100% certain it was in and I was certain the second bounce hadn't hit the ground first. Many balls were too close to be sure. I continued tinkering. I kept this up for just over an hour.
Finally, I isolated the variable that made the most difference: Focusing mostly on the racket drop, which produced a higher-bouncing ball.
I was just about to give up when *finally* one ball from the deuce court hit the T, kicked up and hit the fence.
I have two reactions.
First, I am not sure that this little experiment means I have a terrible, 33 mph serve. I hit a lot of serves today that I would be happy to serve on triple match point down against 4.0 players. Many would have produced poachable balls or defensive replies. Many of my balls had so much slice that they would cause geometry to work against me, especially if I was serving toward those deep fence corners. Or I would really nail one, but it wouldn't go down the T and instead would go well wide. Or they were the low skidding type that many opponents find difficult to attack.
Second, the exercise was valuable because I really got a chance to focus on exactly what my ball was doing and why. Usually, I practice either form (to fix some problem I have been having), or I work on placement.
So yes. I guess I can now say that I served a ball that hit the back wall before the second bounce. Someday I will decide if it was worth all the trouble.
pabletion
Hall of Fame
Can someone proove this mathematically? Im sure some one in this forum has it. Somehow, a drop from 140mph to 90 before it touches the surface seems too much. Appreciate it!
5263
G.O.A.T.
try checking this link and see what you think.
http://www.popularmechanics.com/outdoors/sports/4221210.html?page=5
IMO it would suggest that Draks numbers were off far more than 5-7mph, that vid measurements came up with.
Not sure what the vid error introduced would be, but I'm sure MIke is. Frame count can be off, distance can be off, math error, etc.... plus there is the built in margin for error as well.
Maybe Mike can comment on his experience with this.
5263
G.O.A.T.
Yes, ....but too not far out unless they have improved newer machines. It used to be out only about < 12'.
Do you have numbers for your radar's pick up area?
yes it will get you walking up from farther, but you are a big target and slow. The ball is very small, fast, and slowing quickly, all of which is a big challenge for the radar.
Your 82 on the receivers svc line should be well over 100 off the racket face.
Are you saying that it would only be an 87?
Mike Cottrill
Hall of Fame
For best results to get max velocity from a radar gun, see this:
http://www.astroproducts.net/PDF/Sports_Radar/Tennis_Position_Instructions.pdf
If all your concerned with is consistency, then just place the radar gun in the same spot all the time.
Speed Cal and Video:
The main assumptions for the derivation of the formula for the speed calc:
- The motion of the ball after the hit is only affected by the drag force of the air alone, which is assumed to be proportional to the square of the velocity. There is the obvious force of gravity, but being a vertical force, it doesn't significantly affect the calculation.
- A V0 mph serve slows down to Vf mph over S feet. We need these numbers from some external source such as this website reporting a study done on Sampras' serve
Example:
http://www.donthireddy.us/tennis/RoddickExample.html
The largest source of error is calculating the distance the ball travels from frame to ball contact and ball to surface contact.
From the example in the above link:
Here are speed readings with slightly different distance readings:
- 58.84’ == 139.04mph
- 58.50’ == 138.10mph
- 58.25’ == 137.41mph
- 58.00’ == 136.73mph
That is why I suggested to J to use powder and string measuring from ground contact and where he made contact with the ball (that includes tying the sting to the face of the racquet and holding it up to were ball contact was made) to get an accurate distance measurement.
If the video is shot at 120/240 frames/fields per second or higher, the contact error times are not significant. At 30 or 60 frames/fields per second, the error goes up. The majority of the time, at slower frame rates the camera will not capture the impacts.
IMO, if a high frame rate is used and the distance is measured at the court, this will provide a more accurate max velocity reading than a radar gun; including what the ATP uses. I would like to see more data shared on shot spot. They should be able to calculate velocities from the footage they take.
5263
G.O.A.T.
Great stuff Mike.
and nice link on that radar set up.
I've seen some stuff by hawk-eye but can't seem to find it again. They are able to pull speeds all along the flight of the ball.
I don't want to act like everyone is serving 155 mph out there, but there is this idea that a club player can't possibly hit 135, cause some pros don't do that, and that's just wrong.
