I wanted to post this quick follow-up chart, which lists each pitcher's runs allowed per nine innings, innings pitched per start, hits and strikeouts per nine and strikeout-to-walk ratio, all rated as to how much better they were than the league average for that season. (Totals are not park adjusted.)
A few notes. Gaylord Perry and Zack Greinke probably have the shakiest ground to be on the list. Depending on the importance you want to place on the various numbers, Greinke's relative lack of stamina and Perry's relative lack of dominance in strikeout rate and strikeout/walk ratio hurt them. Perry was amazingly durable that season, throwing 342 innings, so his WAR (wins above replacement) was very high. But it was a low-scoring era and a lot of starters pitched deep into games that year, so Perry's innings per start, while still high, didn't necessarily tower over the league.
Greg Maddux probably deserved to be ranked higher. I didn't put him as high since he only made 28 starts in the strike-shortened season, but I rated Pedro's two 29-start seasons higher. Maddux didn't dominate like Pedro did with the killer strikeout rates, but he did dominate in his own way. I think you could also make the case the Roger Clemens' 1997 and Dwight Gooden's 1985 seasons were incrementally more impressive than Bob Gibson's 1968.
Anyway, that's the fun thing on a list like this. I don't think there a right answer, but it's fun defending your choices.
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