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. It’s also clear from our research that the fiberglass type of flagstick is the least detrimental (but still nowhere near as good as taking the flagstick out). Finally, there is some evidence that tour players putting on really fast greens may benefit slightly because the ball may be rolling slower as it comes in contact with the pin. This benefit however remains miniscule compared to the benefit of pulling out the flagstick completely. Perhaps the best benefits to leaving the flagstick in are the optics and distance perception. Several sports vision experts we contacted suggested there would be such benefits especially from longer distances, and noted putting instructor Mike Shannon said his research suggested players read greens better because the flagstick acted as a plumb line. So the obvious solution might be to have the flagstick attended. In other words, a return to the preferred method from before the new rule was enacted. We shall see if tour players will see this data and change their minds.