Tennis ball spinning-which direction will lead to?

[Skhandelwal]

when tennis ball spins sideways like a hurricane. I have seen that if you spin it a little, it turns one way, when you spin it more, it turns the other way. So here are my questions.
1. Will there come a point as you are inc. angular velocity that it will not change direction anymore?
2. Will there be a point when it would go straight?(that almost happened)

When you spin the table tennis ball upside down(works w/ tennis ball too but clearer to see when you play table tennis) The more you spin it, the more it bounces, but if you keep inc. the spin, it comes to the point when the more you spin, the lower it gets. Well, I was wondering will there come a point when it would bounce higher again?

Thx. for the replies!

 

[Skhandelwal]

Nobody knows? Come on man, if you can't answer all, just answer one.

 

[rcgldr]

Assuming that with enough spin the amount of "lift" is reduced for a moving tennis ball, I doubt that this happens in normal play. However if the ball is moving fast enough, the resulting turblent airflow around the ball will prevent it from curving as much; which is the case in baseball, and probably tennis.

Regarding table tennis, I don't understand your point about how the ball bounces. I assume you mean off the rubber of a table tennis paddle? Again I think the speed of impact is more of an issue. The effect of spin would depend on the elasticity, softness, and thickness of the table tennis rubber sheet used.

 

[xAxis]

I don't understand your questions at all. As far as I know, if you spin tennis ball in right direction, it's path will be curved to the left. The same with soccer ball, if you kick it with "inner felsh" (supposing you kick it with your right foot), it will turn left. The more you spin it, the more it will turn, but always in the same side.
I've seen quite opposit happening with balloon, which I can't explain.
With table tennis ball, did you mean the top spin?

 

[DaveC426913]

Re: the tennis ball, I think he means "off the bounce". i.e. some spin makes it bounce left, more spin makes it bounce right.

Re: the table tennis, I think he's also talking about "off the bounce" but here he's referring to back spin.

So:
Spin a ball horizontally slowly, it bounces left.
Spin a ball horizontally quickly, it bounces right.

No spin on a ball, it bounces high.
Spin a ball vertically, it bounces lower.
Spin a ball vertically quickly, it bounces ... higher?

I think some of those premises are wrong though. I'm merely trying to illuminate.

 

[Clausius2]

However if the ball is moving fast enough, the resulting turblent airflow around the ball will prevent it from curving as much; which is the case in baseball, and probably tennis.
.

Actually in tennis and baseball the Magnus effect is not that explained by means of the Bernoulli equation. The flow around those balls is usually turbulent (Re about 100,000), generating a NEGATIVE Magnus effect, just in the opposite direction.

 

[rcgldr]

Re: the tennis ball, I think he means "off the bounce". i.e. some spin makes it bounce left, more spin makes it bounce right.

In tennis, it's a combination of the path of the ball at impact, and the spin on the ball. Gyroscopic reaction from the court applying a torque to the ball would also be a factor. If you put some right side top spin on a tennis ball, it may be enough to affect the bounce more than the curvature of the path of the ball. Put enough right side top spin on the ball and it curves left, continuing to go left (but a bit less) after impact.

Re: the table tennis, I think he's also talking about "off the bounce" but here he's referring to back spin. No spin on a ball, it bounces high. Spin a ball vertically, it bounces lower. Spin a ball vertically quickly, it bounces ... higher?

Backspin reduces the forwards motion of a table tennis ball, but the only change in height is the lift you get from the back spin on the ball as it travels forwards. Normally, a backspin shot is done low, and by the time the ball bounces, there's not a lot of forwards speed, so there's little lift and no significant change in height, just a slight slowing of the forwards motion (not a lot of friction between table and ball), changing the angle of the bounce. A top spin ball can be fast or slow (bubble loop), and the ball increases it's forwards speed after the bounce. The trajectory of the ball just before it bounces can affect the height. A top spin shot made close to the table has a tendency to bounce low and stay low because of the higher speed and more horizontal trajectory. A top spin shot from further away can result in the ball curving downwards hard enough to change the path at the point it bounces, so that it bounces up higher than expected.

