Kelsey12: They could've simply called them Championship and no one would be the wiser? I could understand the necessity to include the speed rating if there were different levels of championship green speed, but there isn't.
Ahhh, but there are different levels of green speeds within each designation. You can see it in the qualifying at Pinehurst-the green speeds are called Championship but are not the same every day. In fact, the PH greens are not true Championship speeds, rather something slower.
When tiers are mixed, such as in AS or All Players tournaments, you're going to see a hybrid speed based on the mixture. If Legends putt on a 12 and TLs putt on a 13, together they putt on something in between like 12.5, 12.6, etc. You also see this routinely change during the week in the WGT tournaments.
Players have been clamoring for this numbered green speed rating for a long time. :-)