Last year, I came up with an excitement index to evaluate how good a baseball post-season was. The system isn’t exactly scientific, but it does provide some insight. It works like so:

Every game played gets 1 point.

Each game get 0.2 extra points for a lead change or tie. So tonight the Sox led 1-0. The Tribe tied it. Then the Sox took the lead for good. 0.4 points. Now if the Tribe had scored a run in the 1st and another in the second, that would have been 0.4 points; but had they taken the lead with two in the 1st, that would have only been 0.2 points. The system rewards a little drawing out of the game.

Extra innings or a last at-bat victory is worth an extra 0.5 points.

Finally, the game is credited with 1/(margin of victory). So a 1-run game gets an extra point. A five-run game only gets 0.2 points.

It’s arbitary, I know. It gives the same weight to an 18-inning game as a 10-inning game. It weights early rallies as much as late ones. It doesn’t account for runners left on base, which is why Game 7 of the 1991 World Series comes in at only 2.50. It weights an exciting game one as much as an exciting game seven. It doesn’t care if a team has come back from being down 3-0.

In other words, it’s quick and dirty.

I’m not really looking to rank the greatest game in baseball history. What I’m looking for are series — and post-seasons full of series — that go the distance with lots of exciting close games. And I don’t have the computer resources to do a more thorough job. This one can be calculated just by looking at the line score.

Here’s a list of season-by-season excitement indexes in the wild card era:

1995 – 66.20
1996 – 62.06
1997 – 66.86
1998 – 53.07 (all-time great teams make boring playoffs)
1999 – 60.83
2000 – 56.35 (subway series; ugh)
2001 – 62.13
2002 – 61.48
2003 – 74.12 (WOW! See the linked post.)
2004 – 65.42
2005 – 57.37
2006 – 49.84
2007 – 47.62

Last year was the boring post-season of the wild-card era. We had no less than five series sweeps. The Cleveland-New York DS went four games. The only decent series was the Boston-Cleveland LCS and that was only because it went 7 games. It was the dullest 7-game series in history.

So this season? So far, it’s 49.20. So it’s already matched the excitement of the last two post-seasons. The Red Sox-Rays series that just finished was the most exciting since the 2001 world series (although the 2004 NLCS comes close). Game 2 was an utter classic for the ages, one of highest single-game score in the database. Games five and six were also highly exciting. The score of 14.94 was the fourth highest since 1991, being topped only the 1991, 1992 and 2001 world series. I know it was that good because I could barely watch (I was pulling for the Rays).

Given the mean score of a seven-game series (10.97), we can expect a score for 2008 of about 60. This is almost exactly the average in the wild-card era.