Right, I'm picking pitchers that all pitched a qualified number of innings. There are 88 of them. Their range of value and amount success is widely varying and does not really correlate to IP (except at the fringes, and there are even exceptions at the top end: Clayton Richards). Thus, how could it be the most important statistic when it doesn't even relate to how successful a pitcher was in THAT season? Cherry picking Diamond was an interesting choice. Diamond ranked 80th in IP, or the bottom 10%. Would you say 90% of the pitchers on the list were better than he was? Picking any other stat gives us a much better picture of his actual value and success. In WAR he ranked 45th. In ERA, he ranked 31st, xFIP: 42nd, K/9 86th, BB/9 4th, HR/9: 31st. So, his IP was only close in ranking him as a pitcher to his K/9, but everything else he was in the top half. So, if IP is actually the worst at showing you what kind of year he had, how can IP be the most important stat? I'd never advocate picking one stat, and you obviously have to consider IP when looking at stats to make sure they aren't flukes or small sample sizes, the same way you would with PA for hitters, as it gives context, but that is all. Again, except for the edges (Verlander, etc..), but it's a ridiculous stat to call the most important.