It is, however, one piece that all of us look down upon. The popularity of these kinds of spikes on the PGA TOUR has blossomed in the last three years. Improved course conditions are a factor for low scoring. There is no doubt that greens on the PGA TOUR are getting better, but good agronomy is only a part of the reason. Non-metal spikes do not penetrate into the grass like metal spikes.
Penetration is what causes spires of grass to rise up as the foot moves off the grass.
These are called spike marks and they can knock a putt off line. It is against the rules for a player to stamp them down before putting. But with less metal cleats on TOUR, putting surfaces are smoother, and it's having an effect. Here are some numbers to consider. Through the first 10 events this year, the TOUR average for putts on a green hit in regulation is 1.766.