If only it were this easy

My daily, baseball must-read this time of year is the postseason odds report on Baseball Prospectus. What the stat heads at BP do is simulate the remainder of the season one million times to come up with the most-accurate projected order of finish.

If only it were that easy.

Nevertheless, as of right now the winner of the National League’s wild card will need 85 victories. So who gets it? Not the Phillies. They finish with 84 wins and have a 36 percent chance to win the wild card.

Here’s how the BP simulation solves the National League:

Average wins by position in NL East:  99.0 83.8 79.8 77.8 70.8
NL East           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs
Mets              92   58   .552   99.0   63.0  100.00000     .00000  100.00000
Phillies          78   73   .491   83.7   78.3     .00000   36.60086   36.60086
Marlins           74   77   .485   79.4   82.6     .00000     .81411     .81411
Braves            73   78   .480   78.3   83.7     .00000     .05052     .05052
Nationals         66   85   .450   70.8   91.2     .00000     .00000     .00000
Average wins by position in NL Central:  86.5 80.0 77.8 73.2 68.9 66.4
NL Central        W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs
Cardinals         80   69   .478   86.5   75.5   99.66073     .01979   99.68052
Reds              74   77   .468   79.6   82.4     .21103     .43616     .64719
Astros            72   78   .490   78.2   83.8     .12823     .07525     .20348
Brewers           68   83   .452   73.2   88.8     .00000     .00000     .00000
Pirates           64   87   .417   68.6   93.4     .00000     .00000     .00000
Cubs              62   90   .443   66.7   95.3     .00000     .00000     .00000
Average wins by position in NL West:  86.3 84.4 80.2 77.4 75.6
NL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs
Padres            79   71   .525   85.6   76.4   59.25494   25.28678   84.54172
Dodgers           79   72   .530   85.0   77.0   40.30682   35.29052   75.59734
Giants            74   76   .490   80.1   81.9     .42963    1.41416    1.84378
Diamondbacks      71   79   .483   76.4   85.6     .00827     .00922     .01749
Rockies           71   80   .497   76.8   85.2     .00033     .00264     .00298

Average wins by NL Wild Card:  84.9



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.