Originally Posted by mattennis
I know the official statement is that Wimbledon's grass change was from 2001 to 2002 (so that 2002 was the first with different grass), but already in 2001 most players were playing from the baseline as you can see here: https://www.youtube.com/watch?v=6Ry7ZCCh5uI
There were actually at least 2 changes made to the grass at Wimbledon. One was that the type/composition was changed. Another change was made to how the grass was cut. Do not know if these were both made at the same time.
Other changes were also instituted, possibly in the late 90s. The Slazenger balls used for the W tournament were made brighter -- easier to see in order to take some advantage away from big servers (& returners). The cans used for the tournament are opened the day/night before they are used, I believe. This would reduce the pressure somewhat make the ball slightly softer and slower (at the bounce). I do not know when this practice started. It is also possible to manufacture the ball with slightly less pressure or bounce.
I do not know if it was done, but it is also possible to slow down the ball slightly (as it moves thru the air) by increasing the amount of felt -- this increases air drag.