I dunno about the four man rotation. I'll buy the argument that maybe you should do it in the minors to protect prospects, but having 8 starter-like pitchers isn't feasible in the majors for obvious reasons.

Also, he argues that the best pitchers need to pitch deep into games that aren't close just so they can get to 220 or 230 pitches for the season, but number of innings pitched isn't what's important -- it's number of wins. I'd pitch Randy Johnson into the 8th, even in a blowout, and that way 1) I'm assured a win this game and 2) I have a fresh bullpen for next game.

He still doesn't address the simple argument that a lot of normal pitchers might get hurt with one fewer day of rest. You put a lot of stress on the bullpen when you need to stick to low pitch counts, and it's nice to be able to have your pitcher go the distance now and then to help the bullpen out. My guess is that in real game situations the bullpen flexibility lost when you go to the four man rotation and the importance of keeping starters healthy overcome the greater pitching quality among starters you get with it.

Lastly, teams used to use four man rotations and now they don't -- I don't think they're as stupid and stubborn as this guy suggests. Managers have reasons for the things they do and even though very few teams have quality fifth starters, they all see fit to give them starts. Just saying "this is the way things worked in the 80s" isn't much of an argument because nowadays the reality is that you're gonna have weak pitchers somewhere, and you don't want them to be stuck in there for three innings because you don't have anyone else to bring in.