Here's a short clip of the final points of a table tennis match, you can see a significant curve in the top side spin shot, and no unexpected reaction from back-spin bounces.

tt2.wmv

 

[DaveC426913]

...but the only change in height is the lift you get from the back spin on the ball as it travels forwards. Normally, a backspin shot is done low, and by the time the ball bounces, there's not a lot of forwards speed, so there's little lift and no significant change in height, just a slight slowing of the forwards motion (not a lot of friction between table and ball)...

I wonder if the height he thinks he's gaining from a backspin shot has more to do with a misperception.

A backspun ball, with less forward motion, will bounce more times, simply because it's not traveling down the table as far before it either leaves the table or gets returned. This is in contrast to a fast ball, which might only bounce once.

What I'm suggesting is that the experience of "hey, that bounced three times on the table" is getting mistranslated to "hey that bounced higher".

 

[WhyIsItSo]

Having played a little table tennis in my day, I might add a little of my perspective to the discussion.

First, I think some of the original "observational" behavior is mildly misinterpreted.

For example, if you return the ball with a small forward speed, and some backspin, the ball will "float" a little (travel further than expected before dropping to the table). If you hit it with the same forward speed, but a lot of backspin, it will "float" further, and land rather softly - with little bounce. It will also be moving forward with much reduced speed. Very useful technique to drop the ball just over the net when your opponent is standing back from the table. Point is, the more back spin you put on the ball for a given forward speed, the longer it "floats" and the softer it falls until you reach a point where it has little or no forward speed but still has a lot of backspin. Now the ball actually drops more abruptly and may even bounce backwards due to the spin.

Those who can provide explanations of the aerodynamics involved can give us the details of what's going on, but I know just enough to realize the "floating" of the ball requires forward speed.

I believe that the dynamics involved are at the core of the OP observations and questions, and similar issues are affecting the balls behavior for top-spin, and side-spin.

 

[Skhandelwal]

Oh my god, you guys got it all wrong, here let me try again. You guys were right about the first one, I am talking about if you spin a ball little, it goes to the left, if you spin it more, it goes to the right. Remember, I didn't say I do the w/ the racket, I said I do it w/ the ball. I play cricket, in which I spin the ball w/ my hand.

About the other kind of spin, I am going to be extremely specefic this time b/c I tried to be really specific last time.

While playing table tennis, w/ a tacky rubber, slow blade, the ball tends to spin more. Table tennis is the fastest body moving and most ball revolving game in the world.(speed as much as 60 miles per hour and revolution as much as thousands/min.) Now, I think what I am about to tell you will be more BELIEVABLE

While playing table tennis, when a ball comes straight at me w/ virtually no spin, my hand motion goes from low to high.(not backspin)-topspin. Here is a page on what it is: http://tabletennis.about.com/od/spin/ss/spinworkcreate_2.htm\
And here is a slide show clip: http://tabletennis.about.com/od/basicstrokes/ss/fhloopvspush_5.htm

Ok, now since we have our ground clear, let's move on to what is going on. When I topspin a little, the ball bounces more, when I topspin more, it bounces even more, but when I topspin even more, it starts getting low(lower than it would when it would bounce normally, and faster), and when I topspin more, it gets lower(and faster). But fastness is a common theme(scaler)

If you play table tennis then please understand that normal people can't get the ball lower b/c it is a really advance(state level) technique.

Note: I am not concerned about the curve the ball takes in the air, and there is absolutely no side spin(negligable maybe if some)

My question is, if I continue to topspin, would the ball ever bounce higher again?(as it started to bounce lower the more I spin) And if the answer is no then how low can it get? Can it get so low that ball will immediately bounce again after its first bounce? So inorder to pick it, I have to touch the ball right after the moment of impact? B/c that effect is normally accompanied by chop.

Sorry, I didn't have any clips or explanation of this from other site, but hopefully, this is specific enough.

 

[WhyIsItSo]

Ok, now since we have our ground clear, let's move on to what is going on. When I topspin a little, the ball bounces more, when I topspin more, it bounces even more, but when I topspin even more, it starts getting low(lower than it would when it would bounce normally, and faster), and when I topspin more, it gets lower(and faster). But fastness is a common theme(scaler)
<snip>
My question is, if I continue to topspin, would the ball ever bounce higher again?(as it started to bounce lower the more I spin) And if the answer is no then how low can it get? Can it get so low that ball will immediately bounce again after its first bounce? So inorder to pick it, I have to touch the ball right after the moment of impact? B/c that effect is normally accompanied by chop.

