Postseason Odds

Last update: Thu Jul 2 07:31:00 2009 PT



Playing the rest of the season a million times

by Clay Davenport

See the PECOTA-adjusted version of this report. As well as the ELO-adjusted version of this report.

Generated Thu Jul 2 07:16:25 EDT 2009


Average wins by position in AL East:  98.2 93.2 88.7 81.8 70.5
AL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Red Sox           48   30   .568   94.7   67.3   42.33338   32.43156   74.76494        1.95975  -7.45504
Yankees           45   32   .569   91.5   70.5   23.46939   28.32392   51.79332        3.53673  18.53931
Rays              44   36   .606   92.5   69.5   32.03336   28.55096   60.58432       -6.73926  10.65874
Blue Jays         42   38   .536   82.7   79.3    2.15372    5.70586    7.85958        1.72145 -18.22792
Orioles           35   43   .464   70.8   91.2     .01016     .05301     .06317       -0.03405  -0.34564

Average wins by position in AL Central:  88.6 83.5 79.1 73.3 67.4 88.7
AL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Tigers            43   35   .494   83.9   78.1   36.04286     .77720   36.82006       -6.54045 -15.09403
Twins             41   39   .525   84.5   77.5   40.79708     .75846   41.55553        3.42929   4.06969
White Sox         40   38   .507   81.5   80.5   21.14450     .60211   21.74661        3.81946  14.77917
Royals            33   44   .481   72.2   89.8    1.48868     .02146    1.51014       -0.42844  -2.09356
Indians           31   49   .477   69.9   92.1     .52688     .00213     .52901       -0.28492  -3.11169

Average wins by position in AL west:  89.1 83.4 78.3 70.4 89.2
AL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Angels            42   34   .517   86.4   75.6   55.25467    1.02191   56.27657       -2.32113   1.22424
Rangers           42   35   .500   82.7   79.3   27.35260     .97001   28.32261        3.66953  -1.35797
Mariners          39   38   .499   80.8   81.2   16.33538     .76478   17.10017       -2.06399  -0.50951
Athletics         33   44   .468   71.3   90.7    1.05735     .01663    1.07398         .27602  -1.07578

Average wins by AL Wild Card:  93.3

Average wins by position in NL East:  88.5 83.9 80.2 75.6 61.4 88.6
NL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Marlins           41   39   .480   81.5   80.5   20.81531    2.95397   23.76928        1.32456   7.54341
Phillies          39   36   .484   82.8   79.2   28.28415    4.27897   32.56311       -7.20196  -3.72355
Mets              38   39   .520   83.6   78.4   35.08649    3.09743   38.18392        3.14396 -20.24534
Braves            37   40   .498   80.1   81.9   15.80583    2.27728   18.08311        3.84490   6.73172
Nationals         22   54   .450   61.6  100.4     .00823     .00049     .00872       -0.00330  -0.01878

Average wins by position in NL Central:  89.7 85.2 82.0 79.2 76.1 71.8 89.7
NL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Brewers           42   36   .483   83.9   78.1   27.58620    5.59749   33.18369       -4.30551   5.25552
Cardinals         42   38   .520   86.0   76.0   42.51559    6.06752   48.58311        3.51232 -13.36918
Reds              38   38   .463   78.9   83.1    7.70193    2.58257   10.28450        1.75472   4.72477
Cubs              37   38   .485   80.9   81.1   13.23889    3.86406   17.10295        3.65930  -6.24001
Astros            37   39   .456   77.1   84.9    4.57002    1.34862    5.91864         .38371   3.02726
Pirates           36   42   .474   77.3   84.7    4.38738    1.48207    5.86946       -2.43075  -0.03144

Average wins by position in NL West:  98.5 88.6 82.0 74.1 67.8 98.6
NL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs      1D Change 7D Change
Dodgers           50   29   .562   98.1   63.9   88.63127    8.37308   97.00434         .57554  -0.89494
Giants            42   35   .473   83.3   78.7    3.23764   18.46822   21.70586       -2.40860   4.45982
Rockies           41   37   .522   86.9   75.1    8.07968   38.92431   47.00400       -1.62563  13.94329
Padres            34   43   .438   71.7   90.3     .02889     .40648     .43537       -0.10909  -0.34208
Diamondbacks      31   47   .473   71.1   90.9     .02252     .27745     .29996       -0.11414  -0.82046

Average wins by NL Wild Card:  89.7

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.

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