The two pitchers are inseparable, and despite Lee leading Halladay in essentially every category, there is reason to question whether or not Lee is deserving to be rated ahead of Halladay.
Joe Sheehan at Baseball Prospectus first proposed the idea of rating Halladay over Lee. His theory was that Halladay's schedule had been substantially more difficult then Lee's. This is something I had never truly considered prior to reading Sheehan's article, but clearly this is relavent information.
Cliff Lee has made 28 starts this season, Roy Halladay 29. Of those, 13 are in-common starts: the A’s, Rays and Rangers twice, and the Angels, White Sox, Reds, Royals, Twins, Yankees and Mariners once. Those starts cancel out. Of the remaining starts, there seems to be a very wide gap in the calilber of competition, enough to at least mention. Of the 15 starts Cliff Lee does not have in common with Halladay, nine have come against teams in the bottom third in offense, as ranked by team EqA, and none have come against a team ranked in the top six.Wouldn't you agree that is substantial? Wouldn't that be like not adjusting a hitter's stats that were inflated by an extremely favorable hitting environment?
Looking at it from the other direction, Halladay does not have a single not-in-common start against a team ranked below 18th in EqA. So of the 15 (in Halladay’s case, 16) not in common starts between the two, 60% of Lee’s have come against offenses worse than any of Halladay’s. Halladay also has four not-in-common starts (one against the Cubs, three against the Red Sox) better than any of Lee’s.
Let me run the data this way, because I think it illustrates the point. The following numbers are the team EqA ranks for each not-in-common opponent, highest to lowest.The argument becomes substantial. However, individuals may slightly discredit it, by taking a lazy approach, looking at the 'similar opponents' and grouping them together. One writer, debated me at BDD using this lazy approach.
Halladay: 3, 4, 4, 4, 9, 9, 9, 11, 11, 14, 14, 14, 14, 17, 18, 18
Lee: 7, 7, 7, 12, 13, 13, 21, 22, 22, 25, 26, 27, 28, 28, 28
It helps if you read those numbers right to left. It’s clear from this data that Cliff Lee has seen a significantly inferior set of opponents than Halladay has.
His theory was, for example, that 6 'common' starts are the same no matter who the common starts are. While anyone with a moderate amount of intelligence can understand that if one pitcher throws 5 games against the Yankees and 1 against the Royals it is vastly more difficult then 5 games against the Royals and 1 against the Yankees. This doesn't even account for the enormous deviations in hitter friendly environments that exists.
What that lazy analyst should have done, is the following:
Halladay faced the following teams in common:
- Boston 5 times
- Kansas City once
- Minnesota once
- New York Yankees 6 times
- Seattle once
- Tampa 5 times
- Texas once
- Five times
- Four times
- Boston Red Sox - 5.22
- Kansas City Royals - 4.27
- Minnesota Twins - 5.13
- New York Yankees - 4.87
- Seattle Mariners - 4.14
- Tampa Bay Rays - 4.78
- Texas Rangers - 5.56
The next step is to multiply the games played by the amount of runs per game. I separated Halladays starts from Lee's and found:
- Halladay faced 12 'similar' games against teams with a cumulative 4.96 runs per game,
- Lee faced 9 'similar' games against teams with a cumulative 4.69 runs per game.
Thus, despite the writers assertion that Lee fared better then Halladay against similar opponents, the writer failed to discover that Lee had a substantially easier similar opponents schedule.
While Sheehan's analysis is excellent and provides quite the step towards arguing for Roy Halladay, his analysis assumes that Halladay was facing the best Red Sox lineup everytime he went out there. While my procedure takes a similar shortcut, we can utilize Baseball Prospectus' database to tell us who faced more difficult batters.
According to BP's "Opponent's Quality, On Base Plus Slugging Average (OQO) is the aggregate on base plus slugging average of all batters faced by a pitcher..." We can use this tool to figure out who regularly faced tougher opponents.
In the American League, among starters with at least 200 innings pitched during the 2008 season, Roy Halladay had the most difficult OQO of .766. Ranking last out of 15 pitchers was, guess who, Cliff Lee, posting an OQO of .735.
In other words, we're talking the difference in Felipe Lopez and Yunel Escobar. By show of hands, if you were to pick one of those hitters to face for every at bat of a season, which one would you take over the other?
While this certainly should not entirely discredit what Lee accomplished this season, it does go to show that one must utilize some perspective when selectiving the leagues best pitcher. It is because of this perspective that Cliff Lee is the inferior pitcher to Roy Halladay in the American League.