Hitting intentionally off center
- Thread starter paulfr
- Start date
travlerajm
Talk Tennis Guru
I noticed Nadal making contact a bit off-center when he played Roddick at the US Open in 2004 on his return of serve. It looks quite obvious in the highlight footage.
It didn’t work, so I think he must have decided to change his approach and focused on making contact closer to the center after that.
Dartagnan64
G.O.A.T.
I doubt they do this intentionally. I've never heard a pro say they do this. Certainly the more low to high your swing the more you will tend to miss the sweet spot inferiorly. It's not intentional but simple physics.
OMG this topic again.
They don't intentionally hit off-center most of the time except in some really fine-skill strokes like a low scoop near the net. As the ball dwells on the strings, it naturally pushes down (in the common case where the ball is taken slightly after the cusp of the bounce) and deforms the strings downwards, and maybe even slides down a mm or two.
They don't intentionally hit off-center most of the time except in some really fine-skill strokes like a low scoop near the net. As the ball dwells on the strings, it naturally pushes down (in the common case where the ball is taken slightly after the cusp of the bounce) and deforms the strings downwards, and maybe even slides down a mm or two.
I know 2 ways of training off center:
1. be late with your footwork
2. misjudge the timing of contact
the beauty of these 2 points is that you can as well combine them.
why?
your shots will become unpredictable, so your opponent will stay tensioned every time you hit the ball, which will draw errors from them.
5263
G.O.A.T.
the why- would be that the center of the racket is not the only sweet spot....there are several
the how- would be that.... if they do it, it would be related to hitting tens of thousands of balls leading them to develop a certain type of contact that feels right to them. Of course they can't get it just right in every instance, but they know when it feels good with a good result and they train to repeat that sensation.
There are not several sweetspots as far as I know. There is just one sweetzone whose diameter depends on the power cutoff percentage threshold you decide, and it can be oval in shape and bulging towards high power areas dictated by racket head material distribution and lead tape placement.
golden chicken
Hall of Fame
I could swear I see Federer using the top half of the stringbed when he wants more control (like a dipping backhand pass) or when he wants to hit a drop shot. Equally, I could swear I see him hitting "in the sweet spot" when he wants extra pop.
Do I think he does it consciously? No way. But I do think he does it.
Do I think he does it consciously? No way. But I do think he does it.
travlerajm
Talk Tennis Guru
There is something in golf called the gear effect.
If a right handed player makes contact on the heel of the driver, it will rotate the club head counterclockwise due to the off-center impact. The ball will rotate in the opposite direction, balancing the the rotational moment of the impact. This tends to cause impacts on the heel of the club to have a slice or fade trajectory (curving to the right). To counter this effect, and allow golfers to hit straighter (side spin is generally undesirable), most modern drivers are designed with a convex hitting surface. It looks counterintuitive (because this means an impact on the heel will spray to the left with a launch angle error by a few degrees) but the physics of the ball-club impact demand it because the gear effect problem would be worse than this launch angle error if the surface were not convex.
In tennis, an off-center impact on the top part of the stringbed will have more topspin due to the gear effect. An impact on the bottom of the stringbed will have less topspin. So it is possible that high level players like Federer naturally evolved to harness the gear effect.
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dominikk1985
Legend
There was this guy called tennissspeed claiming top players would intentionally hit below center to make the racket twist closed at contact and create more spin and I read somewhere that below center contact can indeed generate more spin (may be @JohnYandell ?) But i doubt that players do thqt as it would also cause a loss of control and more shanks
travlerajm
Talk Tennis Guru
The effect works in the opposite direction.
SystemicAnomaly
Bionic Poster
@paulfr
By off-center, which axis are you referring to? Long axis -- towards the tip or away from the tip of the racket? I suspect that this is not the direction you are referring to. Tell me if I'm wrong but, I believe that you are talking about hitting closer to the 3 o'clock position or the 9 o'clock position of the racket face.
It is possible that the players are hitting somewhat more to the lower part a bit more. This might very well be unintentional. It could be happening because these guys are hitting with so much topspin, most of the time, the ball dips / drops quickly -- somewhat more than expected when the RPMs are high.
