Now you have me curious. ESPN goes back to 2000:
Mike Mussina, 34 starts, 237.2 IP - almost 7
David Wells, 35 starts, 229.2 IP - 6.5
Kenny Rogers, 34 starts, 227.1 IP - 6.7
Brad Radke, 34 starts, 226.2 IP - 6.7
Sidney Ponson, 32 starts, 222.0 IP - almost 7
On the other hand:
Roger Clemens, 1987, 36 starts, 281.2 IP - almost 8 innings a start
I think I should change my criteria because an "average" is tricky. Sometimes the game is a blow out and the ace is removed early. Some games are at the end of the season and the ace is purposefully rested. Maybe I should just rank #1-#5 starters on percentage of quality starts. Maybe:
#1 starters: 75% quality
#2 starters: 65% quality
#3 starters: 50% quality
#4 starters: 40% quality
#5 starters: 25% quality