Postseason Odds

Playing the rest of the season a million times

by Clay Davenport

See the Forecast-adjusted version of this report.

Generated Fri Sep 24 07:52:18 EDT 2021


Average wins by position in AL East:  98.6 93.1 91.2 89.5 52.7
AL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Rays              94   59   .571   98.6   63.4   99.67308     .32692  100.00000         .00000    .01280
Red Sox           88   65   .529   92.8   69.2     .31283   92.87137   93.18420        1.59298  28.84431
Yankees           86   67   .552   90.3   71.7     .01253   42.56398   42.57652        6.32916  -4.37736
Blue Jays         85   68   .596   90.7   71.3     .00155   58.53568   58.53723      -10.82038 -23.64553
Orioles           49  104   .394   52.7  109.3     .00000     .00000     .00000         .00000    .00000

Average wins by position in AL Central:  91.5 80.3 78.1 74.3 71.9
AL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
White Sox         86   67   .570   91.5   70.5  100.00000     .00000  100.00000         .00235    .02322
Indians           75   77   .473   80.0   82.0     .00000     .00000     .00000       -0.00235  -0.02247
Tigers            74   78   .439   78.3   83.7     .00000     .00000     .00000         .00000  -0.00088
Royals            69   83   .450   74.0   88.0     .00000     .00000     .00000         .00000    .00000
Twins             68   85   .459   72.3   89.7     .00000     .00000     .00000         .00000    .00000

Average wins by position in AL west:  96.2 88.5 85.9 77.7 59.2
AL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Astros            91   62   .607   96.2   65.8   99.98195     .01035   99.99230         .00521    .34673
Mariners          84   69   .442   88.3   73.7     .01175    5.46847    5.48022        3.23920   4.83762
Athletics         82   71   .522   86.1   75.9     .00630     .22323     .22953       -0.34617  -6.01839
Angels            73   80   .460   77.7   84.3     .00000     .00000     .00000         .00000  -0.00003
Rangers           55   98   .395   59.2  102.8     .00000     .00000     .00000         .00000    .00000

Average wins by AL Wild Card:  93.1 91.3

Average wins by position in NL East:  86.4 83.5 77.8 69.2 67.4
NL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Braves            80   71   .554   86.2   75.8   81.84318     .20296   82.04614       -7.93935  -1.52346
Phillies          79   74   .512   83.8   78.2   18.15378     .45332   18.60710        7.16194  -5.21411
Mets              73   79   .505   77.8   84.2     .00303     .00000     .00303         .00044  -1.40319
Marlins           64   88   .468   68.3   93.7     .00000     .00000     .00000         .00000    .00000
Nationals         64   89   .496   68.3   93.7     .00000     .00000     .00000         .00000    .00000

Average wins by position in NL Central:  95.3 88.6 82.8 71.4 61.1
NL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Brewers           91   62   .549   95.3   66.7   99.69680     .30320  100.00000         .00000    .00003
Cardinals         83   69   .513   88.6   73.4     .30320   98.63898   98.94218        2.43753  49.73126
Reds              78   75   .495   82.8   79.2     .00000     .36508     .36508       -1.65367 -26.69135
Cubs              67   85   .416   71.4   90.6     .00000     .00000     .00000         .00000    .00000
Pirates           57   95   .377   61.1  100.9     .00000     .00000     .00000         .00000    .00000

Average wins by position in NL West:  105.4 103.7 81.0 75.8 51.9
NL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Giants            99   54   .626  105.0   57.0   68.35665   31.64335  100.00000         .00000    .00000
Dodgers           98   55   .647  104.1   57.9   31.64335   68.35665  100.00000         .00000    .00000
Padres            77   75   .518   81.0   81.0     .00000     .03648     .03648       -0.00688 -14.89907
Rockies           71   81   .478   75.8   86.2     .00000     .00000     .00000         .00000  -0.00010
Diamondbacks      49  104   .386   51.9  110.1     .00000     .00000     .00000         .00000    .00000

Average wins by NL Wild Card:  103.7 88.7

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.