Open Stance

[CraigC]

Huh??

I am going to disagree with John, which I so rarely do, although I think we should clarify things here.

F=m x a.

So, does this mean weight transfer has zero effect on the shot, or that it is irrelevant. I would argue that point. There is a significant difference in the ball when I am leaning in versus leaning back. That is not to say one cannot hit with a similar racquet speed, but the weight of the ball is heavier with a greater mass behind it.

Now, I know that spin is the relevant factor in heaviness, but I would consider the weight transfer in hitting a heavy ball to be vertical, rather than horizontal. John, would you please explain how weight transfer is nebulous. If this is so, why do we push so hard off the ground to create force. If so, why do so many players move through their shots? If so, why do volleyers hit while stepping in, rather than playing more open stance shots? ( Is it merely to create better angles)

This thread just opened up a whole can of...

[lukman41985]

John, would you please explain how weight transfer is nebulous. If this is so, why do we push so hard off the ground to create force. If so, why do so many players move through their shots? If so, why do volleyers hit while stepping in, rather than playing more open stance shots? ( Is it merely to create better angles)

Mr. Cignarelli,
Please allow me to respond. Weight transfer is nebulous in the sense that the alignment of our body to the ball, back posture and the alignment of the feet to the target line are not used to transfer weight by stepping in, but instead, have an effect on the path the racquet will travel upon. Pushing off the ground, moving through the shot, and stepping in to hit volleys are movements that facilitate a certain path the racquet will travel upon. The reason why coaches cringe when they see players jump on groundstrokes is because mis-hits and loss of power result. Why? Because as you jump, your body pulls up which causes the racquet to be pulled up as well. The result is usually too much movement of the racquet in the vertical direction and not enough in the horizontal direction. However, if one stays grounded, with a straight back, and alignment of the feet towards the intended target, the chances of hitting an accurate shot are increased significantly. Playing shots open stance can be risky in the sense that unless the student has a feel for the racquet traveling through the shot, the student will come off the ball and off the line of the shot too soon. Also, open stance, as Kerry Mitchell has mentioned, is misunderstood. What matters is your alignment to where you want to hit the ball. That force equation is correct but what mass are we talking about? What acceleration are we talking about? I believe that in hitting a tennis ball (which has its own mass and acceleration) the most important mass is the mass of the racquet and the most important acceleration is the acceleration of the racquet. To reiterate, body positioning and alignment are important in so far as facilitating the path of the racquet--not in transferring weight.

[johnyandell]

I think we can easily get hung up on the terminology here. Obviously the weight of the body is getting moved around. And pushing up from the court sets that in motion. The idea of "weight" being applied to the ball is the confusing part. What happens with the body will affect the speed and direction of the racket, but the mass in the equation is still the racket. Transfering the weight into the shot is another way of saying that I position my body in such a way that I can move my racket along a certain path at a certain speed.

I think it all boils down, once again, to positions and movements--what the physics of it are and what we call it are interesting--but can also be confuing.

By the way, no one (Lukman) would suggest using a closed stance for the forehand. But if I "step into the shot" with a netural stance that may facilitate coiling and uncoiling of the front leg, which may add to the speed of the racket.

I think the hardest part is once you have determined what the model looks like--how to you recreate that for a player. This forces you to address the issue of cause and effect. As with the wrap, do the extra steps and movements through the shots occur as a result of what precedes them or do they have to be menchanically generated? To me this is where the interesting discussion lies.

[lukman41985]

What happens with the body will affect the speed and direction of the racket, but the mass in the equation is still the racket. Transfering the weight into the shot is another way of saying that I position my body in such a way that I can move my racket along a certain path at a certain speed.

This is exactly what I've said. I see no disagreement between us...

[johnyandell]

Well not sure about that as I am definitely not advocating that players stay on the ground. Some balls they will, others not. And when they come up into the air it doesn't necessarily mean they have transfered less energy into the ball--often it's probably more.

