Understanding sidespin on groundstrokes

Discussion in 'Tennis Tips/Instruction' started by tennis_hack, Jul 13, 2013.

  1. tennis_hack

    tennis_hack Banned

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    I think sidespin should not really be intentionally hit - but it is an inevitable part of modern swing production which has aggressive windshield wiper finishes where the racket swing path is somewhat rotational, and will inevitably impart a degree of sidespin.

    It would be nice to summarize how this sidespin works.

    So, if you're a righty playing another righty;

    Hitting cross-court forehands generally causes your forehand to hook inside, bending more towards your opponent's forehand or deuce side than would happen without the sidespin?

    Hitting inside-out (or down-the-line) forehands generally causes your forehand to hook outwards, bending more to your opponent's backhand or ad side than would happen without the sidespin? Here's a video of it (but for a lefty instead of a righty);

    http://www.youtube.com/watch?feature=player_detailpage&v=G2ji6a0p5PM#t=208s

    Hitting cross-court backhands generally causes your backhand to hook inwards, bending more towards your opponent's backhand side or ad side than would happen without the sidespin?

    Hitting inside-out (or down-the-line) backhands generally causes your backhand to hook outwards, bending more towards your opponent's forehand or deuce side than would happen without the sidespin? Here's a video of it;

    http://www.youtube.com/watch?feature=player_detailpage&v=9ddvtzOhjHI#t=160s

    Hitting forehands on the dead run can cause the ball to dramatically hook round to your opponent's forehand or deuce side, and thus can 'banana' round the net post. Here's a video of it (but for a lefty instead of a righty);

    http://www.youtube.com/watch?feature=player_detailpage&v=oWbWzwpddEg#t=26s

    Hitting backhands on the dead run can cause the ball to dramatically hook round to your opponent's backhand or ad side, and thus can 'banana' round the net post? Here's a video of it (but for a lefty instead of a righty);

    http://www.youtube.com/watch?feature=player_detailpage&v=9dDh0nKNdsE#t=600s

    Hitting slice backhands cross-court generally causes the ball to drift outwards into your opponent's forehand or deuce side more than would happen without sidespin? Here's a video of it (but for a lefty instead of a righty);

    http://www.youtube.com/watch?feature=player_detailpage&v=xMMthwtEqD8#t=21s

    Hitting inside out (or down-the-line) slice backhands generally causes the ball to drift outwards into the opponent's forehand or deuce side more than would happen without sidespin? Here's video of it (but for a lefty instead of a righty);

    http://www.youtube.com/watch?feature=player_detailpage&v=oWbWzwpddEg#t=121s





    As you can see by the numerous question marks in my post - I'm no expert, so correct me if I'm wrong. Also, I'd ideally like video examples of everything, so help me out there as well please!
     
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  2. NLBwell

    NLBwell Legend

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    Why not? Sidespin is a very useful weapon at times. Don't leave it out of your arsenal. Every good player should be able to hit whatever amount of sidespin he desires.
     
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  3. Shroud

    Shroud Hall of Fame

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    Its a confusing post i think because there are different types of sidespin. For instance on the forehand, there is the kind done by the windshield wiper forehand, and then there is the running forehand kind that produces the banana type of shot.

    In the first two forehand examples i think you are talking about 2 different kinds of sidespin, otherwise how can the same spin jump 2 different ways just because you hit one crosscourt or down the line? Its the same spin.

    Anyhow none of the video links would work for me so maybe they clear things up.

    agree with nlb, sidespin is a weapon and imho its a core principle of the modern fh
     
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  4. RetroSpin

    RetroSpin Hall of Fame

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    OP is basically right. The modern FH will produce a ball that does not always spin on a horizontal axis. Hence, it curves in the air, like a cut fastball in baseball. It t akes a lot of spin to create that effect however, so most players are not going to produce it. At best, they will get the side hop when it bounces.
     
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  5. tennis_hack

    tennis_hack Banned

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    Hey - I didn't want to over complicate things.

