Attention, sports fans: Baseball – the winning formula

MLB.com lets you customize your baseball standings. You can include (or exclude) a team’s record against the other league, against each division, at home, on the road, etc. But there’s one statistic the actuary in me really likes: expected won-loss record.

Expected win/loss records use the number of runs a team has scored and the number it has allowed and estimate the team’s winning percentage, via this formula:

Win Pct. = (Runs scored)1.82/[(Runs scored)1.82 + (Runs allowed)1.82]

Sabermetricians – the baseball geek term for baseball geeks – perfected this formula after uber-Sabermetric-geek Bill James eyeballed the formula, raising each term the power of 2. I love it because it takes all the complexities of a modern sport across hundreds of games, with runs being scored early and late, in both blowouts and nail-biters and more or less proves that to know which team is better, you just have to count up how often a team scores and how seldom its opponent does. Stuff like clutch hitting, one-run games – those are just folderol for tomorrow’s sportswriter.

For example: Tampa Bay scored 802 runs this year and allowed 649. Plug the numbers into the formula above, and Tampa is projected to win 96 games. Here are American League final standings. Notice that Tampa won, well, 96 games. Well, how about that! (h/t Mel Allen)

As expectedMost teams are within one or two games of expectation. The variation from expected losses seems to be due to chance. So Oakland, which finished with 81 wins (vs. 85 expected) was a bit on the unlucky side. Seattle finished two games ahead of expectation, though with 101 losses I guess you wouldn’t want to call them lucky.

But the National League is where it gets interesting.

Almost as expectedMost of the best teams performed about as expected (actually a little under) – except St. Louis. The Cardinals finished five games below expectations, the most dismal performance in the majors. (Houston finished eight games above expectations.) Had St. Louis won consistent with the numbers its pitchers and hitters put up, the Cardinals would have been in a one-game playoff.

A lot of agita in St. Louis this year about not making the playoffs, but this analysis tells you the breaks didn’t go the Cardinals’ way this year.

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