[tennismaverick]

I thought for sure you would have agreed with me that the weight is being transferred form the players back side to front side regardless if the player comes off the ground or steps into the ball. I did review many videos of players before I asked that question and did so again. On many of them the player is definitely transferring their weight from their back foot to their front foot in an open stance. Unfortunately I don’t have quick time pro so I can’t post them here. The same is true if they come off the ground. If you go to this link on your website and scroll down to the Hewitt video, you will see that he moves significantly forward.

http://www.tennisplayer.net/members/teaching_systems/welby_vanhorn/true_master_balance/true_master_balance_pg2.html

Welby Van Horn is also stressing weight transfer in this article as increasing your power.

The clip you have of Roger seems more of a defensive shot. That is he is moving backwards to let the ball drop into his hitting zone or give him more time to prepare. But if you look at clips of Roger or most players, especially the women, when they are hitting an attacking shot they almost always transfer their weight onto their front foot or forward if the whole body leaves the ground. This gives them much more power. Maybe we disagree on why this gives them more power? I agree with your assessment that transferring the weight aids in the body uncoiling since this is the start of the kinetic chain. This is really obvious in baseball hitting. Try to hit a baseball without stepping into it. The ball will barely get out of the infield. The significant extra power comes from the weight transfer and the uncoiling of the hips then shoulder etc into the ball. The same is true in tennis. Try hitting the ball by keeping your lower body completely stationary and just swinging your arm. You won’t have nearly the amount of power. Of course no pro just stands still and swings his arm. How much of this extra power is from the increase in uncoiling speed and how much from weight transfer? I guess we need to test that by getting someone who weighs 80 lbs and have her step into the ball but not swing her arm or move her body in any other way. Then have someone who weighs 200 lbs do the same thing and see how much further the ball goes. My guess is the ball would go further with the 200 lbs man because of the extra weight. F=MA is true because it is not only the racquet weight but the body weight. The body weight won’t transfer over completely unless someone had a super tight grip on their racquet. There is a loss in energy transfer because it is not humanly possible to have a perfectly tight grip and in tennis you don’t want that anyways. An analogy would be if you got into a head-on car crash with a Toyota Corolla versus a fully loaded semi-truck traveling at the same speed. Obviously the semi truck will cause much more damage because of the extra weight. But how much loss is their in the tennis grip per Newton’s formula F=MA? I don’t know and I don’t even know how to figure that out. But I would like someone to do the above experiment. If I can find some people to do it I will. I think John, at your tennis center, could easily do this experiment with many people to get consistent results that can be replicated. A person’s weight might not have anything to do with power at all. It would be interesting to see the results of this experiment.

[johnyandell]

The difference is semantic. Sure the weight is being shifted from one foot to the other. Thats' true in the Federer example I posted. I looked thru a dozen or so women's open stances and found one of Justine where the front foot landed forward. The others, no. It's backwards or sideways. If you want, just copy the URLs from the ones you are talking about and past them in the browser do that and people can click and look.

But again, the f=ma thing doesn't exactly apply! The mass is the racket. How the weight shifts around can affect the path or velocity of the racket. For example in a neutral stance, the step into the shot probably adds an increment of racket head speed. But it's not the "weight" perse.

The weight thing? I've been on the court with 100lb girls who could blast me off the court. AND 250 weight lifters who couldn't break an egg.

The term itself to me is less important than the shape of the stroke and the position and movement of the body parts.

[tennismaverick]

I agree that the shape of the stroke and the movement of body parts are the most important but I think transferring the weight forward helps the movement even if it doesn’t add any significant power. I also agree the weight of the racquet is most significant. I am just not sure if the body weight makes any difference. It might not. Maybe it’s just the momentum of the body going forward versus backwards that makes a big difference? Obviously if I am moving backwards and hitting a slow paced ball, I can’t hit it as hard as if I were stationary or moving forward.