    I would never hit a shot attempting to hit sidespin on it, but I'll realize that hitting some sidespin is inevitable.

    For example, sometimes I try to slice DTL, but then the sidespin takes the ball well wide. Now I know that slicing DTL produces a veer to the deuce court, I'll aim more inside the line for the shot to be effective.

    And, somehow, inside out and dtl forehands do produce the opposite curve to crosscourt forehands. See Bellucci's sick spin on the dtl forehand posted in the OP - curves the opposite direction, and back into the court from being hit wide.

    And someone explain that sidespin on the Gasquet inside out backhand I linked in the OP. Is that usual for inside out backhands to curve towards the deuce tramline?
     
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  6. TimeSpiral

    TimeSpiral Professional

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    No worries. I get it, you don't want to complicate things, but you are talking about physics, lol. I broke it down into the X, Y, and Z axis, because those are the fundamental principles of spin. Once you know those, you can apply them to all the different court positions, swing paths, and shots you want and you'll understand what the ball will do.

    You keep saying you don't want to intentionally create side-spin (Y axis), but a few posters--myself included--are trying to tell you that you're wrong. There are numerous reasons for side-spin. The Gasquet video is a perfect example of spinning the ball away from your opponent.

    The advantage of spinning the ball away from your opponent (or into them!) seems pretty obvious to me.
     
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  7. tennis_hack

    tennis_hack Banned

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    Yeah, but you have so little control of hitting sidespin that you may as well just not really think about it.

    That Gasquet backhand, I'm sure Gasquet was trying to just hit it down the line into Davy's forehand corner, but the outside spin made it spin away from Davydenko and makde the shot even more effective than he intended for it to be.

    Inside out backhands always seem to have this spin, see Federer's point winning backhand here;

    http://www.youtube.com/watch?v=ZKlm2GKZZJ0

    it also spins away from Djokovic's forehand side.
     
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  8. toly

    toly Hall of Fame

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    First of all you should learn something about vectors due to translational and angular velocities are vectors. This is really not big deal.
    Then you can read about any ball’s spin in thread http://tt.tennis-warehouse.com/showthread.php?t=436086
    Good luck. :)
     
    Last edited: Jul 15, 2013
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  9. psv255

    psv255 Professional

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    You're right that a player hitting the ball to a certain spot doesn't think about the amount of sidespin they are applying. They usually visualize a flight path for the ball (or simply aim for a spot on the court) and then try to replicate that with the stroke. Gasquet has already, subconsciously, through hours of practice, taken his shot's sidespin into account and only thinks about the spot he wishes to hit to. If he hits a shot more effectively than he intended, though, he might be upset with it, since one would ideally want full control over the resulting shot.
     
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  10. TimeSpiral

    TimeSpiral Professional

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    Am I getting trolled?
     
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  11. tennis_hack

    tennis_hack Banned

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    You really think Gasquet knew that he was going to put so much sidespin off a deep Davydenko groundstroke that he barely had time to react to that he would pull Davydenko off the court?

    Bear in mind it is more normal to put a lot of sidespin into a topspin shot when you're running. And Gasquet was rooted to the spot.

    I think he was aiming for a good backhand into Davydenko's forehand corner, and the sidespin component gave his shot an unexpected little extra.
     
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  12. TimeSpiral

    TimeSpiral Professional

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    Yes, of course. But who cares about what Gasquet may or may not have been thinking? Can we agree that it's safe to assume that a top-ten ATP star understands the spin he puts on the ball?

    But, I thought the argument was [below]:

    To which I've argued otherwise.
     
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  13. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Both elite and intermediate players intentionally hit with (Y-axis) sidespin all this time. Of course we see it with the slice (sidespin) serve. But is is also common with BHs (especially slice BHs) and FHs. For the FH, check out the bending banana shots intentionally hit by Nadal and Roddick (Youtube has examples for both players).