I think you can answer your own question.

You know that topspin pushes the ball downwards; observation tells you this is so even without understanding the aerodynamics.

When you put massive amounts of topspin on the ball, when it bounces this topspin fights really hard against the upward momentum from the bounce, rapidly curving the ball downwards again.

I would hazard to say that you have probably hit the ball pretty darn fast in this instance. This can also have an effect on your perception of the ball's travel. I've watched some high-level games, and it is pretty darn hard to keep your eye on the ball all the time because it moves so fast. It is really by anticipation and experience that you manage to keep it in view at all. But that is conjecture.

The massive topspin rapidly overcoming the ball's upward motion due to bouncing is really the answer, and should tell you that extrapolating this out suggests there will always be some bounce, it will just be reversed so fast that you won't see it.

Perhaps at some inhuman rate of rotation, something odd might happen (assuming the ball doesn't disintegrate *lol*), but I'll leave that for the "real" physicists to explain to you. I don't have any idea about that.

 

[rcgldr]

I am talking about if you spin a ball little, it goes to the left, if you spin it more, it goes to the right. Remember, I didn't say I do the w/ the racket, I said I do it w/ the ball. I play cricket, in which I spin the ball w/ my hand.

Well cricket balls have an unusual design. Here's a link about them and magnus effect:

http://www.geocities.com/k_achutarao/MAGNUS/magnus.html

While playing table tennis, w/ a tacky rubber, slow blade, the ball tends to spin more.

Tacky and elastic (bouncy), just tacky doesn't spin the ball as fast as tacky and elastic, for example, Tackiness Chop versus Catalpult or Mark V. Blade speed doesn't matter much on a top spin / loop shot, since the idea is to graze the ball rather than make very solid contact with it.

When a ball comes straight at me w/ virtually no spin, my hand motion goes from low to high ... topspin.

and the racket is "closed", angled forwards, (else the ball would leave the racket at a very high angle, way above the table).

Ok, now since we have our ground clear, let's move on to what is going on. When I topspin a little, the ball bounces more, when I topspin more, it bounces even more, but when I topspin even more, it starts getting low (lower than it would when it would bounce normally, and faster). Note: I am not concerned about the curve the ball takes in the air, and there is absolutely no side spin(negligable maybe if some)

My question is, if I continue to topspin, would the ball ever bounce higher again?(as it started to bounce lower the more I spin) And if the answer is no then how low can it get? Can it get so low that ball will immediately bounce again after its first bounce?

As I mentioned before, it is a combination of the top spin, speed, and the direction (angle) the ball is moving when it contacts the table. Some combinations of spin, forward speed, and the maximum height of the ball above the table cause the ball to curve downwards at a steep angle, and the result is a higher bounce. The lowest bounce height occurs when the ball is struck from close range, say from above the table as opposed to behind it, so that there is little distance or time for the ball to curve. It's called a loop drive shot, the stroke motion and the racket angle are almost horizontal, and the ball path is very near horizontal, just missing the net, hitting the table at a shallow angle, and the top spin causing the ball to bounce off shallower still and curve downwards.

Regarding the limits, I had experience with a Stiga robot (back in 1972). This machine is similar to a baseball pitching machine, with two spinning wheels running independently to propel a table tennis ball. The machine can be set to generate a lot of spin and speed. With the machine and in real life, I've never seen a high speed ball that would bounce twice on the table. Stiga doesn't appear to make such a robot anymore, but Butterfly makes a similar one (two spinning wheels):

butterfly robot htm

I have seen many cases, like a looper versus a chopper, hitting the ball so that the chopper can't back up very fall as the ball curves downwards towards the floor forcing the chopper to return the ball from down low, or from closer into the table (neither of which choppers like to do). The guy in the video clip from above, Jan Ove Waldner, ranked number one back in the 1990's and in the top ten for over twenty years (still in top ten as of last year), was probably the best player against choppers, (also considered the best all around player ever). Do a web search and you shot find a lot of hits. Here's that clip again:

tt2.wmv

 

[Skhandelwal]

Actually the best spin occurs when the speed is least and the racket has no forward motion but just from down to up. As it barely touches the ball. The faster you swing it from up to down, the greater it spins. As in the motion, your hand speed doesn't increase the speed of hte ball(may be a little), it rather increases the spin. What rating are you guys in table tennis btw?