Club players can often hit as big or bigger than many pro do in matches.
( sort of like how drive contest in golf hit longer than tour players.)
Club players don't have to hit their spots.
Club players don't have to win. (many of the bigger club servers I've known were not that tough to beat)
If pros don't win, you never hear about them long, no matter how fast they serve.
Club players don't often have a great all around game and can excel on focusing on the serve.
Club players have often been pitchers and QBs (or even tennis and volleyball) in early years.
I usually play with pretty good players, so I see lots of good serves. I also see lots of very avg serves and tons in-between.
I guess I'm just a glass half full kind of guy. I tend to focus on what CAN be done opposed to what is just some kind of average.
I believe you go where your focus is.
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drakulie
Talk Tennis Guru
No!! LOL. Sorry if I confused you.
The speed trac picks up the speed of the ball as it approaches the radar. Therefore, wherever you put it, there is a zone in front of it (can't remember off hand the measurement) where it will pick up the speed. I believe it is somewhere in the 10-15 foot range????
So, lets say I put the speed trac on the opposite baseline, which is 78 feet away from the baseline I'm serving from..... By the time the ball reaches about 10-15 feet in front of the radar, it will pick up the speed the ball is traveling at that point>>>> not the speed when it left the racquet, nor when it crossed the baseline.
1. My serve video where I hit a 108 mph serve, the radar was in front of the net facing me. So, it picked up the serve (108 mph) as it approached the radar. However, when Mike/Mav looked at the video and put in their formula, they concluded my serve was 5-7??? mph faster (at contact), than what the radar provided.
2. In this video, http://www.youtube.com/watch?v=uvs1-q9ip5E, the radar was placed on the other side of the net, and much further than my video with the 108 mph serve. As you could see, it registers a 92 mph ball approaching it. In this video: http://www.youtube.com/watch?v=OjBOV9zsrps, it resgisters the ball approaching it at 98 mph. However, being that the radar was further away from the contact point, explains why the ball was traveling slower than when I put the radar in front of the net, like in my 108 mph video.
3. In this video: http://www.youtube.com/watch?v=Uo4bkssVVY4&feature=related, I placed the radar directly on the baseline, and it register a ball approaching it at 79 mph. Again, the speed seen here, is more likely the speed as it approached the opposite service line.
4. Lastly, the video seen here: http://www.youtube.com/watch?v=LKLUEvGwIes&feature=related, on the back fence, which is 23 feet away from the baseline, resgisters the ball approaching at 43 mph, and most likely is the speed as it approached the baseline, not when it reached the fence.
Hope this all made sense.
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WildVolley
Legend
Sometimes they animate a ball path (I think they call it shot tracker) and give a mph reading.
One of the most exciting things about shot spot is that it should allow detailed statistics on the professional game to be developed.
Mike Cottrill
Hall of Fame
Last few times I have seen Roddick on TV, it looks like he does not believe the machines..
drakulie
Talk Tennis Guru
perhaps he should submit a video here at TW, in the 100 mph club thread, and have us take a look at it?
5263
G.O.A.T.
I agree totally.
Drak,
So you agree your serves are in the 115 range, which would have been my estimate based on your different placement areas. right?
5263
G.O.A.T.
Yes, I meant about a min of 115.
We should all know that doesn't mean everyday, as sometimes you just hit better or cleaner. Some events Roddick never goes over 141, but we all know he can and has gone over 150. I think it is pretty clear that you can be in the 120s on your good days.
fruitytennis1
Professional
That is one sick serve drak. If only... Well ill be content with my about 60-80mph twist and topspin serves. I wanna be able to serve like that when im older.
Ultra2HolyGrail
Hall of Fame
aptennis91
Rookie
How old are you? If you are older than 16, you should at least give it a go.
60-80mph twist and topspin are still pretty sick.
fruitytennis1
Professional
Im 15 years old.
aptennis91
Rookie
wow.. I wish I had a 60-80mph kick serve at 15...
But really, at 15, your body is starting to get stronger so there isn't a reason not to try it out. Make sure to watch your shoulder though.. Rotator cuff tear at a young age is a killer.
