Originally Posted by Huisj
Well there you have it, look no further than ERA+ and pWar for the absolute info on how good someone has been and will be!
If ERA+ is the end all be all, why does ERA have a surprisingly low year-to-year correlation compared to other stats that are much less prone to large fluctuations?
Because it's not a prediction stat, it's relative to how good a player is right now. ERA+ takes performance and adjusts to make all outside factors even. If you want correlation for future seasons, you don't use ERA+. I used ERA+ because it's past performance that Lincecum is being signed for, and ERA+ is the most unbiased measure of recent performance.