 

[rcgldr]

In my experience, the most spin occurs when the ball has a lot of backspin before it is struck. In order to strike a heavy backspin ball by grazing it on the upper back (almost on the top) side of the ball, a loop drive shot, the ball needs to be struck soon after the bounce, while the ball is still moving upwards. As I mentioned before, the stroke motion and blade angle are almost horizontal. This generates a lot of top spin on the ball, and requires a very large amount of blade speed at the moment of contact. The timing requires precise anticipation, since to generate a lot of blade speed requires a lot of back swing followed by a lot of forward swing on the stroke in order to achieve a high rate of blade speed at the moment of contact, and this has to be timed so the contact occurs while the ball is still moving upwards, and into the path of a closed blade which sweeps a narrow area in the path of the stroke.

Personally, I haven't played much in years. I only played in two tournaments when back when I first started, winning a couple of lower rated events on my second tournament. Based on club competition, the best I got was about 1850 USA rating, and this would be a couple hundred points lower on a world rating system. One of the top 4 USA players lived nearby though (this was back in the late 1970's), and I saw his matches, and occasionally practiced with him. We also had a coach from China visit for about 2 months in the early 1980's and this helped me improve to my best level (the 1850 level as mentioned). Due to a shoulder injury, I quit playing for a while, and after it healed, the place I played at shutdown, and I was unwilling to commute 45 minutes to an hour each way to go to the other active places for table tennis.

 

[rcgldr]

Actually the best spin occurs when the speed is least and the racket has no forward motion but just from down to up.

I editted another video, including normal and slow speed views. The first clip shows the more vertical stroke motion type loop, where there isn't a lot of forward speed, the remaining clips show the loop drive where the stroke motion is more horizontal and uses a lot more blade speed, and both the speed and the spin are much faster with the loop drive. The advantage of this shot is that since the motion is near horizontal, it can be done above the table, while the near vertical stroke can only be done from behind the table. In order to be able to use more blade speed on the more vertical motion, you have to wait for the ball to be moving downwards significantly so the ball won't end up going too high. The near horizontal motion doesn't have any limitations, other than the skill level of the player, and as noted, the ball has to be struck while it's still moving upwards from the bounce off the table. If a player waits until the ball reaches it's peak, there won't be enough contact for the near horizontal stroke and blade angle to work, the blade will have to be opened up, which will increase the speed, but it's a lower percentage shot.

Note, there's no sound on this video:

tt3.wmv

 

[Skhandelwal]

I use both shots and tons more. Depending no the ball, every ball has its own kind of shot to hit. I am not like one of thsoe players who master in one kind of shot. I got varities, tons of it. Btw, I was wondering, scientifically, when I loop the ball just vertically, and when I loop it horizontally. Which one would spin more and why?

I know that we aren't agreeing on spin more but if you could explain to me scientifically, what happens that makes the ball spin more, it might be a bit more convincing.

Also, nobody answered my first question. If I spin a tennis ball sideways by my fingers, like a hurricane, when I spin it a little, it goes to the left, when I do it more, it goes to the right.(I never was talking about cricket ball, I am talking about playing cricket w/ a tennis ball) I was just wondering if there is an exact spin I can do in which ball will rotate but instead of going either left or right, it will go straight! B/c that will be very deceiving.

 

[rcgldr]

I was wondering, scientifically, when I loop the ball just vertically, and when I loop it horizontally. Which one would spin more and why?

When you change or increase the spin on the ball, it causes the ball to also move in the direction of the stroke, because of the resistance to the change in angular momentum, and the fact that the contact is made in the direction of the stroke.

Assuming that a player is trying impart a path that keeps the ball reasonably close to the net as it crosses over the net (as opposed to very high lob), a vertical stroke motion's speed is limited by the amount of spin on the ball before contact (backspin would allow for more blade speed) and it's downward component of velocity before contact (more downwards speed would allow for more blade speed). Bottom line a vertical motion is limited because too much blade speed will result in the ball moving upwards too much (too high an angle). To further increase the spin without the ball moving upwards as much, you need to adjust the angle to be more forwards. This will increase both spin and speed though. The near vertical motion will produce a high spin, low speed shot if that is the goal.