But really, at 15, your body is starting to get stronger so there isn't a reason not to try it out. Make sure to watch your shoulder though.. Rotator cuff tear at a young age is a killer.
fruitytennis1
Professional
I dont use flat serves i just never got it.
My fastest serves which im still tweaking are topspin and slice. I think those top out at around 85-90 just not superconsistant(I like consistant first serves 65% or better) and they dont have the nice kick im used to. I will probably use them on AD side for down the line serves, once i get it atleast. I do know what im talking about when i say my serve speed just to tell you.
My fastest serves which im still tweaking are topspin and slice. I think those top out at around 85-90 just not superconsistant(I like consistant first serves 65% or better) and they dont have the nice kick im used to. I will probably use them on AD side for down the line serves, once i get it atleast. I do know what im talking about when i say my serve speed just to tell you.
aptennis91
Rookie
I wasn't doubting you at all. You seem to have it all worked out.
Although, seeing how you can hit serves at that speed with topspin, i don't think it will be that hard to start bombing flat serves once in a while with some practice.fruitytennis1
Professional
No i mean i just cant get em in unless their like 40mph or slower also the twist serve isnt 80mph(I wish it was though) the twist serve is 65mph tops.
Honestly i dont think my serves are gonna get much faster ever, mabey add some mph and some good placement and hopefully a little more kick!!
Honestly i dont think my serves are gonna get much faster ever, mabey add some mph and some good placement and hopefully a little more kick!!
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Datacipher
Banned
Wow. Pages and pages, since I was last at this thread. Thanks for the work put in Jolly.
As I said in my 2nd post in this thread:
"As to the 40mph, I've never actually tried to measure my minimum speed to hit the back fence (I've never hit one that hasn't hit the back fence...), but I estimate around 40mph, as I've hit mid 60mph serves on radar that VERY easily reach the back fence. My warm ups are sometimes much slower than that, and they easily reach the back fence. (flat) "
I am certainly willing to go with 51mph as a minimum for now. It certainly is NOT the 80-100mph estimates we got from some people! It is, as I said "VERY SLOW". I think differences in our motion/ball may account for some slight difference as well. As a good server like you would know, the QUALITY of the serve hit, makes a huge difference as to the bounce....as I explained in my pm to Raiden, it actually gets fairly difficult, for me, to slow down the ball that much, while still trying to get quality contact and extension.
fruitytennis1
Professional
What do you mean by quality like the depth/placement ect. I would assume down the t hitting the service line would be the optimal slow serve to hit the fence right??
Yesterday I had a match and got there early to practice my serves. I served 7 balls six times (42 serves). I counted 6 balls that did not hit the fence on the first bounce despite the fact that I was hitting first serves. The average ball hit the fence at knee height, and a couple of them hit waist height. One ball actually went through the fence and one got stuck in the fence (both at about waist height). I think its weird that I can go from creaming the fence to not even hitting the fence at all on first bounce when hitting first serves. And it doesn't seem like the pace of the ball is dramatically slower, but definitely slower nonetheless.
5263
G.O.A.T.
And this is what I thought you meant from the start. This makes it clear on how you get your ideas of service speed. You are accepting Jollys unadjusted speed taken from quite distance and at a off angle as the slowest.
With any reasonable adjustments, this serve is not close to 50, and clearly not close to your original 40 claim. No offense to Jolly but it is questionable if it was even in the box. Looked long to me and you can see the big cracks in the court that can greatly affect a serve bounce. He also explained that he hit a bunch of them in the unadjusted sixties that did not reach. Only when he changed form did he get one flyer that may have been long, hit a crack or rock, or who know what, did he get one at a unadjusted 51.
A one out of 40 oddball, that is not a normal flat serve attempt, doesn't break a rule of thumb.
I doubt anyone who uses this rule of thumb would have said this serve would qualify as it barely gets any part of the fence. The general idea is that it should be "hitting" the fence solidly, not dribbling barely into the fence. Sorry if that was not clear, but thought it was common sense. Drak's and Jollys vids have both proved that the normal flat serve needs to be above 70 unadjusted, just to reach the fence on one hop and that to hit it solidly and regularly it would be in the 100 range.