By off-center, which axis are you referring to? Long axis -- towards the tip or away from the tip of the racket? I suspect that this is not the direction you are referring to. Tell me if I'm wrong but, I believe that you are talking about hitting closer to the 3 o'clock position or the 9 o'clock position of the racket face.
I recall Yandell indicating that players hit the center, below the center, and above the center in nearly equal percentages.
It is possible that the players are hitting somewhat more to the lower part a bit more. This might very well be unintentional. It could be happening because these guys are hitting with so much topspin, most of the time, the ball dips / drops quickly -- somewhat more than expected when the RPMs are high.
Wait a minute. That is the opposite of what is usually claimed. (Top = 3 o'clock Bottom = 9 o'clock).
travlerajm
Talk Tennis Guru
The gear effect is very counterintuitive.
Gear Effect - What Is it? - Adam Young Golf
What is this? It sounds complicated. Well, it is – but you need to know it because I see golfers make incorrect changes to their swing all the time and getting in a right mess as a result of not understanding this. Don’t let this be you! Luckily for you, I’m going to break it […]
www.adamyounggolf.com
SystemicAnomaly
Bionic Poster
Various sweet (& other) spots on a racquet:
www.latimes.com
Rod Cross:
.
Three 'Sweet Spots' on Tennis Rackets, Professor Says
Conventional tennis wisdom is all wrong, says a physics professor who has found that a racket has 3 "sweet spots," not one, and that loose rather than taut strings will yield more cross-court winners.
www.latimes.com
Rod Cross:
.
The gear effect is very counterintuitive.
Gear Effect - What Is it? - Adam Young Golf
What is this? It sounds complicated. Well, it is – but you need to know it because I see golfers make incorrect changes to their swing all the time and getting in a right mess as a result of not understanding this. Don’t let this be you! Luckily for you, I’m going to break it […]www.adamyounggolf.com
I didn't mean that. I meant that your claims are opposite to the claims of a famous coach who used to post here. According to him, pros hit on the lower side for more topspin.
travlerajm
Talk Tennis Guru
He would not be the first person to make that mistake due to the counterintuitive nature of the gear effect. The TW Professor does discuss the gear effect correctly in his article about the effect of added mass at 3 and 9 on topspin.
Dartagnan64
G.O.A.T.
And so you'd think golfers would evolve to hit toe shots if they want to hook the ball and heel shots if they want to fade the ball but they don't. If anything they hit closer to the sweetspot than rec golfers in a very tight distribution. Why because off center hits are too unreliable to control. Instead they adapt their swing to produce the desired curves.
That is why I think this is all ridiculous. Nothing good happens from hitting away from the sweetspot. You lose power unpredictably. You affect spin unreliably. You increase racquet deflection and lose directional control. You get too close to the frame leading to framed shots.
Until someone posts an interview of a pro saying that off center hits are a plan not an error, this is all BS in my book.
travlerajm
Talk Tennis Guru
I think this is the correct answer.
Chas Tennis
G.O.A.T.
That issue has to be determined by some careful observations and statistics. I had thought that the ball was being contacted in the lower half of the racket face for the forehand topspin drive(below the racket shaft line extended across the face). There was a longer thread where I looked for impact location and did not see the ball as impacting on average in the bottom half. I did enough so that it looked as if impact was near the centerline, but more observations were needed. ?
240 fps captures one frame every 4.3 ms. Impact is estimated to last about 4 ms +/-. I can say that videoing at 240 fps that I almost always saw one frame of the ball appearing to be on the strings. Not two frames or no frame. I would usually use the fastest shutter speed that the available light would allow 1/40,000 to 1/5000 sec to get small motion blur.
Higher frame rates would be better to catch the timing of the ball and the strings. The camera view should be from the side for best estimate ball contact.
The racket face is closed just before first touch for a forehand topspin drive.
The racket tilts because of the impact, up, if in top half, and down, if in bottom half.
Earlier thread. Many of Toly's great pictures are no longer available.
