Wednesday, December 7, 2011
Force And Golf - Part II
In part II, we will discuss force and putting.
One of the questions I received from readers on my putting stroke mechanics series was 'why do heavier putters work better on faster greens and lighter putters work better on slower greens?'
The main point behind that concept is this: we want to make it so the golfer does not have to adjust their stroke too much going from one green speed to another.
This is a concept that companies like Edel Golf, who have interchangeable weight system in their Vari-Weight putter line, utilize.
So, let's go over some brief putting stroke concepts:
Tempo - The rate at which the putterhead swings in the stroke. Tempo can be fast, slow or somewhere in-between.
Rhythm - Keeping the tempo of the putter the same going back as it does thru. Not being able to do that is 'poor rhythm.'
Stroke Length - The length that the golfer swings the putterhead back. Typically, the longer the putt the longer the stroke length.
Now remember, we really want to keep the rhythm in tact. It doesn't quite matter what type of stroke you utilize or grip you use or if it's a fast tempo or a slow tempo, we want to have 'good' rhythm in our putting stroke.
Thus, what tends to alter as the green speed changes is the tempo and the stroke length. And that's where chaning putter weight can play a big role.
But, we have to go back to 'force.'
Force = Mass x Acceleration
Now, what do we know about green speeds and putting?
Faster Greens = less force required to get the ball to the cup.
Slower Greens = more force required to get the ball to the cup.
So, when we are on a faster putting surface, we increase the weight because that slows down our acceleration, which creates less force for a putt that requires less force.
Conversely, on slow greens we make the putter lighter because that increases our acceleration. This creates more force for a putt that requires more force.
Let's say you have a 30 foot putt. Your first time putting it's an 8 on the stimpmeter. The second time you putt, it's the same putt except the speed has been alterd to a 10 on the stimpmeter.
If you appropriately change the weights, and make the putter heavier with the faster stimp, you will have to make less of an adjustment to your putting stroke length and tempo. Your tempo will more naturally slow down because the putter is heavier, so will your acceleration.
So let's say you take that 30 foot putt on an 8 stimp and your backswing is 15 inches long. With the same putt on a 10 stimp, with the weight changed, that backswing may be 13 inches long.
But, if you didn't change the weights, you may go from a backstroke of 15 inches long on the 8 stimp to a backstroke of 7 inches long on the 10 stimp.
Thus, the change in weight allows the golfer to do less alteration of their putting stroke and that tends to make it easier for them.
FORCE AND PUTTING STROKE TECHNIQUE
We'll go back to part I where I discussed more of a 'full sweep' release versus 'snap' release in the golf swing.
Here's John Senden with the 'snap' release.
Here's Shane Bertsch with a 'full sweep' release.
There's a similar type of concept in putting. Somebody with a wristy stroke, like Arnold Palmer, is more like John Senden (snap). Somebody with a swinging/pendulum-esque stroke, like Ben Crenshaw, is more like Bertsch (full sweep).
The acceleration is different as well. Arnie's wristy stroke is more likely to accelerate more than Crenshaw's swinging, pendulum-esque stroke.
That's why most good wristy putters employ shorter and faster tempo strokes. While one could use a wristy stroke that is long and slow in tempo, it's a bit difficult to do since the wrists really want create more acceleration. Conversely, the swinging stroke usually creates less acceleration and the golfer has to find a way to get the ball to the cup, so they create a larger stroke.
In the end, the idea is that one can putt well with a wristy or swinging stroke, but they should probably try to find the compatible stroke length and tempo with that stroke action, otherwise they will fight consistently applying the right amount of force on the ball.