You could make a similar case that Lester has literally been all the pitching. The Red Sox have 9 postseason wins, and he has 4 of them. The only game he has lost was a 0-1 game. Compare his postseason to guys like Price, Wainright, Kershaw, the "bonafide" aces, and it shows how impressive he has been. Hell, look at the failures of Peavy and Buchholz, and it shows just how important he has been to this team. Did I mention that Detroit and St Louis were #2 and #3 in runs scored in the regular season?
If Ortiz wins the MVP -- which would be similarly well-deserved -- he needs to go to trophys.com and order Lester a World Series Cy Young, because what he has done is nothing short of masterful.