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If you watch high-speed video, you will see that the racket wobbles after the hit, around the axis of the slightly closed face. The thinking was that if the hit was above center, it would tend to make the racket more open, not keep the same degree of closure.
The real reason is gravity of the (maybe even slightly) falling ball, which adds a downward force on the strings when hit on the center, which causes more deflection on the lower side.
dominikk1985
Legend
Various sweet (& other) spots on a racquet:
Three 'Sweet Spots' on Tennis Rackets, Professor Says
Conventional tennis wisdom is all wrong, says a physics professor who has found that a racket has 3 "sweet spots," not one, and that loose rather than taut strings will yield more cross-court winners.
Rod Cross:
.
You are talking something else, i was referring to below the longitudinal axis of the racket.
SystemicAnomaly
Bionic Poster
That particular post had nothing to do with your posts. It was in support of @5263 statement that a racket has multiple sweetspots. Sureshs had claimed that his assertion was untrue.
My response to your post appeared in #12.
SystemicAnomaly
Bionic Poster
Remove the strings from your racket?
rogerroger917
Hall of Fame
You think? Waiting for my thetan to tell me I'm wrong.
Sent from my SM-G986U using Tapatalk
Shroud
Talk Tennis Guru
FWIW I think my whole racquet is dead. Kevlar/4g at 86/66lbs is pretty dead. Personally that last thing I want is a spot on the racquet that behaves differently.
SystemicAnomaly
Bionic Poster
Yeah, it does seem like an oddball concept, at least for groundstrokes and volleys. But there were one or two coaches on YT or the interwebs who were trying to convince us that is exactly what the pros are doing.
But that said, there is a good reason for hitting high in the stringbed (toward 12 o'clock, the tip) for serves. 1st serves, in particular.
I'm talking about contacting the stringbed up around the dead zone (shown in a previous post in this thread). I don't know if the optimal point is the dead zone itself or if the optimal area is somewhere between that sweetest spot and the dead zone.
Yes, the strings are much less responsive when you contact the ball closer to the frame. But this is believed to be offset by the fact that the higher part of the stringbed (toward the tip) is moving much faster than the lower part of the stringbed when hitting an overhead or a flat serve.
Remember that the racket is pretty much moving thru an arc for serves and overheads. The angular velocity of the racket is the same for all points on the racket. But the linear velocity of a specific point increases as you move further away from the hand holding the racket. That is, the handle right above the hand is moving quite a bit slower (since it does not travel very far) than the very tip of the racket (since it moves a greater distance than any other part of the racket, in the same amount of time).
So, the optimal area for fast flat serves and most overhead smashes, will be somewhere between a the normal sweetspot and the tip of the racket. Some elite tennis players and badminton players take advantage of this and strive to hit higher in the bed. But this is not necessarily true for all elites.
megamind
Legend
thank you 4 sharing the secrets of the drop volley
5263
G.O.A.T.
well read up on the sweet spots and you will know more about them
thanks SystemVarious sweet (& other) spots on a racquet:
Three 'Sweet Spots' on Tennis Rackets, Professor Says
Conventional tennis wisdom is all wrong, says a physics professor who has found that a racket has 3 "sweet spots," not one, and that loose rather than taut strings will yield more cross-court winners.
Rod Cross:
.
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pencilcheck
Hall of Fame
Looks like this again, I will play along since it doesn't hurt.
Yea, it is, most 4.5+ do that all the time, it is something you train specifically. First you need to find the center spot, you specifically practice to not hit there by doing avoidance, to do avoidance training, it is very simple, you run away from the ball.
So the process at a high level is very simple, just run away from the ball and try to hit the ball while running away, that's how you hit off center shot. Whether that shot goes in is another story.
Yea, it is, most 4.5+ do that all the time, it is something you train specifically. First you need to find the center spot, you specifically practice to not hit there by doing avoidance, to do avoidance training, it is very simple, you run away from the ball.
So the process at a high level is very simple, just run away from the ball and try to hit the ball while running away, that's how you hit off center shot. Whether that shot goes in is another story.
