01 November 2013

MLB Postseason Projections 2013: BoSox, Projections Win Big

This article is part of a continuing series examining the postseason prospects of the eight seven six five four three two one remaining MLB playoff teams in 2013.

While I (begrudgingly) congratulate the Boston Red Sox for their third World Series title in ten seasons having beaten the St. Louis Cardinals, I'm also engaging in a bit of self-congratulation. By beating the Cardinals in six games, the Red Sox confirmed Rational Pastime's day-one projections. All in all, the system performed very well this year.

Wednesday's game may have been the clincher, but it was Monday's game that had the biggest impact. Game 5 sent Boston's title odds surging from 57% to 83%. While the Cardinals were still very much alive as Game 6 began, it was the previous loss that put them on life support.

The BoSox run was fairly dominant. There were twenty-three days of playoff baseball this fall (not counting play-in games), and Boston topped the WS% leaderboard in all but six of them. Read on to see just how dominant their campaign was.

The table above compiles the minimum, maximum and average WS% numbers for each team counting every day that included at least one postseason game. Obviously, the World Series winner has the highest maximum score, and it's not surprising they have the highest average probability.

What's notable is that the Red Sox low point, at 21% on October 3rd, is higher than the maximum probabilities of every other team save Detroit and St. Louis. Even more notable, their nadir occurred on a day when they had yet to even play a single playoff game. Another perspective: even the National League runners-up, the Los Angeles Dodgers, fell 3% short of the Red Sox at their highest point.

As for my model, it enjoyed a rather successful fall. The final outcome—Boston over St. Louis in six games—was the #1 projected outcome (out of a possible 128). The system projected the same outcome after the LDS and the LCS, as well. It was a very stable prediction that happened to come true.

There are a total of seven postseason series in the current format. At the start of each series, the Rational Pastime projection system picked the eventual winner in five of them. In four series, the system picked both the winner and the exact number of games. In the Tampa Bay-Boston and Los Angeles-Atlanta divisional matchups, the final outcome was the second most likely (out of six).

Even its biggest miss wasn't so bad: Detroit over Oakland in five games was the third most likely outcome at the beginning of that League Division Series.

The final Elo-based power ratings indicate that the best team won. Boston was the top-rated team from start to finish, adding .015 points during their run. St. Louis finished their campaign still tops in the National League but only third best in baseball, behind Detroit. Special mention for the Kansas City Royals who finished seventh but never played a single game in October.

I'd like to thank those of you who followed my work this postseason. I should have a few more posts up with interesting data from this postseason and my projections. Enjoy your off season!

No comments: