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Author: Keri Schmit

Which is the best way to putt, in or out?

In an effort to answer the debate over the flagstick and whether in or out is the best way to putt Golf Digest put it in the hands of a Ph.D., Tom Mase.

Tom Mase is a professor of mechanical engineering and former associate chair of the department of mechanical engineering at California Polytechnic State University (Cal Poly).

Mase has been on the vanguard of golf equipment research for much of his 30-plus years in academia, as well as stints at both Callaway and Titleist and as an original and long-time member of the Golf Digest Hot List Technical Advisory Panel.

His research on the value of leaving the flagstick in was precise, painstaking and perfectly clear.

His findings upend the conventional wisdom that the flagstick is some kind of backstop, gathering wayward putts back into the hole.

The facts of his study suggest the opposite, that the flagstick does much, much more to hurt your chances of a putt going in than help turn a bad putt into a made one.

The Testing

The testing was performed with a special putting device built to roll putts accurately aimed with a laser—and a true, pure roll—from two feet away. We rolled putts at different speeds hitting different parts of the pin on flat, uphill and downhill sloping greens. The test results were conclusive: You will hole a higher percentage of putts when you leave the flagstick in.

The reason for this effect is that a significant amount of energy is lost from a putt’s speed when the ball hits a fiberglass flagstick. The speed-loss enables gravity to pull the slower moving ball down into the hole more often. Even though balls have changed since my testing, holes and flagsticks have not, and the “energy-loss” effect will still win the day.

Golfers have 3 Options When Putting

Thanks to a rules change by the USGA, golfers can either remove the pin completely, have someone tend the pin, or leave the pin in and unattended. If your putt hits the pin in the third scenario, there’s no penalty (formerly two strokes or loss of hole).

It’s a major change in the name of speeding up play.

In a statement on its website, The USGA says there “should be no advantage in being able to putt with the unattended flagstick in the hole.”

It continues by saying that “In some cases, the ball may strike the flagstick and bounce out of the hole when it might otherwise have been holed,” while “in other cases, the ball may hit the flagstick and finish in the hole when it might otherwise have missed.”

But before you decide how you want to putt, let’s review some facts:

1. Assuming the pin is securely in place, standing vertical and not swaying in the wind, the hole is 4.25” wide.

2. The diameter of a standard flagstick is 0.5” (some pins taper to ¾” and even 1” above the hole).

3. If you look at the space left for a golf ball, the 2.125” half-hole minus the 0.25” half-pin, leaves 1.875” between the cup edge and the pin.

4. Golf balls are 1.68” in diameter. This leaves a .195”-gap of open space for the ball to fit into the hole with the flagstick in place.

This doesn’t sound like much space, especially if the pin is leaning slightly toward the golfer. This effect, however, has been tested

There’s a lot of science behind the research, but the studies conslucsively show that you should putt with the pin in!

To make you feel better about leaving the pin in, think about how many long putts and chips you’ve seen crash into the pin and still stay in the hole. If you’re watching golf on TV, you’ve also seen several shots fly into the hole directly from the fairway and stay in.


Leaving the flagstick in may have some benefits but from a physics standpoint, there is zero evidence to suggest that the flagstick helps in any but the rarest of situations. What the flagstick may do is occasionally reduce the length of a second putt and therefore possibly help reduce three-putts. Of course, it also will clearly and substantially reduce the number of one-putts.

Test the new rule for yourself. Putt 12 balls from a three-foot circle all the way around the hole. Do the same drill for six-foot putts. Repeat this drill 10 times on 10 different days, and keep tab of your results.

Whether or not this test makes a believer of you, you will have forced yourself to practice your putting, putting you a solid step ahead of your foursome.