Divots on practice swings.

[fisher]

I played at a very exclusive private course today. One of those places where you don't see a divot anyplace. One of the guys in the foursome would take a full practice swing with divot before each shot. Am I the only one that frowns on this? It was making me sick to watch and then I was the one going back and sanding his divots and practice swing divots. I'm not talking brushing the grass here, Im talking 6 inch long practice divots. Some were even chunked practice swings.

 

[FATC1TY]

I feel the same way.. I usually try and sand my divots if I can, or atleast replace it the best I can sometimes.

But taking a divot on a practice swing is silly. You get all that turf on your club, in your grooves, and then you have to clean the damned thing for the shot.

I would have said something after he did it more than a handful of times and had no idea what he was doing.

 

[Bignose]

There was some nice analysis I read a while back that showed that the divot is actually the result of a swing that without the ball would just brush the tops of the grass. The difference is that when there is a ball there, the force of the ball going up also forces the clubhead down a little bit. Basically, it is just Newton's third law of motion in action -- equal and opposite forces. The upward force on the ball and the downward force on the clubhead must end up equal and opposite.

This also explains a lot of why wedges and short irons take greater divots than long irons and woods. Wedges and short irons put a lot more up on the ball and hence put more down on the clubhead.

I had a hard time believing it at first, but the math I saw I thought was done well and came up with a good answer. The analysis predicted about 1/4" or so for an 8 iron.

Since I read that, I've actually noticed that several pros take practice swings that just brush the top of the grass, but then take significant divots on their real swing. Makes me think that if you are taking a large divot on a practice swing, that not only are you showing disrespect (especially if you don't sand or replace), but that you are probably practicing the wrong thing, too.

 

[eclark53520]

There was some nice analysis I read a while back that showed that the divot is actually the result of a swing that without the ball would just brush the tops of the grass. The difference is that when there is a ball there, the force of the ball going up also forces the clubhead down a little bit. Basically, it is just Newton's third law of motion in action -- equal and opposite forces. The upward force on the ball and the downward force on the clubhead must end up equal and opposite.

This also explains a lot of why wedges and short irons take greater divots than long irons and woods. Wedges and short irons put a lot more up on the ball and hence put more down on the clubhead.

I had a hard time believing it at first, but the math I saw I thought was done well and came up with a good answer. The analysis predicted about 1/4" or so for an 8 iron.

Since I read that, I've actually noticed that several pros take practice swings that just brush the top of the grass, but then take significant divots on their real swing. Makes me think that if you are taking a large divot on a practice swing, that not only are you showing disrespect (especially if you don't sand or replace), but that you are probably practicing the wrong thing, too.

Anyway you could possibly find that? Not calling you out, or anything, but i am having a hard time believing the ball is the only thing causing divots...but would definitely like to read the study.

 

[NBGolfer]

I feel the same way. Taking divots on practice swings is not something I do, or see any benefit to. I would think most people do this by accident.

As far as why you take greater divots with shorter irons (Newton's law post) I would think that is more do to ball postion between your feet, and trying to pinch the ball against the grass with your shorter irons.

 

[FATC1TY]

Anyway you could possibly find that? Not calling you out, or anything, but i am having a hard time believing the ball is the only thing causing divots...but would definitely like to read the study.

I think pro's brush the grass on their practice swing because they know it's stupid as hell to hit the ground on a practice swing. When they hit the club is going to hit the ground because it's the bottom of a swing arc in front of the ball....

I didn't think there had to be that much science to it..

 

[indacup]

Anyway you could possibly find that? Not calling you out, or anything, but i am having a hard time believing the ball is the only thing causing divots...but would definitely like to read the study.

B.N. is absolutely correct....I believe I can pull up material from Tom Wishon to support it.

Matter of fact, I bet I can pull up video clips showing it happening....

Think about it....you are swinging down with your irons......brushing the top of the grass with your practice swing...and then, placing an object over 1.5" in front of the object hitting the ground.

It is the "pinching" effect of the ball between turf and clubface that dictates trajectory and spin.

