Ball Actually "Pinched" Against Ground or Not

What reality? The only reality I've seen evidence of is the high speed video that clearly shows the ball deforming downward.

Honestly, I don't mean to be a pest but I'm trying to get to the truth here, and arguments whose sum total is "end of debate" or "you remain wrong" aren't really scientific. It would be helpful for me in understanding my error if someone would rebut the points I made in my last response to winders.

Man, all that bickering with no evidence?

Here's Ernie with an iron off the tee. The close-up of impact is even closer than that of Tiger's swing that has already been posted. Go the the 0:50 mark for the close-up.



The ball is not compressed against the ground. Game over.

EDIT: If the video isn't working (because it isn't for me), this like should direct you to the YouTube page. http://tiny.cc/tWqgx

Enjoy!

sacm3bill,

The ball deforming argument of yours is meaningless. Yes, the balls deforms slightly. But the deformation that you saw with the driver does not happen nearly to the same degree on iron shots. Also, the driver is hitting the ball just below the equator so much of the deformation is towards the ground. Irons, however, hit closer to the south pole of the ball. The more loft an iron has, the closer it hits to the south pole of the ball. The closer an iron hits to the south pole of the ball, the less the deformation is towards the ground. Anyway, drop the deformation aspect from the argument because it really has nothing to do with what is going on. Just look at the vids that have been posted by me and Alex B. All of those players are doing exactly what everyone preaches we should do: hit down on the ball with good club head lag. Who knows why many people think they actually compress the ball into the grass. It's painfully clear that they don't. As I said before, maybe people thought that is what happened years ago. But with the advent of high speed video, it is painfully clear that no "squeezing" or "pinching" the ball between the club face and turf is going on. S-

Winders, everything you just posted you've already said, and I've already responded to. Let me know when you come up with something fresh, and in the meantime I'm going to go try to improve my golf game without worrying about whether the ball is being pinched or not. Cheers.

sacm3bill,

What you saying is is that you are unwilling to be wrong so you will hang on to the "ball deformation theory" regardless of its validity. All the videos show that the ball is not compressed, pinched, squeezed or anything else against the turf when properly struck by an iron. I'm really am done this time and I doubt anyone else is going to try and discuss this with you since all it will get them is nothing but a headache! Fin! S-

sacm3bill,

I have read the whole argument, and would like to chime in. You say the ball is compressed in-between the ground and the clubface correct? In order for that to happen the ball would have to be on it's way down towards the ground. And in order for THAT to happen you would have to hit the top half of the ball. And in order for THAT to happen the club face would have to have an effective loft of -1 or less. And if all of these things came together you would make a crater in the ground with the ball sitting in it. The closest that we EVER come to "pinching" the ball in-between the ground and the clubface is when you thin a shot. What do you see in the ground when you thin a shot? A small divot that has the width of a golf ball that runs for how ever many inches. This means that the ball started to bury into the ground, but since there is an effective loft of greater than 0 it still had upwards force which causes the ball flight to be somewhat above the ground. I hope you realize that you are wrong, for your sake, and the sake of iacas who has probably seen this argument and participated in this argument many times. -907

You may have read the whole argument, but you don't seem to understand that I'm not saying the ball gets knocked into the ground and ricocheted up like a pinball. I'm saying the deformation of the ball is providing the downward component that reacts against the ground, simultaneously with the ball still contacting the clubface. The downward deformity is clearly seen in the video I provided.

Unbelievable. I had let it go, too bad you couldn't. Fine then, since you're just repeating yourself I'll do the same: The videos you posted are useless in showing what the ball is doing because they are too far away, too low resolution, and too low of a frame rate. All we see at contact is a fuzzy white blur. They don't compare to the high-res/high-frame rate closeup video I provided which shows the downward component of the ball, which you have tried to explain away with your "below the equator" theory regardless of *its* validity.

