This is a continuation of the serialization of "The Great Pennant Race Abstract" from the book It Ain't Over 'Til It's Over: The Baseball Prospectus Pennant Race Book.
Many readers will be interested in which pennant races in the last few years rank the highest and so here are the top 10 races since the dawn of the new millennium.
Rank Year Lg Div Score Teams Winner
1 2007 NL West 32.7 3 Arizona Diamondbacks (90-72)
2 2004 AL West 31.8 3 Anaheim Angels (92-70)
3 2002 NL West 30.0 3 Arizona Diamondbacks (98-64)
4 2005 AL East 28.0 2 New York Yankees (95-67)
5 2004 AL East 27.9 2 New York Yankees (101-61)
6 2006 AL Central 27.0 2 Minnesota Twins (96-66)
7 2002 AL West 26.2 2 Oakland Athletics (103-59)
8 2000 NL East 25.0 2 Atlanta Braves (95-67)
9 2001 NL Central 24.0 2 Houston Astros/St. Louis Cardinals (93-69)
10 2007 AL East 22.9 2 Boston Red Sox (96-66)
The most recent race to make the list is of course the excellent 2007 NL West race between the Diamondbacks, Padres, and Rockies thanks to the improbable heroics of the Rox. But just two years ago, the 2006 AL Central race was very tight as the Tigers, after leading the division for almost the entire season, were passed by the Twins on the season's final day as the Tigers fell in twelve innings to the lowly Royals as the Twins beat the White Sox.
The 2004 AL West race takes the second spot and the 38th overall as the Anaheim Angels finished one game in front of the A's and three games ahead of the Rangers. The Angels took matters into their own hands by beating the Rangers three out of four and the A's four out of six to close the season. Although the Diamondbacks in the 2002 NL West race were in sole possession of first place after July 15th, the race scores well since it tightened in the final week before Arizona swept a 4-game series with the Rockies to end the season and win by just 2.5 games over the Giants.
The unbalanced schedule since the introduction of divisional play coupled with the fewer number of teams per division - especially since 1995 and the addition of two more divisions - makes it a bit more difficult for modern races to rack up really high Race Scores. When you consider that 176 of the 312 races occurred since the inception of divisional play in 1969, and yet only 12 of the top 50 races but 28 of the next 50 are from this period, you can see how the calculation of the Race Score favors the past. Traditionalists will no doubt agree that this is the way it ought to be.