Postseason Odds

Playing the rest of the season a million times

by Clay Davenport

See the Forecast-adjusted version of this report.

Generated Fri May 22 08:00:35 EDT 2015


Average wins by position in AL East:  93.9 87.1 81.8 76.5 69.5
AL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Rays              23   19   .534   86.2   75.8   29.57313   21.32754   50.90067        4.06003   2.23738
Yankees           22   19   .554   89.3   72.7   47.65514   18.95639   66.61152         .12247  -8.38223
Red Sox           19   22   .464   73.9   88.1    2.86258    4.04950    6.91208       -2.25071  -0.88800
Blue Jays         19   24   .511   79.1   82.9    8.42694   10.18198   18.60892        2.05714  -5.87647
Orioles           18   20   .514   80.3   81.7   11.48222   12.56053   24.04275         .00280  -9.77569

Average wins by position in AL Central:  99.7 90.5 82.5 75.8 67.6
AL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Royals            26   14   .585   97.1   64.9   66.48928   24.38550   90.87478       -0.31370   9.86692
Tigers            25   17   .554   90.8   71.2   27.48943   44.60377   72.09319        4.18479   1.08978
Twins             23   17   .468   79.0   83.0    2.98421   14.85758   17.84179         .39304   4.39814
White Sox         18   20   .441   70.7   91.3     .38453    2.81762    3.20214       -1.40160  -0.88199
Indians           17   23   .510   78.3   83.7    2.65257   13.23290   15.88547        2.13527   5.48489

Average wins by position in AL west:  92.3 84.2 79.0 74.2 67.9
AL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Astros            27   15   .534   90.0   72.0   65.96097    8.10225   74.06321       -2.52926  14.05714
Angels            21   20   .489   79.3   82.7   12.82479    8.83504   21.65983       -4.36019   6.81679
Mariners          18   22   .492   76.9   85.1    8.36822    6.17953   14.54774       -1.38764  -2.87411
Rangers           18   23   .489   76.3   85.7    7.47393    5.44742   12.92135        1.29930  -3.72306
Athletics         14   29   .522   75.2   86.8    5.37210    4.46247    9.83457       -2.01173 -11.54947

Average wins by AL Wild Card:  92.3 87.9

Average wins by position in NL East:  92.2 85.1 79.5 73.9 66.2
NL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Nationals         24   17   .514   87.7   74.3   49.06039   14.04874   63.10913       -3.04730  29.30736
Mets              24   18   .496   84.6   77.4   30.98072   15.85041   46.83113        8.75881    .20828
Braves            20   20   .471   78.6   83.4   11.46024    8.98986   20.45010        3.29538   6.80423
Phillies          18   25   .429   69.5   92.5    1.40785    1.33514    2.74298       -1.32335   1.39611
Marlins           16   26   .490   76.4   85.6    7.09081    6.15605   13.24686       -2.42971 -25.11335

Average wins by position in NL Central:  96.1 87.2 80.7 74.3 64.6
NL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Cardinals         27   14   .539   93.7   68.3   68.41788   15.88136   84.29924       -5.22617   5.63082
Cubs              23   17   .501   85.4   77.6   19.48570   26.13955   45.62525        2.94010    .06227
Pirates           18   22   .490   78.9   83.1    6.29123   13.23929   19.53053       -1.63082  -5.65207
Reds              18   22   .485   78.5   84.5    5.54350   11.24405   16.78755       -0.87060 -16.94955
Brewers           15   27   .426   66.5   95.5     .26168     .76396    1.02564       -0.75811  -0.94641

Average wins by position in NL West:  97.7 88.8 81.3 74.5 66.3
NL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Dodgers           24   16   .574   95.2   66.8   66.27908   21.58392   87.86299       -1.75613  -4.64799
Giants            23   18   .533   88.7   73.3   25.88768   38.24686   64.13454        3.33986  29.11423
Padres            20   22   .454   74.9   87.1    1.68844    6.71715    8.40559       -2.79984 -13.95991
Diamondbacks      19   21   .496   80.0   82.0    5.64786   17.28481   22.93266        1.44214  -3.67409
Rockies           15   23   .441   69.9   92.1     .49694    2.51886    3.01580         .06573  -1.57995

Average wins by NL Wild Card:  91.6 87.5

As the title says, the post-season odds report was compiled by running a Monte Carlo simulation of the rest of the season one million times. Current wins, losses and expected winning percentages are taken from the Adjusted Standings Report.

Expected winning percentages (EWP) for each team starts with their W3 and L3 from the Adjusted Standings. A regression is applied to derive the EWP for the rest of the season, which is going to be between the current winning percentage and .500. To allow for uncertainty in the EWP, a normal distribution centered on the EWP is randomly sampled, and that value is used for the remainder of the season in that iteration. To simulate the normal 4% home-field advantage, the home team gets a .020 point bonus, while the visitors take a 0.020 penalty. The likelihood of winning each game is determined by the log5 method. W and L are the team's wins and losses through yesterday's games.

Pct3 is the expected winning percentage, taken from W3 and L3, with the regression-to-mean component.

Avg W and Avg L are the average number of wins and losses each team finishes over the million season iterations.

Champions is how often, in percentage terms, this team won the championship of their division. Ties are not broken, but credited as 0.5 championships apiece (for a two-way tie), .333 apiece for a three-way tie, .25 for four-way, etc. This is why the final decimal place is not an error!

Wild Card is how often, in percentage terms, this team won the wild card. As with championships, ties are not broken, but apportioned among the tied teams.

Playoffs is how often, in percentage terms, the team either wins the division or the wild card.