"Stimp Speed" and Synthetic Greens
by Steve Walker

President and Founder
ProGreen International, Inc.

Are you stumped by references to Stimpmeter readings? Does a golf courses' Stimp Speed reading of nine mean anything to you? The Stimpmeter is the universal device used to measure the speed of greens. The Stimpmeter was invented by Ed Stimpson, a Harvard grad and the 1935 Massachusetts Amateur champion. Decades later, the Stimp was refined by the USGA.

The Stimp is merely a 30-inch long aluminum trough raised at a 20-degree angle. A golf ball is placed in the crease of the Stimpmeter and released to roll across the green. The distance the ball rolls on the green, measured in feet and inches from the edge of the Stimp, is the speed of the green. To obtain proper readings, the USGA recommends tests be run on a level surface, with several rolls in opposite directions, and then averaged.

One of the biggest problems with synthetic putting greens used to be controlling the Stimp speed. There are two types of synthetic greens, sand-filled synthetic greens and non-infill synthetic putting greens:
Sand-Filled Artificial Greens - previously when sand-filled synthetic putting greens are first installed, the Stimp speed is slow, about a 7 or 8 on the Stimpmeter. Over an extended period of time the ball roll often becomes too fast, between 11 and 13.
Non-Sand Filled Artificial Greens - start at approximately a 10 and go up dramatically from there. There are two types of non-infilled greens, polypropylene greens and nylon greens. Polypropylene non-infilled greens have problems with the Stimp speed increasing over time because this yarn will mat down, which will yield Stimp speeds of up to 14, Yikes!

ProGreen nylon greens have the most consistent Stimp over time, and will change little or not at all over a period of time due to the fact that nylon yarn has "spring back" characteristics and our revolutionary construction design keeps the surface consistent over time. The Stimp speed will stay very close to a 9 for many years.

Why Do Stimp Speeds Vary So Dramatically? The reason the ball roll is slow on a sand-filled synthetic putting green when it's first installed is because the fibers are stiff, due to the newness of the fiber. Because the fiber is stiff, the fibers stand erect, causing increased ball roll resistance. The reason the ball rolls faster over a period of time is because the fibers loosen-up. This, combined with the surface getting hard and compacted causes the fibers to eventually bend-over and lay flat. This decreases ball roll resistance.

What has ProGreen Done to Remedy the Stimp Speed Control Problem with Sand-Filled Greens? We've been working on better ball roll control for years. We've finally come up with a putting green system that controls the Stimp speed better than any other putting green system available. First, we've increased the number of fibers. This increases the ball speed initially and slows it down over a period of time, maintaining a more consistent Stimp speed, usually between a 8 and 10. More fiber tips touching the ball as it rolls across the surface decreases the resistance when the fiber is new, and also helps to slow down the ball roll over a period of time. Secondly, to combat the ball from rolling too fast over a period a time we've made the surface softer. To accomplish this, we use a specially formulated blend of sands and our trademarked ProGreen Top Dressing™ . If the surface is softer, the fibers will not bend straight over like they will with a harder surface. This keeps the fibers more upright, causing more ball roll resistance. The size and shape of our ProGreen Top Dressing™ also helps creates resistance to keep the ball roll from rolling too fast. The composition make-up of a ProGreen Sand-Filled Putting Green System™ allows the user to vary the Stimp speed at anytime. Our Non-infill Greens are made with nylon yarn and combined with our revolutionary construction design keeps the ball roll at a consistent 9 on the Stimp Meter.