so, it's not pronation after all

Discussion in 'Tennis Tips/Instruction' started by luvforty, Feb 28, 2013.

  1. luvforty

    luvforty Banned

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    #1
  2. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Don't agree. Both ISR and forearm pronation are involved.


    .
     
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  3. luvforty

    luvforty Banned

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    I understand... but pronation is just a by-product?

    seems many are teaching the wrong thing? such as swing edge up karate style then pronate to square up the racket face..... that's a wrong picture to paint to the students.
     
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  4. Relinquis

    Relinquis Hall of Fame

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    luvforty,

    well.. you've shown us what you think is the wrong way of describing it, what is the right way?
     
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  5. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    A byproduct of what? Supination? Certainly not ISR (alone).

    Why do you believe that it is wrong? Seems that would work for many students (but perhaps not all).
    .
     
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  6. Mahboob Khan

    Mahboob Khan Hall of Fame

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    The end result is that the pronation of wrist-forearm (if using continental grip) does occur, and it may occur on many forehands (using Eastern and semi-western grips).
     
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  7. luvforty

    luvforty Banned

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    SA - lets say we take ISR out of the picture... take a normal serving stance, but instead of having the right elbow in-line with the shoulder line (in which case ISR will help in RHS)..... we stick the right elbow forward, 90 degrees to the shoulder line..... so ISR would hit the ball straight to the left fence, therefore it's will not help on the RHS if we want to serve into the normal target.

    now, relying on pronation alone, meaning that you drop the racket to back scratch, swing edge on to chop at the ball, and pronate to square up the face.

    how do you generate speed in that scenario? there is not much there. or am I missing something? but this is how a lot of teachers explain the serve - edge on and pronate to hi-five.

    http://www.youtube.com/watch?v=InYd8IrFnkU

    from the trophy position onwards, seems the racket is just like a door opening and shutting, there is very little to none of that chop and pronate stuff.... in other words, I don't think Fed has 'edge on' in mind at all.... seems to me from trophy to impact, his strings are always facing the ball.

    MK - sorry i was talking about the serve, not the FH.
     
    Last edited: Mar 1, 2013
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  8. luvforty

    luvforty Banned

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  9. arche3

    arche3 Banned

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    Uh no... from the start of the up of the racket the edge is on? Its slow mo and clearly its on edge as it starts up from trophy. Its not pan cake from trophy lol.

    Are you formely know as dozu? :rolleyes:
     
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  10. Moz

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    Agree, I thought that looked pretty clear from the video.
     
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  11. arche3

    arche3 Banned

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    Its also like 3000 frames per second john yandel jesus video so how can luv40 possibly not see it?
     
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  12. Chas Tennis

    Chas Tennis Hall of Fame

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    Many of the points that you are discussing must show clearly in this high speed video.

    High speed video of serve. See also other serves especially those viewed from behind.
    https://vimeo.com/27528701

    (The best way to do stop-action single-frame on Vimeo is to press the play-pause button as fast as possible. Vimeo does not play on my Samsung Galaxy S2 smartphone.)

    1) When the arm is first up, straight and slightly angled to the vertical - before ISR - the racket edge is toward the ball. That's where the angle between the arm and racket is ~90°.

    2) As ISR occurs over 0.03 sec - indicated by the very rapid rotation of the elbow bones - the racket would go from edge on to face on to the ball mostly by the ISR. The angle of the arm and racket go from ~90° to the angle at impact (the so-called "β"). It is very difficult to observe pronation and distinguish it from ISR when the racket head acceleration is the highest.

    3) Some pronation may have been learned by practicing to get the right angle on the racket face. That pronation could have occurred before ISR. Most pronation occurs in the follow through. ( It is even possible that the small pronation muscles are not strong enough to pronate while the ISR is rotationally accelerating the arm. ??)
     
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  13. luvforty

    luvforty Banned

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    http://www.youtube.com/watch?v=InYd8IrFnkU

    trophy is at 00:24 - his strings are facing the right fence.... he can pancake a ball to the right if he didn't turn his body to the target.

    but he did, therefore he pancaked the ball to the opponent.
     
