I think that stats, even wonkish stuff like splits and that sort of stuff, have been part of the game since the 19th century, up to and including stuff like that.
There's a very good book out called 'The Numbers Game' which is a history of stats in baseball. I've been on a baseball book binge lately and, while it is certainly a lot easier to crunch numbers w/ the low cost of computing, the numbers have been there for managers and players (who wanted to pay somebody to calcualate them...)since pretty early on in the game.