I'm fine with being shown that I'm wrong, but all I'm asking for is something other than "Your ball deformation theory is crazy talk". I dunno, maybe some links to studies or analyses of what happens at impact? Maybe some high speed videos of iron shots? Anything other than conjectures about physics from people who don't have degrees in physics? And again, yes I know, I don't have any of those either. But I've provided the driver video, the web sites that talk about pinching, and the quotes from the PGA pros who talk about pinching (in the sense of it being a real phenomenon, not a training aid). I.e., I think the burden of proof is on those who would refute all that. And I really don't think I should be expected to consider statements to the effect of "The pros don't know what they're talking about" to be valid refutation.

Does it really matter dude? Does whether I'm right or you're right have any bearing on how anybody plays the game of golf? Would my existence or Iacas' existence be that much different if one side was able to convince the other to change their beliefs? Forgive me, but I thought this was an enjoyable intellectual exercise... well, at least until winders and I started going in circles.

Not sure why you needed to make up a new thread on this. I have no comment since I am very new to golf and can only put spin on the ball by accident, but skimming these arguments, I would say the majority rules.

Not sure where the other thread is but I would like to read it to see what the arguement is. I always thought that for irons, there is a downward blow to the ball evidenced by the fact that you want your divot (or bottom of the swing arc) to be in front of the ball. For that to happen, the ball has to be hit from a downward part of the arc and squeezing or pinching the ball between the club face and ground. This also creates the backspin needed for flight and spin on wedges. Anyway I would like to see the other posts of this arguement so I can better educate myself......thanks.

http://thesandtrap.com/forum/showthread.php?t=15407

There is a downward path by the club head at the time of impact, however the club face when striking the ball is still facing away from the ground. If the club face strikes the ball, the ball will jump off the club face at an angle almost directly away from the face (actually a bit greater). When it comes to compressing the ball against the ground, feel isn't real. The only way to hit the ball into the ground is to hit it with the bottom of the club, or the leading edge on the downswing. I'll bet some enterprising golfers have found other ways, but they probably didn't help their score

Think about hitting off the tee - if you compressed the ball against the tee, you would have very inconsistent tee shots and mis-hits due to the round top of the tee. Even if swinging at a steep angle, the club is still lifting the ball from the tee, not pushing the ball into it.

I would think tangent lines come into play...thus the path of the ball. Each club & swing produces a different tangent line which is dependent upon the club's loft & the way the ball's struck. I think they didn't mean it literally when they say pinch it against the ground. I think that's the feeling that you're looking for.
I would be inclined to believe that if you literally pinch the ball against the ground you'll result in a fat shot

It depends if you are talking about a teed driver or a teed iron shot. For a teed driver, you should have an upwards blow to the ball thus not squeezing the ball into the tee. If you are hitting a teed iron, the tee should be relatively flush with the ground and hit with a downward blow during the descending portion of the swing arc. Is the ball driven into the ground.....no. Is the ball pinched between the ground and club face? It simply has to based on physics. At impact, the ball is caught between a rock and a hard place so to speak......the only direction it can go is up the club face. Imagine hitting the ball without any resistance from the ground.....based on the downward blow.....it would move downward. Since the ground provides greater resistance than void at the club face, this where it goes.....to the point of least resistance......and the resistance it does encounter creates the backward spin and launch angle. Why the arguement, I don't know.....we are talking about milliseconds and millimeters of space......but the ball does get pinched between the ground and club face for a small fraction of time.

Wow... enough already....

I really can not believe this is still being argued. I thought Iacas's post would have closed it for sure.

Allow me to summarize the proven points made:

Fact: Feel is different than real.

Fact: Hitting a golf ball is not based on the club hitting the ball, and it being deflected and compressed into then off the ground. Those that say the ball goes up just because Newton says hit down to make it go up have an incomplete understanding of impact physics and the aerodynamics concerning ball flight.

Fact: The impact conditions from a shot with a driver can be different than that with irons.