    For slice BHs, players will sometime hit on the outside of the ball and sometimes on the inside of the ball (see image below). When hitting the outside (labeled YES), the player produces primarily underspin. There may also be a hint of spiral (corkscrew) spin and (vertical-axis) sidespin. When a player intentionally hits/brushes the inside (labeled NO), then both sidespin and backspin are intentionally generated. There may also be a hint of spiral spin in this case (but it is the opposite flavor of spiral than from the the outside brush).


    [​IMG]

    Note that the side hop is due to the presence of spiral (corkscrew) spin, not due to (Y-axis) sidespin. There is a Magnus effect present when the ball has (vertical axis) sidespin. This causes a left/right bending of the trajectory while the ball is in flight. However, this type of spin has absolutely no effect of the direction of the bounce. Let me say that again... sidespin does not cause a ball to hop to the left or the right. Physicist Rod Cross talks about this in his book, Technical Tennis.

    OTOH, there is no Magnus effect due to spiral spin. This type of spin does not cause a trajectory deviation while the ball is in flight. However, when the ball contacts the court, spiral spin will cause to ball to hop to the right or to the left, depending on the flavor of spiral spin. The 2 flavors are CW and CCW (or anti-clockwise). This is the spin that causes the ball to change directions on a Twist (kick) serve.

    (Note that TimeSpiral had indicated that the Z-axis is parallel to the court (or horizontal). We can think of it in that way, but in one respect, it is not quite accurate. The Z-axis is actually in the direction of the flight of the ball. As the ball flies thru the air, the Z-axis changes a bit wrt the court surface. However, I am splitting hairs with this point and this is not really worth much discussion in this thread).
     
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  14. TimeSpiral

    TimeSpiral Professional

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    ^ Yes. Thanks for taking the discussion to the next level.

    Since you corrected me, let me get this out of the way. In my defense, I did say "parallel to the court surface pointing in the general direction of the ball." You're right. Technically my description was incorrect, but I was generalizing, and simplifying. Since we live in a 3D world, the entire XYZ will change orientation during the flight of a tennis ball. I will go back and revise my post (now that I'm allowed to edit my posts!). You'd have to clarify whether or not you're talking about rotation "relative to the world" or "relative to the object". *shrugs* Like you said, splitting hairs.

    I'm going to push back a little on this:
    Of course it does! If you managed to hit a ball with near-pure Z spin, you would see it clearly; the trajectory of the ball bends around in a spiral relative to the Z plane. The amount the Magnus Force affects trajectory is relative to the rotational axis, so if there is less Z spin than say, Y spin, then the Y spin is going to produce the majority of the trajectory changes.

    I'm no physics expert, so it's hard for me to describe in precise ways. Sometimes you can see a great Z Spin pitch in baseball, you can also see Z Spin table tennis serves.

    I'm having trouble explaining this ... In tennis, sometimes you will see an exaggerated parabolic curve relative to the Z plane. The ball is bending with Y spin but also "spiraling around" the Z axis (the straight vector of the direction of the ball). This happens frequently.
     
    Last edited: Jul 16, 2013
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  15. DirtBaller4

    DirtBaller4 Rookie

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    I love hitting a little side spin away from my opponent, especially down the T on the deuce serve!
     
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  16. tennis_hack

    tennis_hack Banned

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    Why do inside backhands have that outside spin that Gasquet's had?

    And why does Bellucci's forehand curve back into the line after being hit wide, even though he hit it standing still?
     
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  17. TimeSpiral

    TimeSpiral Professional

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    You're not thinking about it from the right perspective. Don't think of it in terms of tennis shots just yet: "BH DTL" or "IO BH" or "FH OTR DTL". Try and visualize it like this.

    Disclaimer: I know people will have issues with this visualize technique, but I think it's a fine one. If you have a simpler way to explain it, go for it!


    Imagine the tennis ball is a clock face.
    [​IMG]

    In the following scenarios I'm only describing spin, not pace. Assume a moderate amount of pace is being applied to the ball.

