ValleyCats Playoff Odds
Update as of Sunday afternoon: Each team split its last two games, and the playoff results predictably changed little. I have the ValleyCats at 36.13%, Vermont at 51.40% and Connecticut at 12.46%.
I put together a quick-and-dirty simulation for the rest of the season in an attempt to answer that question. I’ll try not to go into too many details about how I made the simulation, because I don’t expect that many of you care; leave a comment or email me if you want to know more. But a quick and fairly technical summary: I first figured each team’s pythagorean record, which estimates a team’s performance going forward from its current run differential. Then I plugged those records into Bill James’s log5 formula to figure the odds that each team wins each game. I then used these odds to simulate the Tri-City, Vermont and Connecticut games for the rest of the season*, and played out the season 1,000,000 times. (This task is made a lot easier by the fact that the wild card will almost certainly not come out of the Stedler Division, so I only had to worry about three teams.)
*I included makeups for games that have been lost to rain this year – Tri-City vs Jamestown, Vermont vs Batavia and Staten Island – because they will be played if they affect the pennant race at the season’s end. (My mistake – these games will not be made up.)
Here were the results:
|TRI + VER tie:||9.5976|
|TRI + CT tie:||2.2061|
|CT + VER tie:||2.9302|
That comes out to a 16% chance that we’ll end up in some sort of tie. The same log5 process I used above can create odds that each team wins
a head-to-head play-in game (there is no play-in game; the tiebreaker is divisional record), allowing us to estimate the full odds that each team makes the playoffs (for simplicity’s sake, I assumed that each team would win the three-way tie one-third of the time):
I was surprised that Connecticut’s odds are so low. But if you look at run differential, the Tigers just haven’t been very good this season. They rank dead last in runs scored and have a worse run differential than all but two teams; their Pythagorean record pegs Connecticut as a .426 team, rather than a .500 one. The Tigers are 10-5 in one-run games, and will probably not be as lucky going forward.
The ValleyCats have a better run differential and expected record than Vermont, but the 1.5-game edge in the standings is enough for Vermont to remain the favorite. Still, I can assure you that their playoff odds are as high as they’ve been all season.
Two major caveats come with these results. The first is that my simulation does not currently discriminate between home and road games, treating them all equally. I will probably build in an adjustment for this in the next edition of my playoff odds. The second is less clear-cut. Right now, all of my predictions are based on full-season data, so games in June count just as much as games in August. I am not sure if this is optimal or not, particularly in a league where players get promoted relatively frequently; when I do this again, I’ll consider weighting recent results more heavily. It clearly makes a difference in this race – Vermont is playing terribly of late, while the ValleyCats are hot. If you think recent results are more predictive than early-season games, you should consider Tri-City somewhat more likely to make the playoffs than these numbers, and the opposite for Vermont.