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  14. luvforty

    luvforty Banned

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    that looks like a spin serve, hence more 'edge on'.

    but Fed's flat serve looks like a pancake to me....

    not in the sense of a beginner pancake with E grip, but in the sense that from trophy if he doesn't turn his body at all, he can pancake a ball straight into the right fence.
     
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  15. Chas Tennis

    Chas Tennis Hall of Fame

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    All pro serves get most of their racket head speed from ISR. ISR, with a straight arm and the racket at an angle to the arm, causes the face of the racket to turn, change angle.

    "but Fed's flat serve looks like a pancake to me...." Could you find a high speed video that clearly shows what you mean.
     
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  16. arche3

    arche3 Banned

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    Just stop.... your killing me.
     
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  17. luvforty

    luvforty Banned

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    right, the face does turn, but it's always SQUARE to the path of the racket head (in the Fed's flat serve), as opposed to your vimeo spin serve where the the face is more in-line with the path, aka on-edge.

    just use the Fed video, imagine if he didn't jump, he didn't turn to the target, he only does a shadow swing with the ESR then the ISR, at what point is racket on edge?

    looks to me he would pancake that ball to the right fence (or fans in his case lol)... I don't see at any point he'd chop on-edge at the ball.
     
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  18. luvforty

    luvforty Banned

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    what? explain.
     
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  19. arche3

    arche3 Banned

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    and if he serves to the back bleachers it would be a reverse pan cake. BUT THAT IS NOT THE POINT! ahh... you serve to the other side of the net. I am getting a migrane. need to stop reading dozus' trolling.... must stop.
     
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  20. arche3

    arche3 Banned

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    stop playing tenis. no seriously. just stop. take up ping pong. its exactly like tennis. really. and you do it inside. there is a www.talkpingpong.com too.
     
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  21. luvforty

    luvforty Banned

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    ok - take a deep breath you grass hopper...

    that IS the point.... he jumped and turned therefore he pancaked to the other side of the net.

    I was trying to make a point about how you eliminate the jump and turn stuff to see what actually happened from the shoulder and up.
     
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  22. arche3

    arche3 Banned

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    just took some xanax. Im good now
     
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  23. luvforty

    luvforty Banned

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    to be serious though.... tell me, at which point is Fed swinging on edge.... take a snapshot, or just say pause at 0:xx seconds.

    I am looking at this over and over, that racket looks like a barn door opening and closing.

    what am I missing? seriously.
     
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  24. jmnk

    jmnk Professional

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    well, your description is kind of like this Seinfeld yada-yada-yada episode. Sure, he does have racket facing the right fence at 0.24 there's a lot that happens from that moment till he actually hits the ball.

    I mean 'he could have' just pancake the ball from that 0.24 position - but he doesn't. No one with proper serve does.

    his ball striking side of racket goes through;
    facing right fence, top up, at 0.24
    facing left fence, top down
    going up, edge facing the ball (at around 0.31), racket face still facing left fence,
    finally as the arm pronates the face is hitting the ball squarely
    racket face continues to turn from left facing to right facing (as a result of pronation), and the top goes down.

    the easiest way (for me) to see what is happening. Just simple throw the tennis ball with your arm and wrist fully loose. As you start throwing motion your palm (with a ball inside it) will be facing left fence, that is if you do not force anything and let your hand do its natural thing. Stop as you just released the ball. Your palm (for right handed) will be facing the right fence (almost, depending on how well/loose you can throw). The same should happen when you serve - you will naturally pronate.
     
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  25. luvforty

    luvforty Banned

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    close enough, so the strings are always SQUARE to the path right?

    so at 0.31 edge is facing the ball, but the forward swing has not started yet! that racket is still on it's way to the extreme point of the back swing at about 0.32

    it's not yada yada....minute details like this do make a huge difference.
     
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  26. luvforty

    luvforty Banned

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    so arche3 is still digesting the xanax.... he can't find a spot where the swing is edge on.
     
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  27. luvforty

    luvforty Banned

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    also, from 0.31 to 0.32, it looks like he has started the forward swing... arm is moving forward... but the racket is still going back...

    not in the sense of absolution position, but in the sense that the barn door is still opening.

    from 0.32 to impact, the barn door is closing.
     
