Why the ball does what it does

Dave Gremmels

It is amazing to me how many golfers don't really understand why the ball slices, pushes, pulls or hooks.  If a slice occurs, a typical golfer will say " I cut across that one" without understanding the dynamics of what is really happening.  We get caught up in the mechanics of the swing to correct our faults.  We know that in order to correct a slice we need to swing more from the inside out.  So if golf instruction is there to correct our hooking and slicing problem then why is it important to understand what is actually happening in terms of spin on the ball? 

Anthony Kim made a comment that he really doesn't know mechanically in his swing what he does to make the ball fade or draw, he just does it.  What this comment means is that he has to conceptually know what happens in terms of spin to the ball to get it to do what he wants it to do.  He has a clear understanding of what makes the ball hook, fade, slice or draw.  He can visualize what he wants to do in terms of spin and his swing adjusts for the desired result.  He is not focusing on mechanics only in terms of concepts.

This brings to light the fact that the golf swing is happening so fast that it is impossible to physically make changes on a conscious level during a golf swing.  Everything must be preprogrammed to be effective.  A.J. Bonner has a video out (The Truth About Golf) that is fantastic in developing an understanding of what the objective is in the golf swing. 

I believe that it is absolutely critical to understand what is happening to the ball in terms of swing path, clubface angle and the resulting spin on the ball before any correcting instruction can be effective.  Without a clear understanding and a visualization of what the objective is, the swing cannot be effectively preprogrammed to accept the physical swing instruction being taught.  In other words, if you can visualize what you are trying to do to the ball, the instruction you are trying to apply will be putting your body in a position to be able to achieve your objective.

Having said all this it is time to take the confusing journey of what is actually happening during the golf swing that make the ball do what it does.

There are two forces at work.  One is swing path, the other is the angle of the face at impact.  The many combinations of these two forces produce the ball flight of your shot.  It is easy to understand a straight shot.

The face of the club is square to both the target line and the swing path of the club.  The result is straight shot, no side spin.

What if the clubface is square to the target line but our swing path comes from the top of the target line ( outside to in) and goes on a path that is 5 degrees to the target line?  What will happen?




The ball will receive a side spin because the face of the club is square to the target line but is going across the ball at 5 degrees.  You will notice that the club is not square to the swing path, just the target line, therefore the ball will slide from the heel of the club towards the toe.  This movement on the face of the club produces spin.  This will result in a shot that will start left of the target and slice back towards the target.

The reverse would be a hook.

The ball will start out to the right of the target and hook back.  The swing path is from below the target line to outside the target line or inside out.  The ball will move along the clubface from the toe towards the heel, putting a draw spin on the ball.

Now lets look at a constant swing path that is along the target line and with a change in face angle.

This will result in spin that will start the ball at the target for a few feet but will quickly slice to right of the target.  The face of the club is 5 degrees right of the target line (open).  The spin on the ball is a result from the ball rolling from the heel to the toe as it is struck.

The opposite is true for a clubface that is left of the target line (closed clubface).

The result will be a hook where the ball quickly goes to the left and goes further left from the spin as the ball moves on the clubface from the toe towards the heel.

So far things are pretty simple to understand, however the fun starts when we look at the combination of different swing paths combined with different face angles.  Swing path and face angles will work in combination or counteract each other to produce varying results.  We will start simple.

Push and Pulls:

If the swing path and the face angle works against each other to the point that they negate each other the result will be no spin on the ball but flight that will not go at the target.

Can you guess what this will do?

If you said pull, you are correct.  The ball will fly left of the target with no spin, so it will be straight, but left.  The swing path being 5 degrees outside to in is counteracted by the clubface being 5 degrees closed.  No spin will result.  You will notice that the clubface is exactly square (perpendicular) to the swing path, which is the cause of no spin being applied to the ball..

The opposite produces a push.  This is a ball that goes straight but to the right of your intended target.

A push or pull is a case where the face angle is counteracted by the swing path.  One is working against the other for a net effect of zero spin.  What about the case where they combine and work together?

The face of the club is 5 degrees open and the swing path is 5 degrees outside to in.  This combination produces a 10 degree slice.  The ball will turn to the right quickly and have the compounded spin that will produce a large slice.  The club is 5 degrees open to the target line, but because the swing path is 5 degrees open to the target line the combination produces 10 degrees of slice spin.

The opposite occurs when the swing path is from the inside to out and the face is closed.

Can anybody say duck hook?

This example is one that has a lot of confusion associated with it.  A golfer who normally slices hits this shot and thinks they put a hook swing on it, when in fact it was a slice swing (outside to in) with a clubface that was closed more than the target line swing path.

The swing path is 4 degrees outside to in (slice path), the club face is closed 7 degrees (hook club face).

The ball will start left then go further left because it has 3 degrees of hook spin on the ball.  A golfer could easily be fooled into thinking that they did something right that got rid of their slice, and now they only need to aim farther to the right.  In fact aiming more to the right will make the swing path even more outside to in as they try to swing the club back to the target.

The real world in golf produces all types of different combinations.  I would however like to illustrate a combination that would be beneficial to the average player.

Here we have a 4 degree inside out swing path that will produce a 4 degree draw ( or mild hook).  However the clubface is 2 degrees open, this will produce a fade (or mild slice) spin.  The net effect is a 2 degree draw.  This is a shot that will start out to the right of the target and gently curve back in.  This demonstrates that you can have an open clubface and still hit a draw. 

You can see that all different combinations are possible.  You will have to digest them for yourself.  Having a clear understanding of these principles will go a long way to improving your golf swing.  Perhaps now you can see how Anthony Kim can look down at the ball in relation to the clubface and visualize the clubface coming slightly outside to in while keeping the clubface square to the target line to produce a fade.