Golf_Digest_USA_-_May_2019

28 golfdigest.com | may 2019

Play Your Best Golf Digest Tested

new rule this year allowing golfers to putt with the

flagstick in without incurring a penalty is generating

serious debate among pros and amateurs. The USGA

made the change to help speed up play, but some tour players

are leaving the flagstick in because they believe it helps them

make more putts. Is this true? USGA officials say the new

rule “wasn’t based on research but how the game is played.”

So Golf Digest asked if I would help them bring some clar-

ity to the issue. Using the golf teams at California Polytech-

nic State University, plus a lot of physics, engineering and

statistics, I methodically analyzed how a putted ball inter-

acts with a flagstick. After numerous tests with real golfers,

machines and multiple types of flagsticks, the data is clear:

Leaving the flagstick in hurts a putt’s chance of being holed

much more often than it helps hole putts that otherwise

would not have gone in. Only in the rarest of cases is a flagstick

going to “catch” a missing putt and drop it in the hole. Even

the most highly skilled putter—given standard deviations—

is going to hit the flagstick dead-center only 27.6 percent of

the time. For that remaining 72.4 percent, the golfer isn’t hit-

ting the pin straight-on, and it’s always a disadvantage for

making putts in these instances. —with mike stachura

tom mase, a member of the Golf Digest Technical Panel,

is a professor of mechanical engineering at California Polytechnic

State University. He has spent more than 30 years in academia

and in golf research and development. He was co-captain of the

golf team at Michigan State in 1980.

THE METHODOLOGY

▶ The testing involved

college golfers and the

Perfect Putter training aid

at the Cal Poly golf-team

practice facility at Dairy

Creek Golf Course. Using

the Perfect Putter, putts

were rolled for straight-on

and off-center impacts and

at multiple speeds that

ended up 2.5 feet, 4.5 feet

and up to 12 feet past the

hole. All scenarios were

tested in random rounds

of 30 putts each.

THE NUMBERS

▶ For putts rolling 2½ feet

by the hole, putts aimed

to hit the flagstick dead-

center or off-center went in

the hole every time—with

or without the flagstick in.

For putts rolling 4½ feet by

the hole and aimed to strike

the flagstick off-center, 90

percent of putts were holed

without the flagstick in. Only

45 percent were made with

the flagstick in.

A

▶ see full testing methods

at golfdigest.com/go/flagstick.

Take the Flagstick Out!

On putts, the pin hurts more than it helps

by tom mase, ph.d.