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  28. WildVolley

    WildVolley Legend

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    I have no idea what you are seeing, but at 31 seconds into the video of fed, the racket is coming up butt first with the hitting face pointed at the fence (imaginary) to Fed's left side.

    The racket through a combination of shoulder turn, internal shoulder rotation, and pronation needs to turn toward the ball. I wouldn't exactly call this a "pancake" motion, but if that's what it looks like to you fine.

    The important thing isn't the terminology but that you go through the proper motions to get the results you'd like. This is also why it is a little silly that people overly argue about the term "pronation" as a lot of the turning in of the racket just prior to contact is due to internal shoulder rotation and not just happening at the forearm. But it is the movements that are important not their verbal description. Long live video analysis.
     
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  29. Chas Tennis

    Chas Tennis Hall of Fame

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    I interpret full 'on-edge' usage to mean one side of the frame edge is closest to the ball and the other side of the frame edge is farthest away from the ball. A line from the ball to the center of the racket face would lie in the plane of the strings if it were perfectly edge on.

    Some suggestions for selecting videos:

    1) Videos taken where the camera is at, say 45° to the lines of the court, as in the Federer video, are not best for judging angles. Views from behind, directly in front, perpendicular to the ball's trajectory or parallel to the ball's trajectory are best.

    2) Disregard all serve videos that do not show the the full face of the racket at ball impact.

    3) Use only videos that are high speed, say, 240 fps, and have small motion blur (were taken with a very fast shutter speed). Disregard videos with motion blur that could possibly affect seeing what you are after, for example, if the face of the racket is a blur.

    Always keep in mind that the serve is a 3D motion and a camera projects that 3D motion onto a 2D plane. For dimensionally accurate video analysis multiple camera "motion capture" systems are needed.

    In the Federer video the 'edge on' condition would be as the arm first becomes straight and the angle between the arm and racket shaft is at about 90°. That would be at 33 sec.
     
    Last edited: Mar 1, 2013
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  30. Cheetah

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    Kill me now
     
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  31. arche3

    arche3 Banned

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    The still frame of the video above you posted has the racket on edge as he starts the upwards swing. Duh. I dont even need to watch the video.
     
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  32. arche3

    arche3 Banned

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    Lol right? I cant believe luv40 is serious.
     
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  33. Ash_Smith

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    Frame 7...

    [​IMG]
     
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  34. jmnk

    jmnk Professional

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    I'm not sure what you mean. It is a rather complex racket motion, barely anything is 'always'.

    sure. And than the racket face starts to turn from facing left to facing right. Ideally you want the racket to be facing opposite player's baseline when you hit the ball - so the contact is square (at least on the flat serve). The point is that during entire path, from start to finish, the racket is 'facing' the opposite baseline --only-- at the moment of contact, not before, not after. What is commonly referred to as 'pancake serve' is the motion where you have racket facing the opposite baseline (or maybe more accurately - from the side view you always only see the racket edge but never the strings) pretty much through entire motion. You can serve that way, but it requires intentionally keeping the racket in that position (meaning using muscles to do that) as you serve-swing - which is the opposite of 'being loose'. So no decent server does it.

    I know. That's why why I was making a joke that in your original description went from 'his racket is facing the ball at .024' to 'he hit the ball' bypassing everythiinh that happens in between. You know, that important yada-yada
    details :)
     
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  35. luvforty

    luvforty Banned

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    does the racket go thru a point where it's edge is facing the ball? yes

    is the path of the head at that particular moment going to the ball? no.

    actually Fed goes thru 2 of these 'edge facing points'... at 0.31 that barn door is still opening.... at between 0.32 and 0.33 that barn door is closing.

    at no point that door (racket) is moving along it's edge.

    that was my point - the teaching of swinging on edge then pronate forearm to hi-5 is wrong.
     
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  36. Ash_Smith

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    Disagree. It is (when taught well) an excellent way to teach the basic shape of this particular part of the serve, it is merely one "chunk" to be taught as part of a series of "chunks" - which, when linked together create the full, fluid motion.
     
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  37. Cheetah

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    He actually said "Federer" and "pancake" in the same sentence.
     