    Pure Topspin (X spin):
    You're striking the ball from 6 to 12. The Magnus Force pushes this ball down, toward the court surface.

    Pure Backspin (X spin):
    You're striking the ball from 12 to 6. The Magnus Force lifts this ball up, away from the court surface.

    Pure Side Spin (Y spin ->):
    You're striking the ball from 3 to 9. The Magnus Force pushes this ball to your right.

    Pure Side Spin (<- Y spin):
    You're striking the ball from 9 to 3. The Magnus Force pushes this ball to your left.

    The first two are easy to visualize with the clock face, because it's 2D. The Z axis is the depth axis, and requires a different perspective in order to understand it.

    Pure Corkscrew Spin (Z spin Clock-wise (CW))

    You're striking the ball at 3 and tracing the right circumference of the ball to 9. This one's harder to describe, but The Magnus Force pushes this ball in a CW spiral around the Z axis. Tracing the ball from 9 to 3 would be the opposite. And because we have gravity, and a court surface, you'll never actually get a spiral, you only get a parabolic curve (technically, all the spins will create a spiral, but in tennis we only get curves).

    Now, because you asked about specific shots ...
    Imagine you're a right handed player, standing at the center hash-mark on the baseline, and you're going to hit a ground stroke over the net. You're aiming at the T of the service box.

    You strike the ball from 3 to 9. The Y spin created by your swing path will create a flat shot that veers into the ad-court. Similarly, if you were to hit a BH in the same scenario from 9 to 3, the Y spin created by your swing path would create a flat shot veering to the deuce court.

    You can carve the ball in any combination of spins you want to produce different effects. To use your examples:

    Gasquet, with his gorgeous BH DTL, probably struck the ball from around 8 to 2, creating a flat shot, with decent pace, veering to his left (away from his opponent). I suppose it's useful to point out now that the clock-face is fixed to the direction of the ball. So he could hit the same exact 8 to 2 swing cross court by changing the direction of the Z axis (changing his aim).

    I didn't watch the Belluci example (they're not marked!). As an exercise, try and figure out his swing path using the clock visualization.

    Hopefully this helps. Grab a bucket, go out there, and experiment with the different spin combinations. It's great fun! If you want to see really exaggerated spin paths, grab a buddy and go play some table tennis. The Magnus Effect works MIRACLES on those little balls ... it's crazy.
     
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  18. Shroud

    Shroud Hall of Fame

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    Ok this all makes sense. But it has been said that hitting cross court produces a different bounce than down the line. If I am hitting a backhand from 8 to 2 and I hit it down the line does it bounce differently than if I hit the same 8 to 2 crosscourt?
     
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  19. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    These are supposed to be a topspin BHs? I cannot imagine how you are brushing from 8 to 2. Are you talkng about at diagonal brush from 8 to 2? Or are you brushing up from an 8 o'clock position and then over toward 2 o'clock? Hard to determine or visualize exactly what you are talking about here.
    .
     
    Last edited: Jul 17, 2013
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  20. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Well, I'm just gonna have to push right back...

    As I stated previously, there is no Magnus effect associated with spiral spin. Not really following your explanation but allow me to back up my own assertion.

    Note that tennis balls, table tennis balls, baseballs and soccer balls pretty much never have spiral spin without the presence of Y-axis and X and axis spins. It has to do with our anatomy and the way we strike or throw a spherical ball. Usually the latter spins components are much greater than the Z-axis component. In tennis, whenever we impart a Y-axis sidespin to the ball, we also impart a spiral spin component. In most cases this Z-axis component is negligible or so slight that we do not notice its effects (on the bounce).

    Consider, if you will, the trajectory of a badminton shuttle or a spiral pass in (American) football. These "balls" usually do possess spiral spin without the presence of X-axis or Y-axis spins. We do not see any trajectory bending (left/right or up/down deviations) with the shuttle or the football unless there is a significant crosswind present. There may be a bit of a wobble with the football but I've never observed this with a good badminton shuttle. The football wobble does not appear to have any significant effect on trajectory.

