gerryniswonger:
I've subtracted 10% and my putts are dropping again.
From the numbers I have, about 4% would be more appropriate:
130 % / 135 % of the putting scales.
Alas, downhill you should expect "ridiculous speed" (tm Spaceballs).
OTOH, what works that works, and the green speeds are apparently subject to day-to-day variation in the same range.