Most of the time I see players using near vertical motion is when the player is back, or the ball is dropping downward before contact, or there's a lot of backspin on the ball. When the player is spinning while near the table, the motion is more forwards, probably ranging between 45 degrees to near 80 degrees from vertical.

 

[Skhandelwal]

hmm strange, for me, the ball goes the slowest, and spinniest when the motion goes from down to up b/c that way, I don't focus on speed as much as spin. When I loop more forward, speed increases more and spin decreases. Btw, what kind of shot are you talking about, where you barely touch the ball(like brushing it) or where you spin the ball by applying more force on it?

 

[rcgldr]

hmm strange, for me, the ball goes the slowest, and spinniest when the motion goes from down to up b/c that way, I don't focus on speed as much as spin. When I loop more forward, speed increases more and spin decreases. Btw, what kind of shot are you talking about, where you barely touch the ball(like brushing it) or where you spin the ball by applying more force on it?

Brushing the ball, although some increase in force won't decrease the spin. I learned this from the Chinese team coach when he visited Southern California for a 2 month clinic, that you can graze the ball too thin, and that a slightly more open racket will produce more spin due to better contact.

Still, the blade angle versus the stroke angle determines how much you "brush the ball", and this can be done with any stroke angle. I've done my share of near horizontal loop drive shots on short balls, sometimes having to run around the side of the table to position for the shot on a really short ball, as the table blocks the path for anything else. This happens more in doubles or against a chopper that doesn't place the ball deep enough.

On my forward motion loops, both spin and speed increase, but speed increases more, so the ratio of spin to speed is less. Take a good look at those videos again. On those loop drive / loop kill shots the blade angle is near horizontal at contact, I'd call that brushing the ball. In spite of the speed, there's a significant downwards curve in the balls path after contact.

If you look at that first sequence in the tt3.wmv, the ball has backspin, it's dropping and struck from well below the table, so a near vertical motion is used. Here is a link to videos of old events: http://tt.mainstreet.net/HungaryChina1981 , the first video shows the off the floor near vertical (and some sideways) motion, but most of them are more like loop drive shots with more forwards motion. This was first time in recent history that the Chinese team got beat. It was almost 10 years later before Sweeden accomplished the same thing (Pearson and Waldner being the top two players on the team, Waldner going on to dominate Table Tennis for a few years, although a few other players, including Pearson were rated # 1 on and off during Waldner's "reign".

Part of this depends on the type of table tennis rubber you're using. Mark V for example, is very elastic, both in bounce and in reversal of spin, and with Mark V and similar rubber sheets, some forwards motion is going to give you more spin than a vertical motion, especially if you're countering a loop with another loop (when one or both players are back from table). Currently, I have Stiga Innova Premium, a more controllable and lighter rubber than Mark V, but with similar speed and spin response, however, my company closed it's gym quite a while ago, so there's no table anymore, and the closest club is inconvenient, too far and only weekends (family time).

Personally and from watching modern top level players, the near vertical loop motion is normally done in special circumstances as I mentioned before (backspin, dropping ball, below table level).

For those not familiar with the amount of friction and elasticity of table tennis rubber, I made a short video. In the second part, I reverse the spin back and forth, striking the ball with a fairly slow motion, but there's enough change in momentum from spin reversal that the ball moves near vertical, inspite of a steep racket angle (about 45 degrees or more from horizontal). Imagine the effect with a lot of blade speed instead of just the small motion I use in the video.

ttstick.wmv

 

[Skhandelwal]

If you take the blade upside down( ball totally facing the floor) w/ a tacky rubber like hurricane, the ball will still stick, for long. Btw, where did you get that first clip from? tt3.wmv?

While looping, do you think concave spins more? Convex? or straight? I know this depends on weather you are using tacky rubber or not but let's discuss both.

I would pick concave on both of them. What do you think?

 

[rcgldr]

Where did you get that first clip from? tt3.wmv?

