Postseason Odds

Playing the rest of the season a million times

by Clay Davenport

See the Forecast-adjusted version of this report.

Generated Sun Sep 26 07:52:13 EDT 2021


Average wins by position in AL East:  99.4 92.5 91.2 89.9 52.6
AL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Rays              96   59   .575   99.4   62.6  100.00000     .00000  100.00000         .00000    .00517
Red Sox           88   67   .528   91.8   70.2     .00000   83.30460   83.30460       -7.19978   6.91716
Yankees           88   67   .554   91.3   70.7     .00000   66.59153   66.59153        7.80084  28.87528
Blue Jays         86   69   .597   90.5   71.5     .00000   46.20868   46.20868        5.68866 -29.09233
Orioles           50  105   .392   52.6  109.4     .00000     .00000     .00000         .00000    .00000

Average wins by position in AL Central:  91.3 80.3 78.1 74.4 72.1
AL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
White Sox         87   68   .567   91.3   70.7  100.00000     .00000  100.00000         .00000    .01305
Indians           76   78   .477   80.1   81.9     .00000     .00000     .00000         .00000  -0.01300
Tigers            75   79   .441   78.3   83.7     .00000     .00000     .00000         .00000  -0.00005
Royals            70   84   .448   74.0   88.0     .00000     .00000     .00000         .00000    .00000
Twins             69   86   .460   72.5   89.5     .00000     .00000     .00000         .00000    .00000

Average wins by position in AL west:  95.1 88.8 86.8 77.6 59.3
AL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Astros            91   64   .602   95.1   66.9   99.95820     .01923   99.97743       -0.00555    .81834
Mariners          85   70   .436   88.3   73.7     .01600    3.30615    3.32215       -6.39936   2.97948
Athletics         84   71   .530   87.3   74.7     .02580     .56983     .59563         .11521 -10.50307
Angels            74   81   .466   77.6   84.4     .00000     .00000     .00000         .00000    .00000
Rangers           56   99   .397   59.3  102.7     .00000     .00000     .00000         .00000    .00000

Average wins by AL Wild Card:  92.5 91.3

Average wins by position in NL East:  86.9 84.3 76.9 68.2 66.7
NL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Braves            82   72   .555   86.6   75.4   81.79470     .01434   81.80904        2.59058  15.75874
Phillies          81   74   .514   84.5   77.5   18.20530     .02323   18.22853       -2.64017 -24.05149
Mets              73   81   .501   76.9   85.1     .00000     .00000     .00000         .00000  -0.18839
Marlins           64   90   .463   67.5   94.5     .00000     .00000     .00000         .00000    .00000
Nationals         64   91   .494   67.4   94.6     .00000     .00000     .00000         .00000    .00000

Average wins by position in NL Central:  96.2 90.0 83.7 70.0 60.4
NL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Brewers           93   62   .553   96.2   65.8   99.87975     .12025  100.00000         .00000    .00000
Cardinals         86   69   .517   90.0   72.0     .12025   99.80922   99.92947         .08519  34.96162
Reds              80   75   .496   83.7   78.3     .00000     .03297     .03297       -0.03485 -22.72922
Cubs              67   88   .412   70.0   92.0     .00000     .00000     .00000         .00000    .00000
Pirates           57   97   .373   60.4  101.6     .00000     .00000     .00000         .00000    .00000

Average wins by position in NL West:  105.9 103.5 80.6 75.0 52.4
NL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Giants           101   54   .628  105.8   56.2   88.92310   11.07690  100.00000         .00000    .00000
Dodgers           99   56   .644  103.6   58.4   11.07690   88.92310  100.00000         .00000    .00000
Padres            78   77   .517   80.6   81.4     .00000     .00000     .00000       -0.00075  -3.75125
Rockies           71   83   .476   75.0   87.0     .00000     .00000     .00000         .00000    .00000
Diamondbacks      50  105   .387   52.4  109.6     .00000     .00000     .00000         .00000    .00000

Average wins by NL Wild Card:  103.5 90.0

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.