Taking this topic a step further, I (internally) chuckle at a few partners who on the tee box brush the top of the grass with their driver....then tee it up 2".

Then they complain about high ball flight and excessive spin.

 

[slickpitt]

I take a full practice swing... but generally speaking I just barely brush the grass. Every once in a blue moon I'll chunk my practice swing and think "hot shit glad that wasn't my shot"! lol

But yes I frown on intentionally taking a divot with practice swings.

 

[BrandonM7]

I take a full practice swing... but generally speaking I just barely brush the grass. Every once in a blue moon I'll chunk my practice swing and think "hot shit glad that wasn't my shot"! lol

But yes I frown on intentionally taking a divot with practice swings.

Same here, including the wording of the thought.

 

[floggerrushmd]

So while reading this I thought of something. When taking a practice swing on the fairway or tee, taking a divot is idiotic, and disrespectful to the course. However, when playing out of the rough, off pine needles, or some other lie where the surrounding turf could determine how the shot is played I am all for taking divots on practice swings. Get the full feel of how that shot will be played. Just my $0.02

 

[SilverUberXeno]

I hadn't considered it before but I believe Bignose explanation makes perfect sense. Think about this.

We've all seen swingvision (konika minolta bizhub decagon godzilla) with iron shots.

When the clubhead strikes the ball, there is significant deflection. The head bends back away from the target when it contacts the ball; simply physics. The grip and higher portion of the shaft are still moving forward, but the clubhead is slowed down significantly when it strikes the ball.

This does not happen without a ball. As a result, the clubhead travels through the hitting area lower than it would otherwise.

The end of this video shows it reasonably well.

YouTube - SwingVision - Tiger Woods Iron Part II

You can see in this one during the full swing just how much the shaft deflects. The closeup at the end confirms it further. That clubhead was NOT going down that far prior to contact with the ball.

YouTube - Sean O'Hair Iron SwingVision

 

[Wi-Golfer]

Taking divots on practice swings is asinine, I avoid it by not taking practice swings.

 

[fisher]

So while reading this I thought of something. When taking a practice swing on the fairway or tee, taking a divot is idiotic, and disrespectful to the course. However, when playing out of the rough, off pine needles, or some other lie where the surrounding turf could determine how the shot is played I am all for taking divots on practice swings. Get the full feel of how that shot will be played. Just my $0.02

I'm talking about the tee boxes and fairways here.

 

[shane0mac1234]

I dont know about all the physics but I mean do you really need the full swing? The guys on tour dont really take full swings before their tee shot they make sure they are loose and aligned properly, they do basically the same for shots on the fairway etc.

One big reason, if you are taking a full practice swing or more for every shot you take, you are going to be EXHAUSTED. I mean you would be taking soooo many more full strokes then needed, I go through the basic major points in a slow smooth fashion, but really no need to go all out, it is just overkill

 

[295yards]

I hadn't considered it before but I believe Bignose explanation makes perfect sense. Think about this.

We've all seen swingvision (konika minolta bizhub decagon godzilla) with iron shots.

When the clubhead strikes the ball, there is significant deflection. The head bends back away from the target when it contacts the ball; simply physics. The grip and higher portion of the shaft are still moving forward, but the clubhead is slowed down significantly when it strikes the ball.

This does not happen without a ball. As a result, the clubhead travels through the hitting area lower than it would otherwise.

The end of this video shows it reasonably well.


YouTube - SwingVision - Tiger Woods Iron Part II

You can see in this one during the full swing just how much the shaft deflects. The closeup at the end confirms it further. That clubhead was NOT going down that far prior to contact with the ball.

YouTube - Sean O'Hair Iron SwingVision

The theory was as the ball is being pulled up the face from the contact with the grooves the clubhead is also being pulled down which totally makes sense.

As far as shaft bend or flex, it cannot extend outside the swing arc. If that shaft flexes it would actually shorten the swing arc.

If you watch both those video agains the shaft only bends after the clubhead comes into contact was the ground.