It's from the 1997 World Championship, individual (not team) event. I think that was the first year Samsonov played really well, he was seeded #4, and beat several of the top Chinese Players. Waldner was seeded #2 (I think that Kong Linghui was seeded #1). In the individual (not team) event, Waldner never lost a single game in the tournament, although he almost did, being down 18-20 against Gatien before coming back and winning that game. Kong Linghui had trouble with Samsonov's very high toss serves, but Waldner, knowing these serves were generally going to be long, began running around and looping hard on these serves. In the second game, Samsonov gave up on the super high toss serves and served more conventionally, but Waldner's overall game was just better and won. Waldner had more trouble against Yan Sen, being down 14-7, but went on a streak to catch up at 16-16, then won that game and the next two.

I think that there were video tapes you could buy, from ReflexSports, of the 44th World Championships. I don't know if these are still around. There should be some table tennis site that has videos for sale or download.

A few things have changed since then. The ball is bigger, 40mm instead of 38mm. A game is now 11 points instead of 21 points, with server changing every 2 points instead of every 5, and a match is best 4 of 7 instead of best 3 of 5 (fewer points per match now). The rules state that no part of a players body or arm can be in front of the point of contact on a serve, so a player can no longer use his arm or body to "hide" the view at the time of contact when serving.

While looping, do you think concave spins more? Convex? or straight? I know this depends on weather you are using tacky rubber or not but let's discuss both.

Straight is the fastest (kill shots), but a concave motion provides a bigger margin for error, and is used more often, especially top spin shots. Looking at Walder, he usually does concave, but sometimes does convex on short strokes at the table, and some really bizarre stroke motions, like blocking side spin loops by holding the paddle sideways (top side of paddle aimed forwards at an angle), and just poking it forwards.

I use Waldner as an example, because most top players considered Waldner's game to have no weaknesses. Considering China was trying specifically to beat him from 1989 to 1997, with few successes, bears this out. He didn't have the strongest loop, fastest kill shot, but he could out counter hit / counter loop just about any player during his prime years, and he could adjust his game quickly when facing a new opponent, adjusting to serves, or weird styles from other players. As I mentioned before, this was most evident in how he dealt with choppers. The first game might be close, but by the 3rd game he'd win by 8 or 9 points (21-12). It was during this period that China accepted the fact that players had to be able to rally well, and not just count on serve and kill to win games, because the service returns were getting better. I'm not sure if this was because of the "gluing" practices that may have started around that time, although some claim that the Hungarians where "re-gluing" back in the 1981 tournament.

The other change is the lack of pen-hold players. The shake hands style allows for a more powerful backhand shot, especially on service returns, although some pen-hold players now use the back side of the paddle for backhand loops, and service returns. The issue is that the traditional pen-hold style requires the player to move around much more and quicker, so the "life-span" of a pen-hold player is shorter than a shake-hands style. In recent years, there are maybe 2 or 3 pen-hold type players at anyone time in the top ten rankings.

 

[Skhandelwal]

Ok, first of all, you don't need to tell me about change or rules, I may be 17 but my strenght is 2000,(b/c I beat 1900 players all the time and have trouble beating 2000's) Am unrated. Second, even though, waldner is considered the greatest player ever, it is b/c of his achievements, not his style, players like Timo Boll are known to have almost no weaknesses. One player I know who does convex most of the times is Wang Liqin and is #1 right now. about penhold, their breed is dyieng, the people he used it most, China, look at them, only old playes are using it, all the new players are coming up w/ shakehand. Btw, you still havn't picked one, which one spins more? Concave, convex or straight loop?(considering the fact that there are 2 types of loops, low to high and back to forward, let's discuss both, including that their are two types or rubber, tacky and nontacky, tell me which kind of rubber are you basing your opinion on.

I still go w/ convex w/ all the combinations.

 

[rcgldr]

you don't need to tell me about change or rules, I may be 17

I only mentioned this because the serve methods you see in the videos are illegal now, and there are only 11 points per game. I don't remember if the clips I have displayed the scores. A new player might wonder about what was going on, which is why I included that comment; just to explain the videos.

Even though Waldner is considered the greatest player ever, it is b/c of his achievements, not his style.

But his style and adaptability is what brought about those acheivements. I mentioned him because he has a very wide variety of shots, and he was the player I focused on in the video clips.

Player who does convex most of the times is Wang Liqin and is #1 right now. Which one spins more? Concave, convex or straight loop?

