Originally Posted by timnz
I understand it was a relatively weak tournament between 1972 to 1982 inclusive. But from 1983 through to 1989 it had a strong field (I know there was no AO in 1986).
I certainly don't see a lot of difference from 1989 to 1990 - the latter year you give it 1.0.
Curious as to your reasoning.
Actually the change is relative to the Masters rather than the AO. I consider the Masters a great event while it was played in NY. Its decline started with the new 1990 ATP-controlled tour when it started being moved around... As at the same time the AO started consistently having all the top players participating if healthy, this is the reason for the change.
Of course this evolution was progressive on the period 1988-1995 probably, but you have to draw a line somewhere and the year of the big organizational change with the ATP take-over is a good line, I thought.