CC Sabathia won his 19th game last night, leaving him one win short of Josh Beckett and tied with several other pitchers. In an era of specialized relievers and pitch counts, wins should have become an anachronism, but they still confer a perceived honor that most other statistics can't approach.
So how to translate a simple win-loss record into a more meaningful record of pitcher's performance? Let's start with the most basic tenant of pitching: run prevention.
Runs Allowed
In order to get credit for a win, you must allow fewer runs than your team scores. The best pitcher in a given year should be the one who allows the least amount of runs, assuming all pitchers pitch the same amount of innings. Since a cumulative comparison of runs allowed is going to favor the pitcher who pitches the least amount of innings, runs allowed divided by nine innings pitched, or more simply called Run Average (RA) is a more accurate way of directly comparing pitchers.
Here are the RAs of the main competitors for this season's AL Cy Young:
Fausto Carmona 3.27
Josh Beckett 3.41
John Lackey 3.50
CC Sabathia 3.51
Johan Santana 3.62
RA counts all runs given up by a pitcher scored by runners he allowed to reach base, including unearned runs. Because unearned runs are thought to not be a pitcher's fault, the more accepted run average measure is Earned Run Average, or ERA (difference from RA in parentheses).
John Lackey 3.01 (-.49)
Fausto Carmona 3.06 (-.35)
CC Sabathia 3.21 (-.30)
Josh Beckett 3.27 (-.14)
Johan Santana 3.33 (-29)
Beckett has the smallest difference between runs and earned runs, which makes sense given how good Boston was in making outs out of balls put into play. There is a school of thought, though, that pitchers are in some way responsible for even unearned runs, in which case Beckett would get more credit than Sabathia in the runs allowed department.
Even if you remove defense from the equation, Beckett comes out on top. Fielding Independent Pitching is a statistic that measures "all those things a pitcher is responsible for."
Josh Beckett 3.22
CC Sabathia 3.27
John Lackey 3.66
Johan Santana 3.96
Fausto Carmona 4.05
Innings Pitched
Besides providing value to the team by preventing runs from scoring, pitchers also help their clubs by simply staying on the mound. Physical stamina , pitch efficiency, and knowing how to get the same hitters out 3 or 4 times a game are key ingredients to being able to pitch deep into games, and this ability adds a positive dimension to a starting pitcher. The seventh and eighth innings that a starter pitches reduces innings that a team's primary setup men have to pitch, and over the course of a season, keeps a bullpen rested and healthy.
CC Sabathia 241.0 (7.08 IP/G)
John Lackey 224.0 (6.78 IP/G)
Johan Santana 219.0 (6.63 IP/G)
Fausto Carmona 215.0 (6.71 IP/G)
Josh Beckett 200.2 (6.69 IP/G)
Beckett missed three starts this season, while Fausto Carmona missed a start early in the season after he was optioned to the minors. The other three made their full complement of starts. This is where Sabathia's case can be made: he pitched by far the most innings in the AL, and went deeper into games on a per-game basis than any other contender.
Somewhat related to innings pitched is the Hardball Times statistic, Pitching Runs Created, an equivalent to the offensive Runs Created. It is a cumulative statistic, so those with more innings pitched, all things being equal, will come out on top:
CC Sabathia 131
Johan Santana 124
Josh Beckett 119
John Lackey 118
Fausto Carmona 116
What about peripherals?
If the Cy Young Award is given to the most impressive-looking pitcher, then yes, we should pay close attention to home runs allowed, walks allowed, and strikeouts. But since the award is given to the most effective pitcher, peripherals are more window dressing than the foundation of a pitcher's candidacy. But for what it's worth:
Strikeouts/Game
Johan Santana 10.3
Josh Beckett 9.1
CC Sabathia 8.3
John Lackey 7.5
Fausto Carmona 6.0
Walks/Game
CC Sabathia 1.5
Josh Beckett 1.9
John Lackey 2.2
Johan Santana 2.3
Fausto Carmona 2.7
Home Runs/Game
Fausto Carmona 0.70
John Lackey 0.75
CC Sabathia 0.79
Josh Backett 0.80
Johan Santana 1.45
So who should win?
It really depends on your pitching philosophy. If you gravitate towards rate statistics, Josh Beckett's your man. If you appreciate a pitcher who goes deep into games, Sabathia's your candidate. I personally feel that the 40.1 inning advantage Sabathia has over Beckett makes up for Beckett's superior run prevention numbers. Whatever the case, any distinction between the two should not be based on wins or win percentage, neither of which shows much correlation to actual effectiveness.