    Gun barrels are usually "rifled" in order to impart spiral spin to bullets. Arrows are also sometimes designed to fly with spiral spin. Spiral spin is imparted to such projectiles in order to stabilize their trajectories. If this type of spin resulted in trajectory deviations, it would render these projectiles inaccurate. It should be noted that, for very long range ballistics, spiral spin might result in small trajectory errors. However, I do not believe that this has anything at all to do with a Magnus effect and has no bearing on the fluid dynamics of a tennis ball.

    With sidespin and topspin/backspin, the spin axis is perpendicular to the flight direction. However, the spin axis for spiral spin is in the direction of the flight path. It is because of this, that no Magnus effect is produced by spiral spin. Think about it. With the other spin types, one side of the ball is spinning in the direction of the flight of the ball. The other side is spinning in the opposite direction of the flight of the ball. The latter produces a low pressure area on that side of the ball. The first side has a high pressure associated with it. This pressure differential is what causes the Magnus effect (the trajectory deviation). There are no air pressure differentials created by spiral spin, hence there is no Magnus effect.

    Perhaps the following image can aid in visualizing and understanding spins and their associated Magnus effect (F). This can be viewed as a side view for a topspin ball or a top view for a sidespin ball.

    [​IMG]
     
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  21. TimeSpiral

    TimeSpiral Professional

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    For the record, I'm really enjoying this conversation! But I'd like to reiterate my disclaimer--no physics expert here. I'm prepared to be wrong, if I'm wrong.

    I do take issue with your comparison though. You're comparing projectiles, like bullets and American Footballs, specifically designed to be aerodynamic and spin stabilized. And in your own example, you state clearly that Z pin alters the trajectory, by stabilizing it (stabilizing would be an alteration of the flight path). Thanks, Magnus Effect! And thanks gyroscopic precession!

    But we're talking about the Magnus Effect within the context of tennis, which means the projectile is a fuzzy yellow ball (you're welcome, Will), there is a court, and there are variable 3D geomtries you can send the ball on.

    I guess where this issue could get a little fuzzy (no pun intended) is the relativity applied to the shot we're analyzing. Clearly, not every shot with Z spin is going to present Magnus Effects. However, an extreme example: I go for a super BH slice, but I screw up and essentially strike the bottom of the ball. I put virtually zero forward momentum on the ball, effectively making it a drop shot, but the trajectory is a high loop, maybe 20 feet over the net (a terrible drop shot!). The extreme Z spin on the ball is going result in the Magnus Effect curving the trajectory, and as expected, the ball is going to kick dramatically when it hits the court surface.

    From my perspective, the tennis ball has Z spin, but because of the trajectory of the ball--going almost straight up, with very little forward momentum--you could argue that the Z axis has changed to the X axis and the ball has "topspin." (Imagine laying with your back on the court looking up at the ball. It would look as if the ball is moving from left to right but bending with topspin). But my argument is that when talking about spin in tennis, I believe it's proper to remain in the perspective of "relative to the shot maker." Maybe this is where we are disagreeing?

    The example I gave, the super-kicker high-ball drop shot, is an example where the Magnus Effect is clearly acting on a Z spin shot.
     
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  22. TimeSpiral

    TimeSpiral Professional

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    Shoot ... I saw these after writing my response to the physics debate. Sorry!
    This shot would have some topspin on it, but not much. And it's the former. You're brushing diagonally from 8 to 2.

    Velocity, direction (aim), spin, and angle of incidence, determine the bounce of the ball. See figure (1) below.

    Figure (1):
    [​IMG]

    You can hit a CC shot with all sorts of different types of spin and it will bounce off the court differently. Similarly, you can hit DTL and vary the bounce significantly.

