On which basis? Cy Young is not an ERA title..if it were, Claude Osteen would have had several. Rocket could have helped avoid the recent sweep of the Astros by the Cards but wasn't good enough.
Carpenter is having the best year of the reasonable contenders(Clemens, Carpenter, Martinez, Willis).
Yeah, I saw that logic used years ago to throw away the Cy Young at some spare San Diego reliever in a year in which Nolan Ryan led the league in ERA and strikouts at age 40 but got zilch run support and thus had a so-so record. Was so bad he lost a 1-hit game and a 3-hit game (or was the latter a 2-hitter that year?) In fact there were several years where the idiot writers would hold lack of run support and win record against Ryan. Completely ludicrous that one of the 10 greatest pitchers of all time never was awarded a single Cy Young, despite earning one several times.
Within this group of six, here's how they rank in W-ERA-IP:
Carpenter: 1-2-1 = 4
Clemens: 6-1-5 = 12
Martinez: 4-4-4 = 12
Willis: 2-6-5 =13
Oswalt: 3-6-5 =14
Smoltz: 4-5-5 =14
That puts Carpenter way ahead. And I think he deserves the CY, but not by that much over Clemens, since Clemens is well ahead in ERA and has been deprived of wins because of weak offense. Either man would be deserving.
I've seen Carpenter pitch quite a bit this season (Clemens, too). All the players who see him say Carp has "electric stuff." And he does: diving, sinking fastballs; sharp late movement; complete command. Dominant and very efficient. Works late into the game, with a high number of complete games for this era.
Here is how I would rank them right now for the CY:
Carpenter: 16-4, 2.26, 171 IP
Clemens: 11-4, 1.38, 156 IP
Martinez: 12-3, 2.81, 157 IP
Willis: 15-7, 2.87, 156 IP
Oswalt: 14-9, 2.46, 171 IP
Smoltz: 12-6, 2.83, 168 IP
That's if the season were to end today. But of course, there's a whole lot of season left. Each of these guys could get ten more starts.