Here is a couple with Maria and her weight ends up on her front foot because her back foot comes off the ground.

http://www.tennisplayer.net/members/strokearchive/pro_woman/maria_sharapova/ms_forehand/ms_fh_center/ms_fh_center.html?MSFHCenterFront2.mov

http://www.tennisplayer.net/members/strokearchive/pro_woman/maria_sharapova/ms_forehand/ms_fh_center/ms_fh_center.html?MSFHCenterRear1.mov

http://www.tennisplayer.net/members/strokearchive/pro_woman/maria_sharapova/ms_forehand/ms_fh_center/ms_fh_center.html?MSFHCenterCourtLevelRear.mov

http://www.tennisplayer.net/members/strokearchive/pro_woman/maria_sharapova/ms_forehand/ms_fh_center/ms_fh_center.html?MSFHCenterOpenStanceRear2.mov

Here is one with Serena:
At the end of the stroke her back foot is off the court proving all her weight is on her front foot.

http://www.tennisplayer.net/members/strokearchive/pro_woman/serenawilliams/sw_forehand/sw_fh_center/sw_fh_center.html?SWFHCenterFront1.mov

http://www.tennisplayer.net/members/strokearchive/pro_woman/serenawilliams/sw_forehand/sw_fh_center/sw_fh_center.html?SWFHCenterOpenStanceFront2.mov

Here are a couple of shots of Pete. It sure looks like his weight is being transferred into the ball even though his front foot ends up a little behind from where it started.

http://www.tennisplayer.net/members/strokearchive/pro_men/petesampras/ps_forehand/ps_fh_center/ps_fh_center.html?PSFHCenterFront1.mov

Look at his back leg. It ends up moving forward. How could this happen unless he is pushing off it into the ball and rotating in the air?

http://www.tennisplayer.net/members/strokearchive/pro_men/petesampras/ps_forehand/ps_fh_center/ps_fh_center.html?PSFHCenterDowntheLineRear1.mov

A couple of Roger:

http://www.tennisplayer.net/members/strokearchive/pro_men/rogerfederer/rogerfederer_forehand/rogerfederer_fh_center/rogerfederer_fh_center.html?FedererFHCenterNeutralStanceFront.mov

http://www.tennisplayer.net/members/strokearchive/pro_men/rogerfederer/rogerfederer_forehand/rogerfederer_fh_center/rogerfederer_fh_center.html?FedererFHCenterCourtLevelFront3.mov

In this one his front leg ends up moving backwards but unless he is pushing off his back leg into the ball which causes him to rotate around and subsequently his front leg ends up behind, how else would he get into that position?

http://www.tennisplayer.net/members/strokearchive/pro_men/rogerfederer/rogerfederer_forehand/rogerfederer_fh_center/rogerfederer_fh_center.html?FedererFHCenterCourtLevelFront2.mov

Hewitt:

http://www.tennisplayer.net/members/strokearchive/pro_men/lleyton_hewitt/lh_forehand/lh_fh_center/lh_fh_center.html?LHFHCenterFront.mov

Agassi:
Notice how his momentum carries him into the court

http://www.tennisplayer.net/members/strokearchive/pro_men/andreagassi/aa_forehand/aa_fh_center/aa_fh_center.html?AAFHCenterFront1.mov

[johnyandell]

I think the stance will be a function primarily of ball height in the pro game (and should be at all levels!) So a lot of those examples are actually netural stance where the player is stepping in. Again, My personal opinion is that the weight is not "transferred into the shot." Again, the racket hits the ball. Yes there is a transfer of weight forward to the side, back, from one foot to the other or not, etc. The players do very many different things depending on the circumstance of position, type of ball, type of shot, etc.

I think when you start to try to "move your weight" as an independent factor rather than as a function or consequence of the underlying fundaemtnals the stroke pattern, you can get some artificial movements that can appear quite awkward even in highly trained juniors.

Just my opinion. I feel that the proof is always in the player's stroke. So how a coach works or communicates to get a player to develop certain patterns/abilities is really a form of psychological art... It's not necessary that the exact ideas or phrases even correspond to reality or to the reality they produce.

