As Mickey Rivers once said, "Pitching is 80% of the game and the other half is hitting and fielding." While his incalculable axiom was more based in personal observation than sabermetrics, if this year's starting rotation win shares are any indication, he was right.
The top three rotations in the National League by win shares helped their teams earn playoff berths (even if one got in via the back door). And when it came to playoffs, the Houston Astros confirmed that it's better to have three A-level starters when it comes to the playoffs than to have five very good ones (see the St. Louis Cardinals). That good pitching is required for playing October games (other than charity golf matches, anyway) is no surprise, however.
So ... the report cards, please. First, a few remarks on my methodology. I decided to review pitching staffs similarly to the method I used for other positions. But because of the rotational composition of the starting staff, I also broke them down individually. To compare them across the league, I needed to designate each starter by his rank among peers. This roughly correlates to how pitchers are considered "number-one" or number-two" starters, etc., but because there's no official assignments (of which I'm aware), I used Games Started to rank them (and, in case of a tie, innings pitched). This method has its shortcomings: aces who spent time on the DL, for example, are unjustly downgraded, while middle-of-the-rotation pitchers who happened to start a lot of games had to stack up against top-flight pitchers. For teams like the Cardinals, who essentially had one #1 starter and four others, it makes less difference (though free agent Matt Morris is likely to command more than just "fifth-starter" dollars this offseason, to be sure). Unlike the other "position" grades, report cards for starting pitchers are for individual players and not group performances. I did, however, include a win shares total for each team's starting five, as dictated by games started, then graded on a bell curve.
The first thing that may jump out at you is that the Senior Circuit's Cy Young winner did not receive an A. In fact, he didn't even earn a B+. Believe me, I did a double-take and then a double-check on my numbers, too. But let's first remember that overall win shares are comprised of three sub-categories of win shares: fielding, batting and pitching. Pitchers don't get credited with fielding WS, but they do earn batting WS. Typically, this hurts them, since because of their inferior lumber skills, they generate negative win shares for their teams. As you might expect, Dontrelle Willis is an exception, actually producing 0.7 WS to the positive. But as much as batting WS hurts Carpenter (to the tune of -4.2), even strictly using pitching WS, Carp is only the fourth-best in the league. More evidence of the shortcomings of Win Shares? Maybe. I'm merely the proctor of this exam: I don't make the curriculum, I just give the grades. Then again, it's hard to argue with Oswalt, Pettitte and Clemens getting straight A's.