    If the two shots are exactly the same, save the only difference being your aim--either CC or DTL--then the bend in flight path and bounce off the court is going to be the same. The observed difference is relative to the court. Let's assume your CC FH has right-handed Y spin on it. It will appear to bend into the returner's FH wing. That same shot aimed DTL will appear to bend away from the returner's BH. Same thing with topspin, or any other type of kick spin. The CC topspin will seemingly kick forward, but because of the CC angle, it is moving away from the forehand wing. The same shot DTL will kick forward through the court towards the baseline, or your opponent's BH.

    What you'll often see is player's altering the Y spin specifically to bend the CC FH out wide, to create a more severe angle. When hitting the FH DTL, or IO, they will often employ the opposite type of Y spin, to bend the ball out wide to the BH.
     
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  23. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Physicist, Rod Cross, had indicated that spiral spin does not produce a Magnus effect. In the TW University page (on this web site), he refers to it as gyrospin. He has this to say about that:

    "Gyrospin. Some players tend to strike the ball slightly towards the side of the ball rather than exactly across the back of the ball, in which case the ball will also spin about a horizontal axis pointing towards the net. That sort of spin is used to throw a gridiron football, but it has no effect on curvature of the ball through the air."

    http://twu.tennis-warehouse.com/learning_center/kickserve.php

    He has much more to say about spiral spin in his book, Technical Tennis. He has written other books on tennis physics as well. One (or 2) of these is a collaboration with physicist, Howard Brody.

    When I have more time, I will go back to post #23 to address the issues/flaws.
    .
     
    Last edited: Jul 17, 2013
    #23
  24. Shroud

    Shroud Hall of Fame

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    What you'll often see is player's altering the Y spin specifically to bend the CC FH out wide, to create a more severe angle. When hitting the FH DTL, or IO, they will often employ the opposite type of Y spin, to bend the ball out wide to the BH.[/QUOTE]

    Now that I can believe. It says that to get your forehand to bounce one way you need one kind of y spin, and to get it to bounce the other you need another kind. That makes perfect sense.

    But what is asserted here is the somehow just by changing the direction WITH THE SAME Y SPIN you can get a different bounce.

    In your example about topspin for sure it will angle to the forehand or backhand but the BOUNCE is the SAME, namely in line with the trajectory.

    A curve ball has the same curve if I throw it to the inside or the outside of home plate or to 3rd base for that matter. To get a different curve I need to throw a totally different pitch (corkscrew IIRC)....
     
    #24
  25. TomT

    TomT Hall of Fame

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    It's also an inevitable part of classical swing production, especially net approach shots, and very effective in f...ing opponents up. The more sidespin the better, I always say. :) If you look at some of my vids you will see that the reason some of my opponents completely miss (not just mishit, but miss, completely) some of my approach shots is because the ball is bouncing rapidly away from them, on both sides, after it hits their side of the court.

    Sidespin is a weapon, as well as something that adds to the esthetic beauty of the game, imho.
     
    Last edited: Jul 17, 2013
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  26. newpball

    newpball Legend

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    I don't believe it.

    From Wikipedia:

    In terms of ball games, top spin is defined as spin about a horizontal axis perpendicular to the direction of travel, where the top surface of the ball is moving forward with the spin. Under the Magnus effect, top spin produces a downward swerve of a moving ball, greater than would be produced by gravity alone, and back spin has the opposite effect, and the ball seems to rise in the air—a phenomenon observed during golf drives from a tee. Likewise side-spin causes swerve to either side as seen during some baseball pitches.

    https://en.wikipedia.org/wiki/Magnus_effect
     
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  27. Cheetah

    Cheetah Hall of Fame

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    side-spin is not spiral-spin.
     
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  28. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    ^^ The spin that we call sidespin is a vertical axis (Y-axis) spin. Spiralspin (aka gyrospin or corkscrew spin) is a Z-axis spin. I clearly made that distinction in a couple of my posts above. Note that X and Y axes are perpendicular to the ball's flight, The Z-axis is in the same direction as the flight of the ball. Huge difference.

