That's what I'm saying though, it is SUCH a simple idea that I'm sure it either isn't practical or has huge flaws in it. Bill James comes up with stats like that while he shits on the toilet (or otherwise ). That tells me there's some reason not to do it. Perhaps the other variables involved mean that if someone is going to go the extra step of factoring the value of OBP over SLG, you might as well start including park factors, league quality, schedule, pitchers faced, etc., and just go the whole way (at which point you're getting closer to a VORP type stat).