I'd imagine Koufax would be the real answer if we'd seen him. Ditto Gibson at his peak. Clemens has been amazing during an age that hitters dominated but if he'd pitched in the 70's he'd have just been in the same group as Ryan, Palmer, Seaver.

Clemens was clearly better than all of those three and Ryan isn't even in the same zip code as Clemens.
Oh, well. Ok then. Clemens fan much?
Not really. But I respect him very much. And he's likely the third or fourth greatest pitcher ever. And Ryan is very overrated by most people.
You've crunched the numbers and have done the analysis for this? He's not quite even the runaway best pitcher of his era let alone alltime. Do I *think* that he is? Probably but Maddux is right on his heels and Pedro was better than him during some of Clemens' best seasons. It's also pretty widely accepted that the best pitching in the modern era of baseball was Koufax from 1961 - 1966 and that the best season was Gibson's 1968 season with Pedro's 1999 season likely #2.
The legend of Clemens has grown given that he can somehow take these half seasons off and come back to pitch like he'd never left but to just claim that Clemens is #3-#4 all time is purely subjective.
Nolan Ryan "very over-rated"? That's just dumb. Looks at the peripherals between the two and you'll notice that Clemens and Ryan are damn near the same pitcher.