    I will answer the other points brought up in post #23 later today or tomorrow.
     
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  29. TimeSpiral

    TimeSpiral Professional

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    I have not read the book, so I cannot comment on that. But I'm not even a scientist and that claim right there seems dubious, but *shrugs*. I'd like to see the data--from an experiment--showing that various tennis shots, struck with Z spin, have no Magnus Effect acting on them.

    Perhaps one day I will read the book. Maybe the data is in there! In my experience, 2nd hand science is almost always misrepresented by laypeople (like you and me--unless you're a scientist!). I try, but even when I think I'm right-on, my science buddies will point out flaws in my thinking.

    Let's be real ... you and I are talking about rotational physics. Hardly a lay topic.

    Science literacy is low in the States (don't know where you're from), and one of the huge problems we have is that: lay people read articles about an experiment (or a conclusion)--sometimes the author has read the study, other times they haven't--the layman then thinks they know what it means, applies it to whatever they're talking about, and then cites the study (by proxy, via the article) as proof. Sometimes this works, and it's part of proper research, but you probably see the issue I'm trying to illustrate. (Upon editing for mntlblok, I notced this as the worst paragraph ever written. *Sighs*)

    I think I see the heart of our disagreement: orientation of spin relative to what? Relative to the ball--as if you're not playing tennis--I can see why Z spin would not affect the trajectory of the ball (in windless conditions), however; in tennis you're always hitting the ball forward, to some degree, over a net, relative to a tennis court. So when thinking about tennis, I feel it's relevant to also look at spin orientations relative to tennis. Maybe that's where we're disagreeing?

    Either way--great conversation! Best I've had on TT yet.

    @Shroud,

    Y spin can affect the bounce, but not in the way you're thinking. When the ball kicks out to some degree other than straight forward, that's caused by Z spin, however; a ball struck with Y spin is often a flat shot. This flattening of the flight path, combined with side spin, causes the ball to skid off the court more than a ball with topspin or backspin would--meaning the angle in which it bounces off the court will be lower. This principle is also why backspin shots have the tendency of "sitting up."
     
    Last edited: Jul 21, 2013
    #29
  30. newpball

    newpball Legend

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    Oh I see.

    <->
     
    #30
  31. MisterP

    MisterP Semi-Pro

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    Ok - there's a lot of splitting hairs going on in this thread. But just to address the first point you make, please see the vid below:

    http://www.youtube.com/watch?v=FG3dHBT_Ci8#t=39s

    Without the side spin Murray gets to the shot and makes Roger play one more ball.
     
    #31
  32. TimeSpiral

    TimeSpiral Professional

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    That drop volley kicks out to Roger's left because of Z spin. There is some side spin on it to, because that's the nature of the shot, but that's not the spin that kicks the ball out.

    He's an extreme example of side spin. It's a table tennis point, and it's the shot they replay in slow motion: http://www.youtube.com/watch?v=9XNhRxTUKq0&NR=1&feature=fvwp
     
    #32
  33. TimeSpiral

    TimeSpiral Professional

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    #33
  34. Shroud

    Shroud Hall of Fame

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    Semi-western backhand, and mostly diagonally 8-2 but there is a windshield wiper finish that comes across at the end not exactly diagonal.
     
    #34
  35. 5263

    5263 G.O.A.T.

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    Point is yes, you should be working some element of diagonal spin on every shot,
    and I don't see how you do that without intention, but I'm sure some can.
    Clearly it is Ok and Imo desirable to be aware of it. :)
     
    #35
  36. Shroud

    Shroud Hall of Fame

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    Yep. Did it naturally on the backhand and now the forehand has improved since I began consciously adding it probably from 4-10.
     
    #36
  37. 5263

    5263 G.O.A.T.

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    helped me to think of it as well, thanks
     
    #37
  38. mntlblok

    mntlblok Professional

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    Spin axes

    So happy to see somebody else (TimeSpiral) going to the trouble of figuring out the spin axes. Have already learnt to enjoy SystemicAnomaly's posts.

