An optional golf rule, similar to a mulligan, allowing any shot that ends up father from the hole than it started to not be counted against a players score, on the condition that the subsequent shot be taken using a putter. It is the second shot that is called the "Greenspan Putt." Like the mulligan, its use encourages excessive risk taking, as the player is guaranteed not to end up in a place worse than where he started.
%#*! I totally misread that one. I'm gonna take a Greenspan Putt.