Oscar Wenger's book instructs the player to seek to hit the ball just below the center of the racquet. I don't know if people actually do it.
There was also the TWU experiment that indicated a ball hitting 2 inches below the center of the sweet spot generated 53% more spin.
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I am referring to hitting at below center ( toward 6 o'clock) or above center (toward 12 o'clock) with the frame tip pointing to the right fence, strings parallel to the net and thus tip of frame is 3 o'clock.
Right handed player hitting a Forehand.
Note this is opposite of what most people think of 6 and 12 o'clock.
Usually 12 o'clock is the tip of the frame and 6 o'clock is near the throat.
Call it what ever you want, hitting above or below the center line axis which runs from butt to tip of the frame is what I am referring to.
Thanks for your thoughts.
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SystemicAnomaly
Bionic Poster
@paulfr
Does this suggest that different frames, some with built-in perimeter weighting, will produce different spin effects than that of the Prince EXO3 Red (105) racket? What effects will adding lead to various parts of the racket have? What effect will frames with different stiffness patterns or mass distribution have?
Further, will different stringbed patterns, different string types, different string gauges or different string tensions also produce different results?
Interesting. But rather odd, unexpected results when weights (3.5 oz) were added at 3 & 9. Hitting high in the bed (2" above centerline) produced the greatest spin, while hitting low in the bed (2" below center) produce the least, with the added weight. The opposite of the results for the Prince racket used without added perimeter weighting.
Does this suggest that different frames, some with built-in perimeter weighting, will produce different spin effects than that of the Prince EXO3 Red (105) racket? What effects will adding lead to various parts of the racket have? What effect will frames with different stiffness patterns or mass distribution have?
Further, will different stringbed patterns, different string types, different string gauges or different string tensions also produce different results?
Based on that, I've stopped weighting my racquets at 3 and 9!
Interesting indeed
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SystemicAnomaly
Bionic Poster
However, depending on your racket and strings YMMV.
100 g of added weight is quite a bit. The researchers may have gone with a hefty weight addition to minimize racket head torquing or to magnify any effect that might happen with adding perimeter weighting.
Yes, I think they went completely overboard to magnify any effects.
The clips are the relevant paragraphs from Wegner's book, "Play better Tennis in two hours"
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SystemicAnomaly
Bionic Poster
@paulfr
Subsequently, (with the racket more-or-less parallel to the ground), the stringbed was divided into three zones (upper, middle, lower). Data taken from Nadal's racket showed him hitting his FHs in the middle zone about 55% of the time. The remainder of his FHs were hit in the upper and lower zones.
Interestingly tho', a greater percentage was hit in the upper third than in the lower third for his FHs. For BHs, Rafa was hitting in the lower third somewhat more than he was hitting in the upper third. Here is one of the discussion threads from 5 years ago
Unfortunately, some of the data shown in that thread no longer seems to be available. However the discussion makes it fairly clear that pros intentionally hitting a majority of their shots below the centerline appeared to be a myth.
Apparently, Wegner and others had noticed that the pros hit some of their shots low in the stringbed. Their speculation and conclusion about the intention and hitting patterns of elite players was not backed up by the data.
When the stringbed is divided into 5 zones, we see that approx 50% of FH shots were hit in the central zone. The other half were hit in the upper, lower, right and left zones. Here is an image from Jan 2015 (AO). It shows BabolatPlay data from Rafa's racket for his FHs:
Here is the Twitter link for that image:
Some 4-6 years ago, we discussed this very subject, at least, 2 or 3 times. John Yandell (TennisPlayer.net) had chimed in after analyzing countless hours of HD video. IIRC, he had indicated that the top pros he had studied hit the ball above and below the (long-axis) centerline pretty much equally.Yes, I think they went completely overboard to magnify any effects.
The clips are the relevant paragraphs from Wegner's book, "Play better Tennis in two hours"
Sent from my CLT-L09 using Tapatalk
Subsequently, (with the racket more-or-less parallel to the ground), the stringbed was divided into three zones (upper, middle, lower). Data taken from Nadal's racket showed him hitting his FHs in the middle zone about 55% of the time. The remainder of his FHs were hit in the upper and lower zones.