    I had also decided that it was no coincidence that, in post #6, that TS got "affect/effect" right. But, alas, I'll have to hope that it was merely a typo in post # 31. :mrgreen: Top *that* for OCD. . .

    Here's some fun I had in an attempt to demonstrate the three axes of spin. http://www.youtube.com/watch?v=B0vEp9B9lRY
     
    #38
  39. TimeSpiral

    TimeSpiral Professional

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    Thanks, Mntlblok.

    I reviewed post #31, and while one paragraph required serious revision (how did I hit publish on that rubbish?!), I couldn't find the hoped-typo you alluded to. Are you suggesting that I incorrectly used affect in the first sentence of the last paragraph?

    Man, that's cool that you went to all the trouble of making an instructional video! The web is so saturated with online Tennis instruction, I've always been too intimidated to do something like that--plus, I'm a mere 4.0. What I have to offer is basics, at best. I don't feel like I have anything new or worthy to offer in that space.

    I did publish one article, but it receives virtually zero traffic, which either means that, (a) it hasn't caught on yet, or (b) it's not a useful article to the people who have read it. Oh well!
     
    #39
  40. mntlblok

    mntlblok Professional

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    "I think I see the heart of our disagreement: orientation of spin relative to what? Relative to the ball--as if you're not playing tennis--I can see why Z spin would not effect the trajectory of the ball (in windless conditions),"

    I'm too old to give a s**t about being intimidated anymore. :mrgreen: Also pretty sure I've studied a bunch of this stuff to a greater degree than most, and don't recall anyone posting a tennis video involving the concept of spiral/gyro/corkscrew spin. Don't think I've seen one that demonstrates my versions of droppers, either. And, I love to argue, and backing up an argument with video seems appropriate. I'm dying to see a video of Lee D's 5.0 volleys. :mrgreen:

    Have spent most of the day finally getting around to uploading videos from dives at the Blue Heron Bridge. Always happy to share what I think is unique stuff. . .

    I also don't get many views of my stuff, but at least it's out there. Well, a couple of exceptions. . .
    http://www.flickr.com/photos/mentalblock/6843532791/ and
    http://www.flickr.com/photos/mentalblock/120519989/
     
    #40
  41. TimeSpiral

    TimeSpiral Professional

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    The rage!

    Can't believe I missed that ... I blame perceptual blindness. During my review, I read the word as "affect." In fact, I'm convinced that you altered reality by observing my post (damn you quantum physics!).

    Perhaps intimidated was the wrong word. Oh well.

    I'm enjoying the discussion on spin. I'm still waiting on what's-his-name (kidding!) to point out my flaws (of which there are many, to be sure).
     
    #41
  42. mntlblok

    mntlblok Professional

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    I've lain awake for hours on many occasions pondering the possibility of the Magnus effect being in play with spiral spin (in spite of what the "Technical Tennis" boys have said on the subject). I've made no progress. You've now made it worse - especially by throwing in the possibility of wind coming into play. I'm *not* inclined, however, to disagree with Dr. Cross - with the possible exception concerning his conclusions about depth with the kick serve. . .

    I also have big problems with the concept of spooky actions at a distance.
     
    Last edited: Jul 22, 2013
    #42
  43. toly

    toly Hall of Fame

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    The rotation of a round ball with gyrospin is absolutely symmetrical relative to the velocity (vector’s direction) of a translational motion of the ball. That’s why, the ball cannot move to the right, to the left, up, or down and create curve. Thus, ball can move in straight direction only, otherwise it contradicts to principles of symmetry. You really cannot say in what direction ball would curve, right?
     
    #43
  44. mntlblok

    mntlblok Professional

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    Oh, and Toly is another guy with whom I'm unlikely to argue - for fear of getting my *** kicked. :mrgreen: I *do* get a kick out of smart folks.
     
    #44

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