Now before you go ranting further with "but, but... my pro said hit down and pinch it against the ground" think about what you are saying and what your pro is trying to accomplish. Unless you have some superhuman talent, you cannot possibly see what is happening through impact in real time. The only thing to rely on is feel, and the explanation of how to use feels to achieve results differs for everyone. I know several golfers that already take huge divots, and telling them to "hit down and pinch the ball" would not be helpful in the least.

In case you think I am just full of it, my degree is in Aeronautical Engineering, so I have a rather educated understanding of physics and the laws governing ball flight. I'll gladly draw the force diagrams at impact conditions, but that would be excessive for this conversation.

Iacas, please close this thread. Leave it as a stickied reference for the portion of the golfing population that wants to blindly accept information instead of using their noggin.

BTW, if anyone wants to know the real science behind dimples on a golf ball, and why they improve performance, we can start another thread and I'll gladly explain it. Just let me know (pm).

Are you really claiming that you can tell whether or not there's any ball deformation in those iron impact videos that have been posted? It would be nice if we could see a high frame rate, high res video of an iron shot comparable to the driver video.

Sigh. Once again: I *never* said the ball, or even the center of gravity of the ball, ever moves downwards. Just that there is a downward deformation of the ball that is providing a force vector against the ground. Whenever someone has refuted that, their argumenent has always been "Oh, just ignore that", or "It's not as much with an iron as with a driver like in the video you posted", or "The impact conditions from a shot with a driver *can* be different than that with irons", with no data or sources or video to back it up.

Yeah, with YOU being the establishment in this case because it's your forum, but other than your say-so what sources can you provide or link to that support your position? Being the establishment doesn't automatically mean you're right, or necessarily the smartest guy in the room. Same goes for the majority argument someone else used - once upon a time the majority believed the sun revolved around the earth.

If you believe those videos are good enough to see any possible deformation, then it's no wonder we can't agree because we live in two different realities.

The degree of deformation may change with different clubs, but the physics of impact don't.

Fair enough. Just curious, which ones have you asked? If you haven't, then it's just conjecture on your part.

Sorry, I didn't realize I was off topic. I would think that whether a ball flies differently off a tee vs the ground is relevant to whether one should tee it up or not.

Again, my apologies. If you had requested I had started a new thread myself I certainly would have done so.

Nice.

If the counterargument to mine had been, "Yeah, I see the ball deformation with the driver, and I know we don't have the same quality video for iron shots but still I don't believe the ball deforms as much there, and even if it did I don't think it deforms enough to have a pinching effect...", then I would've said, "Yeah, you could be right, guess there's just not enough evidence to know for sure", and I would've been gone a long time ago. It's the know-it-all attitude, bullying, and insults that have kept me around just so I can defend myself. - Bill

Glad you brought up the impact diagram.....because I was thinking of doing the same thing.....although I am a Civil Engineer......I still have a good understanding and physics and dynamics. Since we are putting out facts.....

FACT: It is a common principle for a proper a swing, a divot should be taken IN FRONT of the ball....correct? If that is the case, the force initiated on the ball would have to come from a descending blow in order for the swing arc to bottom out in front of the ball. FACT: A descending blow would then create downward force against the ground thus creating the "pinch". FACT: As a result of the "pinch", backspin is created as the ball travels the face of the club. The backspin is what in fact creates the trajectory of the ball and the amount of backspin (trajectory) is based on the loft of the club. FACT: Distance is created by increased force of the club faced from the increased length of the swing arc since longer irons have longer shafts. Both sides are right.....and both are wrong. I look at it as being similar to striking a pool cue....a downward blow creates the backspin (english) to create backward spin. Bottom line, I will continue to "pinch" the ball to the ground whether it is real or imaginary if that is what I need to do in order to strike the ball cleanly.

This site has a good explanation....

www.lifeintherough.com/2007/09/26/misunderstood-advice-hitting-down-on-the-ball/