Getting the Ball to the Hole: The Faster You Putt, the Smaller the Hole (Lesson 3, Part 5)

Jack makes a putt on the final 9 at August, 1986.

The harder I try, the behinder I get.

                      Anonymous

Work hard to reach your goals. And if you can’t reach them, use a ladder.

                     Yogi Berra (2007 Commencement Address)

This is the next part in this series: The question is, to die the ball at the hole or to putt it 17 inches past?

Let’s start with the simple.  A golf ball that is not moving.  When a ball, as in Figure 1, does not have its center of mass over the hole , the ball will not drop.  It’s as simple as that.  For a ball to fall, its center of mass must lie over the edge of the hole.

Figure 1

Figure 1

On the other hand, if you put a golf ball with its center of mass over the edge of the hole, it will fall, again, no matter what.  Figures 2 and 3.  No question.  It will happen — assuming the system is stationery.  Just place the ball with its center of mass even barely over the edge of the cup, and it will fall in.  (Figure 3 gives a side view to emphasize that the ball will fall.)

Figure 2

Figure 2

Figure 3

Figure 3

Let’s complicate it a bit.  Now let’s have the ball move.  We know it’s not quite as simple as just having the center of the ball over some part of the hole.  We’ve seen lip outs. Why does it lip out? See [1] Watch Phil Mickelson lip out here, missing a 59 on the last hole of the Phoenix Open.   We’ve seen a ball headed right for the center of the cup and hop over it.  [2]  What are these things about?  Let’s hold off on that just a bit.

The figures make a very simple point.  If you can stop the ball just at the hole and the ball hangs over the cup, it will drop.  Die the ball at the hole, on target, or using any part of the cup, and it will fall.

So why putt it 17 inches past?  Or as Nick Faldo recently claimed on a CBS telecast of the Farmers’, after watching Phil Mickelson miss a putt long, “we now know scientificall that putting it 12 inches past allows us to use the full circumference of the cup.”

What is the truth here

The truth is that a ball moving with any velocity and that has its center of mass over the cup at some point will not necessarily fall.  Why not?  Because if it is moving fast enough, gravity will not pull the ball down into the hole (accelerate the ball fast enough) so that ball will move more down than forward; in other words, it will not fall.

Imagine the ball moving as in Figure 4, where it just momentarily would have its center of gravity over the cup.

Figure 4

Figure 4

This, described in this way, may seem obvious.  It should.  Einstein’s saying that you should be able to explain physics to a barmaid has a great deal of truth to it.  The implications are what are not so obvious.

The first implication is that what Sir Nick said on CBS is not true.  You use the full circumference not by having the ball move by the edge of the cup with some speed, but reaching the edge of the cup with no speed.  (We shall complicate this in a later post just a bit, that is the essential truth of the matter.)

In or out?

In or out?

The related implication — the title of this post — is that the faster the ball is moving as it reaches the hole, the less likely it will fall even if at some point the center of mass of the ball is over the hole, not over the green.  That is, the faster we putt a ball, the smaller the hole.  The faster a putt is moving at the hole, the smaller the (effective size of the) hole.

This should be almost trivially obvious.  If a ball is moving dead straight for the center of the cup, but it is traveling at 20 miles per hour, it just isn’t/can’t/won’t drop.  One doesn’t have to consider borderline cases, like a slowly moving ball, hitting the lip of the cup.

Not quite.

Not quite.

The take away is simpler:  to make the hole as big as possible, you want the ball moving as slowly as possible at the moment it reaches the cup.

Does this completely answer our questions, to put it 17 inches past, or not?  No.  Implicitly we have assumed a flat green and failed to discuss some other variables that come into play when a putt slopes — which is almost always, not almost never.  We hope this, however, makes it clear why many of the best putters feel like it’s best to die the ball at the hole.  [3]

Sir Isaac Newton

Sir Isaac Newton

I. Newton

[1]  Lip outs.  We will append to this post at a later date a discussion, with illustrations, of what causes a lip out.  In brief, a lip out occurs when the ball travels over the edge of the cup, and begins to move down into the cup, but it’s forward velocity (or motion) across the cup is fast enough that it bounces up against the lip before falling far enough to drop.  If the ball were traveling slower but on the same line, it would drop.

[2]  Pin in the cup or pulled from off the green.  The careful reader has probably noted that the subject of when a ball will drop is not far from whether one should leave the pin in.  We discuss this in a separate post.

[3]  Other factors. While the simple model of ball, green, and ball direction in this post suggest dying the ball at the hole works best, there are other considerations that we have factored out from our discussion, in order to simplify it and make it clear, that can impact.  These include the slope of the green especially near the hole, whether the putt is uphill or downhill, and the confidence one has in how one will judge distance and deliver a stroke that leaves one with the planned or expected distance.  These factors can materially influence how any given player’s ideal way of a reading a putt is and how hard one strokes it.  As we have said, there are no absolutes in golf, or life, and the fact that a perfectly read putt on a flat green is best to die at the hole to give it the most chance of falling builds a number of assumptions in that may not, and often are not, so.

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