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  38. luvforty

    luvforty Banned

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    I partially buy that... but...

    why would you not take a student, say let him use the ESR/ISR to whack something, e.g. some wild bushes at waist or chest height, and then let him take that motion over his head to hit a tennis ball?

    sounds like more straight forward than going thru the 'chunks'.... no?
     
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  39. Ash_Smith

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    ^^^might work, but it wouldn't necessarily replicate the orientation of the racquet head required, so could/would be something to do a couple of times to help them get the feel. However, I feel it would be more beneficial if you were going to do that to just to get them to thrown stuff (racquets, balls etc) instead, but you still need the "chunked" down practice to tie it all together into the act of serving (Have a look into learning theory and hierarchical learning).



    cheers
     
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  40. luvforty

    luvforty Banned

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    I am a firm believer now.... watching him playing bird itch at the moment, and every 1st serve looks like a pancake..

    from both guys for that matter.
     
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  41. Chas Tennis

    Chas Tennis Hall of Fame

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    Nice display.

    1) Notice that the apparent length of the racket in frame 7 is very short. The racket's axis is mostly pointing back at the camera. In frame 7 the arm is approaching straight but not quite yet there.

    2) Notice that the apparent length of the racket in frame 8 is about full length. Frame 8 is just before impact.

    That apparent length change results from very roughly a 90° ISR rotation. At the same time the racket is going from edge on to the ball to face on at impact.
     
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  42. sureshs

    sureshs Bionic Poster

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    So what's the conclusion? ISR results in pronation OR pronation results in ISR or both go together and happen at the same time?
     
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  43. luvforty

    luvforty Banned

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    ok.... let's talk about frame 7...

    is player's hitting hand putting pressure on bevel 1, or bevel 3 (maybe a little on bevel 2)?

    so using the barn door closing analogy, I am saying the pressure is on bevel 3.... hence I am using the word 'pancake'.....

    surely I was not referring to the beginner pancake with face ALWAYS to the baseline.
     
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  44. Ash_Smith

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    ^^^most likely bevel 2 as that's where his index knuckle sits, but it depends how you want to define "hand" i guess.
     
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  45. luvforty

    luvforty Banned

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    a few more scuff marks on the ceiling later, I agree bevel 2 is fair....

    now asking the question the other way.... if we go to 2 extremes of this topic -

    a) bevel 3 all the way; (I call it pancake, or pie in the face)
    b) bevel 1 all the way, but at the last moment pronate to square the face;

    i believe a) is a legit serve, while b) gives you nothing.
     
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  46. boramiNYC

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    040, what you are describing is simply what happens at the shoulder. the control of racquet happens at the hand and fingers. ISR/esr and all the other movements are support system or chain to achieve the the power and control at the hand. you can focus on a part of the chain while practicing but when playing matches the focus should be at the hand if any conscious control of body is involved.
     
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  47. Cheetah

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    I will be using this quote from you from time to time if you don't mind. This will replace dozu's "human racquet" as the go to chuckle inducing quote of TT.

    ... except the human racquet quote was actually correct.
     
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  48. Ash_Smith

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    ^^^I can't think of any Pro who serves with their index knuckle on bevel 3 (but again, it all depends on what reference point you use on the hand and how you number your bevels!).

    Base knuckle on 3 is legit at the rec level, but wouldn't allow the range and variety required at pro level (remember, at pro speeds, you need shed loads of spin to keep the ball in the box - you won't generate the spin with an eastern grip serve, not without creating wrist problems for yourself anyway). Some players hit with base knuckle on bevel 1 for kick serves, as it helps set the racquet face angle to be slightly more closed for the same swing path, but I still prefer to teach it with a conti-grip and modify the path.
     
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  49. Power Player

    Power Player Talk Tennis Guru

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    Dozu was a pretty solid player. I hit with him once years ago. Didnt get a chance to hit with him this year when he came down, but hopefully again.

    It indeed seems as if he has returned to the forums. ;)
     
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  50. luvforty

    luvforty Banned

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    Ash I was going to extremes... yes bevel 3 is too strong.

    let me rephrase it -

    when you swing up - should the hitting hand pressure point on the V (an edge on chop), or on the base knuckles (door closing)?
     
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