Interestingly tho', a greater percentage was hit in the upper third than in the lower third for his FHs. For BHs, Rafa was hitting in the lower third somewhat more than he was hitting in the upper third. Here is one of the discussion threads from 5 years ago
Unfortunately, some of the data shown in that thread no longer seems to be available. However the discussion makes it fairly clear that pros intentionally hitting a majority of their shots below the centerline appeared to be a myth.
Apparently, Wegner and others had noticed that the pros hit some of their shots low in the stringbed. Their speculation and conclusion about the intention and hitting patterns of elite players was not backed up by the data.
When the stringbed is divided into 5 zones, we see that approx 50% of FH shots were hit in the central zone. The other half were hit in the upper, lower, right and left zones. Here is an image from Jan 2015 (AO). It shows BabolatPlay data from Rafa's racket for his FHs:
Here is the Twitter link for that image:
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golden chicken
Hall of Fame
Amazing they only hit the "sweet spot" about half the time!
did you try to hit with the frame instead of stringbed?
I think I hit it less often.
Very happy when I brake the strings in the sweetspot, but I need to be in good shape for this.
SystemicAnomaly
Bionic Poster
High ball speeds and very high spin rates when the pros hit against each other in matches. If Rafa was hitting against me, he would probably be able to hit the sweetspot a lot more often than 50%.
Shroud
Talk Tennis Guru
That is why you are one of the best posters here. You would even take it easy on Rafa....
SystemicAnomaly
Bionic Poster
Sure, anything to make Rafa look good and improve his BabolatPlay data.
golden chicken
Hall of Fame
I think it would be interesting by TTW standards to see the the breakdown when the stringbed is broken into 5 sections in each direction instead of 3.
But I think it lends credibility to the idea that people (pros included) aim for the middle and hope for the best.
But I think it lends credibility to the idea that people (pros included) aim for the middle and hope for the best.
I saw that thread - I was going to mention, as someone did above that that 49% would be interesting to have broken down further - looking at the data as is would suggest a randomness to the above and below center hits.@paulfr
Some 4-6 years ago, we discussed this very subject, at least, 2 or 3 times. John Yandell (TennisPlayer.net) had chimed in after analyzing countless hours of HD video. IIRC, he had indicated that the top pros he had studied hit the ball above and below the (long-axis) centerline pretty much equally.
Subsequently, (with the racket more-or-less parallel to the ground), the stringbed was divided into three zones (upper, middle, lower). Data taken from Nadal's racket showed him hitting his FHs in the middle zone about 55% of the time. The remainder of his FHs were hit in the upper and lower zones.
Interestingly tho', a greater percentage was hit in the upper third than in the lower third for his FHs. For BHs, Rafa was hitting in the lower third somewhat more than he was hitting in the upper third. Here is one of the discussion threads from 5 years ago
Unfortunately, some of the data shown in that thread no longer seems to be available. However the discussion makes it fairly clear that pros intentionally hitting a majority of their shots below the centerline appeared to be a myth.
Apparently, Wegner and others had noticed that the pros hit some of their shots low in the stringbed. Their speculation and conclusion about the intention and hitting patterns of elite players was not backed up by the data.
When the stringbed is divided into 5 zones, we see that approx 50% of FH shots were hit in the central zone. The other half were hit in the upper, lower, right and left zones. Here is an image from Jan 2015 (AO). It shows BabolatPlay data from Rafa's racket for his FHs:
Here is the Twitter link for that image:
Sent from my CLT-L09 using Tapatalk
SystemicAnomaly
Bionic Poster
What was really telling was that the BabolatPlay data was more-or-less what JY (TP.net) had observed with inspection of hours of HD videos of the top pros.
And the BabolatPlay data referenced in the thread that I linked was from late May of 2015. The other BabolatPlay data (image & link) that I had posted was from 4 months earlier -- from the AO in late Jan. Even tho the data was somewhat different for those 2 days, they were very much in agreement in that they showed pretty much the same trends / tendencies.
