Most HHS readers will be familiar with the “pythagorean expectation” in baseball. That’s the concept, originally formulated by Bill James, that over time one can get a better sense of a team’s true talent level by looking at its runs scored and runs allowed (within a relatively simple mathematical formula) than at its actual win-loss record. The theory, which has well-stood the test of time and further study, is that actual win-loss records can be subject to random fluctuations in the distribution of runs across games, but that with a large enough sample to smooth out such random fluctuations those runs scored and runs allowed numbers will prevail as the the more accurate determinant of the most talented teams.
The 2012 race for the best pythagorean-expectation-based record in the AL is a tight one right now. Through last night’s games, the Rangers have (using b-ref’s version of the Pythagorean calculation) a record of 76-53, merely one game ahead of the Yankees, whose Pythag record is 75-54. You have to go back to 2005 to find a season in which an Eastern Division team failed to hold the best Pythag record in the AL. After the jump is a list of the season-by-season leaders in Pythag record in the American League during the three-division era.
If a different team than the Pythag leader had the AL’s actual best regular season win-loss record, that team appears in parentheses:
2011: Yankees
2010: Yankees (Rays)
2009: Yankees
2008: Red Sox (Angels)
2007: Red Sox (Indians/Red Sox tie)
2006: Yankees/Tigers tie (Yankees)
2005: Indians (White Sox)
2004: Red Sox (Yankees)
2003: Mariners (Yankees)
2002: Angels (Yankees)
2001: Mariners
2000: A’s (White Sox)
1999: Yankees
1998: Yankees
1997: Yankees (Orioles)
1996: Indians
1995: Indians
1994: White Sox (Yankees)
The Cardinals currently have a 1.5 game lead on the Nats for the 2012 NL Pythag standings lead, despite trailing the Nats and four other NL teams in actual winning percentage. The Cards in the NL Central are four games ahead of the Reds in Pythag terms, even as they trail the Reds by seven full games in the division standings that count.
Here are the year-by-year, league-wide Pythag leaders in the NL from 1994 on (again, the best real-world record in the league is in parens if different from the Pythag leader):
2011: Phillies
2010: Phillies
2009: Dodgers
2008: Cubs
2007: Rockies (Diamondbacks)
2006: Mets
2005: Cardinals
2004: Cardinals
2003: Braves
2002: Giants (Braves)
2001: Diamondbacks (Cards/Astros tie)
2000: Giants
1999: Diamondbacks (Braves)
1998: Braves/Astros tie (Braves)
1997: Braves
1996: Braves
1995: Braves/Reds (Braves)
1994: Expos