Tom, Andy - thanks. Would you know whether or not the golden age architects of those wealthier/elite U.S. clubs consciously designed their green contours with these "higher" speeds in mind? I just don't remember ever reading the concept/concern being addressed back then.
Peter
They had less to worry about as the median speed was 6 1/2' even into the '70s. "Putting Green Angle" in the graph represents feet of slope in a one hundred foot run of ground, i.e. "5" on the P.G.A. is a green that is 5' higher at one end of a 100' run.
Peter:
There are several interesting things about this chart, and another one which I'll try to find after I make this post.
The first is that we can try to back into what green speeds must have been, by looking at the slopes on the greens. I know that the greens at Crystal Downs, which have never been changed, were designed to have holes cut in areas of up to 4 1/2 % or 5% slopes. Likewise, I know that there were places on certain greens at Merion and Oakmont and Pine Valley that were 5% or even 6%. So, if those architects made those decisions consciously, we can deduce by referring to the chart above that an architect who designed a green with a 6% slope was not envisioning a speed greater than 8 on the Stimpmeter, and that an architect who used 4 1/2 % slopes was assuming that the greens would never get above 11.
There is also another chart which shows how far the ball can be expected to roll out from the Stimpmeter at different speeds, with different percentages of slope. That one is really interesting in terms of visualizing putting ... for example, it shows that at if the green is rolling at 10 on the Stimpmeter, a ball on a 0% slope will roll 10 feet, on a 2% slope it will roll 13 or 14 feet, and on a 4% slope it may roll 32 feet! [I don't have the numbers in front of me now, but the difference is exponential.] Note, too, this literally means that if you are putting downhill on a 4% grade with the greens running at 10, the effective speed of your putt is 32!
Last but not least, note that the chart above indicates that you could still have a slope of 3 1/2 % at a Stimpmeter speed of 13 without the ball rolling infinitely ... but that most architects today stop at 3% slope [or less], and the PGA Tour insists that the hole locations on new courses have no more than 2.25% slope. Which makes you wonder how fast they anticipate getting their greens someday.