[davehagler]

stance determinants

I think that ball height and TIME determine stance(s) as much as anything. People - we are dealing with an open skill sport here, and as a result a player rarely gets to hit the "same" shot over and over. Variability in position on the court, height, spin, velocity and trajectory of the incoming shot, desired result, etc. A player also has to be concerned with the next ball - and most of the time it is a very good idea to assume that there will BE a next ball. The "problem" with closed stance forehands is that body rotation is impeded and the kinetic chain is broken.

A lot of what seems to be stressing people seems to be more of a result than a cause. Some of this has been said in other posts. "Leaning" seems to be shot specific - it might make sense to have a forward "leaning" body alignment if you are driving a high ball that is rising and you want to take it before it gets out of your comfort/power zone. "Jumping" is the result of loading (and then unloading). If you "jump" you will probably lose power. If you come off of the ground as the result of leg push you might well be o.k.

If you want to talk about baseball hitting there are two main schools of thought in that area as well - "weight shift" and "rotational." I recommend the following books: The Mike Schmidt Study, ISBN 0-9634609-2-7, The Science of Hitting (Ted Williams) ISBN 0-671-44913-3, and The Art of Hitting .300 (Charley Lau), ISBN 0-525-48219-9

By the way - even serving and throwing are NOT the same it seems that people who can throw well almost always serve well while the converse is not necessarily true. Kind of off topic but ---

[tennismaverick]

John you said, "I think the stance will be a function primarily of ball height in the pro game (and should be at all levels!)"

So does this mean the higher the contact point the more open the stance? So if you hit the ball between your waist and your shoulders you should use an open stance and if you hit it at waist level or below you should use a neutral stance?
I see the pros, especially Federer, Agassi and Sampras, switching between an open stance and a neutral stance all the time and I'm not sure why. Thanks.

[johnyandell]

That's what I see. If the ball is low--which is relatively rare--you see them step in and hit with a netural stance--or in the case of Agassi or Federer when they want to take the ball on the rise.

The higher balls above waist level will be either semi-open or fully open. But again if you get aligned behind the ball with the back foot and if you are correctly turned, you will feel which stance works for the given ball without having to think "open"? "semi-open"?? etc.

I'd bet a hundred bucks that if you are having problems with this, the roots are in the preparation and movement.

[tennismaverick]

Thanks. Outside of maybe 5.0 or higher level it doesn't seem that most players hit the ball hard enough or with enough spin that you can't position yourself to hit the ball in basically the same contact point most of the time. Certainly at the 4.0 level or below, people have plenty of time to position themselves to hit the ball at waist level most of the time or whatever their correct contact point is. So switching between the two stances probably only applies to higher levels of play and certainly at the professional level and only occasionally at the lower levels. At lower levels it seems deciding the correct contact point for you and trying to hit the ball their every time and using the correct stance for your grip and the ball height is more important. So if you use an eastern grip than hitting the ball at waist level most of the time in a neutral stance would be more effective for you. If you use a semi-western or western grip than hitting the ball above your waist and with an open stance most of the time would more effective. This probably seems like an obtuse post but many of the articles on this website are analyzing the pro game. How an average player adopts that analysis to his game can be confusing.

[johnyandell]

Yeah except for the loopers and moon balls. I think a lot of lower level players should/will hit semi-open.

It's a good point about the pro analysis. That's the "proof" or the way people think things are proved. But I think eventually we can balance that with more direct applications to all levels.

[tennismaverick]

BTW, I found a book called The Physics and Technology of Tennis written by three physicists who have dedicated much of their professional life studying the physics of tennis. Crawford Lindsey, Howard Brody and Rod Cross do an excellent job describing almost every aspect of the physics of tennis in this large, comprehensive and detailed book. I have only read a small portion of this book but from what I can tell (its pretty technical) the M in Newton’s famous formula F=MA is only the tennis racquet as John Yandell said. So a person’s body weight makes no difference. Another physicist, who did a study on baseball hitting, told me that you could throw the bat at the ball and it would have the same effect as swinging it. So this could be applied to tennis as well.