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I have a question for those who have knowledge on good serve technique. I'm trying to be careful to word this correctly.
When hitting a hard flat serve, should the racquet motion be such that the racquet is swinging a little bit to the right of my head (such that the head of the racquet swings kinda over my shoulder), or should it be swung directly over top of my head?
One thing I already knew is that I often have a bit of an erratic toss, which explains why sometimes I can crush the ball, and other times I hit it less cleanly and softer. I think I have most of the serve motion pretty good such as the legs, body turn, and back-scratch portions, but I've just been trying to figure out what makes the diff. between between a good serve and a bad serve.
I started experimenting and noticed that when I swing the racquet head directly over my head and can hit harder serves than if its a little to the right over my shoulder. I didn't know if this is not the right way to serve, or basically a no-brainer that you should be doing this. I'm self-taught and watched some FYB videos months ago, but haven't refreshed myself on this. Any help would be useful.
When hitting a hard flat serve, should the racquet motion be such that the racquet is swinging a little bit to the right of my head (such that the head of the racquet swings kinda over my shoulder), or should it be swung directly over top of my head?
One thing I already knew is that I often have a bit of an erratic toss, which explains why sometimes I can crush the ball, and other times I hit it less cleanly and softer. I think I have most of the serve motion pretty good such as the legs, body turn, and back-scratch portions, but I've just been trying to figure out what makes the diff. between between a good serve and a bad serve.
I started experimenting and noticed that when I swing the racquet head directly over my head and can hit harder serves than if its a little to the right over my shoulder. I didn't know if this is not the right way to serve, or basically a no-brainer that you should be doing this. I'm self-taught and watched some FYB videos months ago, but haven't refreshed myself on this. Any help would be useful.
5263
G.O.A.T.
Raiden, this is a tough one to explain, as the ball should be over your head, BUT to the side of your shoulder too. This because of the upper body tilt and making room to protect your shoulder rotator cuff area.
Look at Arod serving (Sampras too) from the front and you will see how the upper arm is almost in line with a line from shoulder to shoulder. It would be like if you stood straight up and held your arm out 90 degr to your body, but thru body tilt, you can get this line going nearly straight up. The ball will be sort of over your head, but it is tilted to the side to get the shoulder up.
Does this make sense?
5263
G.O.A.T.
look at this link. there will be a vid of andy's serve. the pic before the vid even starts will illustrate what i'm saying about the shoulders and the upper arm creating nearly a straight line a impact. It also shows where the ball will be.
http://www.popularmechanics.com/outdoors/sports/4221210.html?page=2
http://www.popularmechanics.com/outdoors/sports/4221210.html?page=2
Datacipher
Banned
Yeah. I have told you this all along, AND mentioned it in my personal message to you.
Datacipher
Banned
If you're talking to me, send me a PM. I'll explain further...
fruitytennis1
Professional
Hmm ill just make a new thread on that.
Thanks for the idea Datacipher.
Thanks for the idea Datacipher.
I've hit over 110mph on my speed trac quite often. My best was 115mph. Does that mean I really hit over 130mph? This is with the radar behind the net on the ground. I'm a bit skeptical that the ball is really going 130mph off my racquet, but maybe it is.
I think measuring the ball right off the racquet face accurately is a bit of a tough nut to crack as well, and I don't know that I would agree with that method for use in practical training. I think the ATP does it that way because the numbers are bigger. I mean 100mph is pretty good, but when Roddick or Karlovic crack one above 140mph people really ooh and ahh.
Serve speed is really not that important once you get it to a certain level. If I place even a 95mph(speed trac measured) serve well, it's either a service winner or an ace. An well spun kicker at 80mph on the returner's weaker side is money all day long. I think speed is not worth as much as people think it is.
5263
G.O.A.T.
Your serve must be up there pretty close to that.
The purpose here is about comparing Apples to Apples.
Your points are all valid otherwise.
J011yroger
Talk Tennis Guru
This is me. Dunno if you would consider my serve good or not. But on a nice warm day when my back doesn't hurt, it makes a big noise and goes like hell.
J
