USGA(?) approximate score

[metallion]

This may seem stupid, but I have recently found myself searching for facts on this topic without finding anything:

I recall reading somewhere that USGA(?) ran a statistical study that determined that the amateurs score for 18 holes will typically 96 subtracted by the number of greens hit times 2 - or something like that.

Anyone remember the exact result of the study, who conducted it and maybe posess a link?