124th U.S. Open

Pinehurst No. 2


Edoardo Molinari conducts pretty scientific putting/flagstick experiment — and the results may surprise you

January 10, 2019

The new rule allowing golfers to leave the flagstick in while putting has ignited a debate over whether doing so provides an advantage. But while most tour pros are just talking about their decisions regarding the pin, one, Edoardo Molinari, decided to run a true experiment to determine the answer. And he got mixed results. Literally.

Molinari, the older brother of recent Ryder Cup star Francesco, enlisted three pros at his golf academy in Italy to conduct the tests. The three used a Perfect Putter, a training aid that ensures you get the same speed and line, in the experiment, which consisted of three different speeds (slow, medium, and fast) and three different lines (center, touching the flagstick, and grazing the flagstick). Molinari, a three-time European Tour winner and 2005 U.S. Amateur champ, says the three pros did 100 "putts" for each combination. Watch the video to see what happened:

And here are the two charts (one for the flagstick in and one for with it out) side-by-side:


OK, so what did we learn from all of this? As the video sums up, the experiment yielded no difference no matter what you do with the flagstick on slow putts, but distinct advantages for both options on faster putts. On the mid-speed putts, Molinari's test found taking the flagstick out was the better choice, while on the faster putts, the clear edge went to leaving it in.

Previously, the most-cited study regarding this issue came from short-game guru Dave Pelz in 1990. Pelz's tests concluded you should always leave the flagstick in—provided it's not slanting in any direction—essentially saying it's acting as a backstop that slows down a golf ball and allows gravity to pull it into the hole better.

Bryson DeChambeau certainly believes that's the case. At last week's Sentry Tournament of Champions, DeChambeau took the pin out for some breaking putts—something Molinari's experiment doesn't factor in—but left it in for the most part and led the field at Kapalua in strokes gained: putting. The performance caused Golf Channel analyst Brandel Chamblee to predict that pretty much everyone on tour will be doing it by the end of the season.

But not so fast, Bryson/Brandel. Molinari's experiment, while certainly not complete, adds a bit of fuel to the non-believers side in the debate over whether the flagstick is your friend. At least, we can safely make one conclusion: there will be more data coming on this topic.