Now that Major League Baseball’s regular season has ended with the wild wildcard win by the Kansas City Royals over the Oakland A’s and with the Pittsburgh Pirates being eliminated by the San Francisco Giants, I've once again begun analyzing the probability of each team advancing through each round of baseball’s postseason.
The Los Angeles Dodgers (71%) and the Washington Nationals (68%) have the greatest chance of advancing to the National League Championship Series going into their first Division Series games. The Kansas City Royals (61%) and Baltimore Orioles (64%) after winning the first game of their Division Series have turned themselves from underdogs into favorites.
Image of Andrew McCutchen: Credit: RJ Schmidt, Flckr. CC BY-ND 2.0
Each year, at the season’s start, I project the number of wins each team should earn. Back in March, my model picked 7 of the 10 post-season teams, a result as good or better than most of the experts at Yahoo Sports, Sports Illustrated, ESPN etc. My method uses a Markov process approach, originally published in the journal Operations Research, and it enables one to assess prospective trades and evaluate who should win the Most Valuable Player and Cy Young Awards among various other applications.
| Team | Game 1 | Game 2 | Game 3 | Game 4 | Game 5 | |||||
| Starter | P(win) | Starter | P(win) | Starter | P(win) | Starter | P(win) | Starter | P(win) | |
| DET-Tigers | Scherzer | 0.494 | Verlander | 0.456 | Price | 0.618 | Porcello | 0.568 | Scherzer | 0.494 |
| BAL-Orioles | Tillman | 0.506 | Chen | 0.544 | Gausman | 0.382 | Norris | 0.432 | Tillman | 0.506 |
| KCA-Royals | Vargas | 0.430 | Ventura | 0.375 | Shields | 0.593 | Guthrie | 0.405 | Vargas | 0.430 |
| ANA-Angels | Weaver | 0.570 | Shoemaker | 0.625 | Wilson | 0.407 | Rasmus | 0.595 | Weaver | 0.570 |
| SLN-Cardinals | Waiwright | 0.336 | Lynn | 0.378 | Lackey | 0.462 | Miller | 0.528 | Wainwright | 0.336 |
| LAN-Dodgers | Kershaw | 0.664 | Greinke | 0.622 | Haren | 0.538 | Hernandez | 0.472 | Kershaw | 0.664 |
| SFN-Giants | Hudson | 0.357 | Petit | 0.464 | Vogelsong | 0.431 | Bumgarner | 0.530 | Hudson | 0.357 |
| WAS-Nationals | Zimmerman | 0.643 | Strasburg | 0.536 | Roark | 0.569 | Gonzalez | 0.470 | Zimmerman | 0.643 |
For the series, we have the following probabilities of winning each match-up:
| Win in 3 | Win in 4 | Win in 5 | P(win series) | ||
| American League | Tigers vs.Orioles | ||||
| Tigers win | 0.139 | 0.224 | 0.186 | 0.549 | |
| Orioles win | 0.105 | 0.156 | 0.190 | 0.451 | |
| Royals vs. Angels | |||||
| Royals win | 0.096 | 0.142 | 0.161 | 0.399 | |
| Angels win | 0.145 | 0.243 | 0.213 | 0.601 | |
| National League | |||||
| Cardinals vs. Dodgers | |||||
| Cardinals win | 0.059 | 0.148 | 0.122 | 0.330 | |
| Dodgers win | 0.222 | 0.2-7 | 0.242 | 0.671 | |
| Giants vs. Nationals | |||||
| Giants win | 0.071 | 0.162 | 0.132 | 0.365 | |
| Nationals win | 0.196 | 0.201 | 0.238 | 0.635 |
On my website, I provide the likelihood of each team taking the series in a given number of games. These numbers are revised as the probabilities change with the progression of each series.
During the season I also apply the model to determine whether it is worthwhile to wager on games each day during the baseball season. My picks have led to positive results for 9 of the 14 years (counting 2014’s thus far somewhat disappointing performance) he has been doing this.
My MVP and Cy Young results and the updated method to produce them have appeared in the International Journal of Performance Analysis in Sports. The model computes the probability of a team with given hitters, bench, starting pitcher, lineup, relievers scoring any number of runs along with home field advantage to compute the chance each team has to win a game.
My model also tied for first this season at Baseballphd.net’s annual contest to pick the teams who would make it to the playoffs.after being the sole winner 3 times from 2010-2013.