I mentioned this before, blade speed is fastest with a straight line stroke, or nearly straight line stroke: whatever path is the most natural for maximum blade speed for the player, using a combination of leg motion (forwards and upwards), body twist, shoulder, elbow, and wrist all timed to provide maximum blade speed at the point of contact. However, I rarely see table tennis players using maximum effort for maximum blade speed; the actual blade speed is less, mabye 80% to 90% of the maximum possible for a player (similar to a pitcher, if the players used maximum effort all the time, they would hurt their joints).

So the real question is what motion provides the most margin for error. The error can be timing related, or mis-estimation of spin or speed on the ball. In order to react quicker for positioning, a stroke motion that allows for a wider range of player to contact point position is another criteria to consider.

On a loop shot with a large backswing, it would seem that the biggest variable would be where the contact is made in the stroke, and that a player might want to use a very similar motion for a range of contact points within his stroke. In this case, a concave motion makes more sense. The player adjusts the backswing based on the estimated spin and speed of the ball, and how much blade speed the player estimates he will generate at contact. If the ball is contacted lower in the stroke, there's more upwards motion, to raise the ball more from the lower position, and if the ball is contacted higher in the stroke, there's less upwards motion and the ball is raised less (or not at all) from the higher striking point.

If the amount of spin is unknown, a convex motion might provide more margin for error. If the ball has more backspin or less top spin than estimated, it moves forwards less than anticipated, and with a convex motion, the contact is made later in the stroke with more upwards motion, compensating for the higher amount of backspin or lower amount of topspin. If there's less backspin or more topspin then estimated, then the ball moves forward more than anticipated, and the ball is contacted earlier in the stroke, with less upwards motions, compensating for the lower amount of backspin more the higher amount of backspin. I would think this would apply more to a short ball than a long one off the table.

I've talked about this very thing with a 2250 player that plays 2400+ players all the time, and there's no clear answer, but these are players and not coaches. I've found quite often that even very good players don't often understand the aspects of their own play, but any weaknesses in their play only shows up when playing certain other players, and the players may not even be aware of a flaw in their methods.

 

[Skhandelwal]

aah, I guess i'll have to experiment for that answer. What is your rating btw? Do you use one side pip out?

 

[rcgldr]

What is your rating btw? Do you use one side pip out?

At my best I was probably near 1800-1850. Having practiced with a 2450 player (#4 in the USA), I was good at countering, blocking loops, and at forehand looping against both top spin and back spin. However my backhand wasn't that strong, and I never learned how to flat hit against backspin shots, or to put away easy balls (as the 2450 player always alway hitting real nice consistent loop shots or counter hits when we practice. This player once hit over 5000 counter hits in a row at a demonstration (the other player misses didn't count), and well over 100 loops in row). This was back when I was a 1600-1700 player (rating after the 2nd of the only two tournmanents I played was 1694 after winning two events, and beating some 1700 players). I reached the 1800-1850 level during a time when a Chinese coach held a clinic for two months and I was able to practice / play more than just 1 or 2 days a week. It was a club rating from club tournaments though, using USTTA ratings, but not an official USTTA event. There was a good player (2250) at a previous company, but they closed the gym over a year ago, and I've given up. The nearest club only plays on the weekends (a bad time for me), and the other clubs are too far to justify the cost in gas or time (so now I just workout with weights).

There is a close senior place with some descent players to play on Friday nights that I might start up with again, but I wish it was more than just 1 day a week, and that my wife would want to go with me (she did go to another club, but there were a couple of other women players at her level, that she could play and chat with).

On the paddle, I play standard USA style, inverted on both sides, thicker sponge on the forehand. I eventually improved my backhand and started working on backhand loops when I last played. The main reason I like inverted on both sides is so I can block loop shots at the table, as both Mark V and Stiga Innova Premium reverse the spin well enough that I get enough top spin with virtually no raquet motiont for the ball to curve back downwards onto the table at a descent rate of speed. Most of the time when I beat 1800 level players, it was because I could block their at the table loops fast enough that they couldn't loop again, and they were too dumb or stubborn to realize that they either needed to back up or counter instead of trying to loop everything. On the other hand, if they had just tried chopping everything, I probably would have had a lot of trouble, but most of the choppers I played were only 1600 players (and it was a struggle to have to loop 5 or 6 times in row for every point because I couldn't flat hit againt even a weak backspin shot until later, with Mark V, or Inovva, the rubber has a tendency to reverse the spin, so it has a tendency to rervese backspin with backspin unless you get a descent top spin motion along with the hit). There was one long pips out player that I used to have to loop against, but during this time I finally got descent enough at flat hitting against no spin balls that I was able to win without spending a lot of energy.

 

[Skhandelwal]

I play 2 days a week, are you in ohio? If you come in this state some time if you aren't, may be we can play together? If you like to travel to tourneys, I could invite you to my tournament!(well I am no admin but let's just say I am on the inside)

 

[rcgldr]

I play 2 days a week, are you in ohio? If you come in this state some time if you aren't, may be we can play together? If you like to travel to tourneys, I could invite you to my tournament!(well I am no admin but let's just say I am on the inside)

Southern California here. It's been months since I last played. As mentioned, I might play at the senior center on Friday nights if they still allow guest players (those older still out of shape guys like to give us in shape but out of practice players fits). I'm switching jobs, and not sure of the hours I'll be working at the new place. If it works out that there's another place I can play / practice, then I might start playing again. I've only played in two sanctioned tournaments, and that was ages ago (1977) when I first started. Actually I left the first tourney (1976) early as my wife called with some home emergency. so I didn't get a rating from the 2 or 3 matches I played. The second was a two star event, and it was all day long for my events because of the number of players, and plus I entered two singles (under 1600 (won that one), under 1800, won 3 matches) and one doubles (under 3400, 2nd place in that one, my fault, it was the last event, and I didn't have the energy left to move around and loop, which was my normals double techique since my partner was good at placing backspin shots, usually resulting in me getting a nice long backspin shot to loop against, plus I could block loops for the few that looped, but this was a case of me not running around or chasing down backspin shots to loop them).

I felt bad for my partner, because if I hadn't entered the under 1800 event, it would have been 4 less matches I played, and I would have had more energy for the doubles match. One of those under 1800 matches was against a chopper, and since I was an unrated (estimated 1400) player, and this guy a 1750 player, they put us on a bad table with bad lighting, and it took a lot of effort and looping to win this match (lost the first game, started to acclimate to the table (low bounces) and lighting half-way through the second game and won 21-18, won the last one easily, as the guy kept chopping long and slow allowing me to run around and loop, assuming that my loops were just a fluke inspite of the fact that the majority of my poitns were from looping 5 or 6 times in row (it's always a lot of work when you don't have a good flat hit shot). The guy could counter normally as that's all he did during the warm-up, but never during the game. On the last game, I did get a bit smarter taking advantage of the poor lighting, by moving the paddle upwards then downwards so that what appeared to be a backspin serve was really a no spin or top spin serve, then I started pushing using the same motion. It was a cheesy tactic, that wouldn't normally fool a 1700 player, but with the bad lighting I thought it might work and it did, so I got in a few loop killl shots instead of having to loop a bunch of times for points. Still by the time I lost the 4th match (1780 normal player), I was tired and still had two doubles matches to play, but I ended up with a 1694 rating, an almost 300 point increase from my estimated 1400 rating.

To this day I've never really been that good flat hitting against backspin, something I'll start practicing if I get a chance to play the old geezers again. (I'm 54 years old, so geezers is relative, you only have to be 55 or older to be a member there).

 

[Skhandelwal]

I know how to hit a flat shot on a loop but I find looping more fun, when a person is chopping and you are looping, it becomes like an art. I like it. Btw, to hit straight on chops, imagine that you are trying to hit from the upper side of the racker(which is impossible technically), but when you will hit the ball then,(remember for this, the racket must be closed and flat), it will have tons of forward spin.(not as much as loop though, but then again, unpredictable.(if it would be, your opponent wouldn't get as much time to react)

 

[pingpongpaddy]

This is a classic case of
lifting drive
versus
Sinking drive!
Best demonstrated against chop
In lifting drive the ball is brushed vertically and has a high arc and therefore kicks high
In sinking drive the ball is brushed more forward over the top and so tends to dive toward the floor.
The difference in bounce height mainly relates to the height of the arc and thus the distance ball has to fall to the table surface