February 24, 2011
PS Odds, I Love You
Spring is nearly here, in a temporal sense, at least—in many parts of the country it certainly doesn’t feel very spring-like, but dispatches from the Grapefruit and Cactus leagues assure us that yes, spring is on its way.
Spring raises questions that only autumn can answer—who will win, and who will lose, and how it will happen along the way. I leave it to the psychics and the tarot card readers to claim otherwise. But the absence of perfect knowledge doesn’t mean perfect ignorance—we certainly know some things about how the baseball season will play out. Filled with what Tommy Bennett would call the Quantification Urge, we turn to the Playoff Odds Report.
We’ve given the report a facelift, but at the core it’s what you’re expecting. We start off by assigning each team an expected win percentage; right now this is derived from the Depth Charts, but after the season starts we will be incorporating a team’s performance into the expected win percentage, as well.
From there, using the log5 method and a Monte Carlo simulation, we simulate the results of thousands of seasons of play. Due to unbalanced schedules, we come up with win-loss records that diverge a bit from the numbers on the depth charts. We can also look to see how often a given team won its division or the wild card, and from there we compute the playoff odds.
Consulting the odds lets us put the projected standings in perspective; seeing the Red Sox listed above the Yankees, for instance, gives a certain sense of finality to the projected standings. But looking at the odds reminds us that it could very well be the other way around—or another team altogether could seize the division.
And of course events conspire to remind us how fragile these exercises really are. Yesterday the Cardinals received word that Adam Wainwright could very well miss the entire season. It’s incredible to me how just one player can shape a division race. Here are the projected odds, before and after the Wainwright injury news:
Losing a valuable piece like Wainwright before the season even starts turns the NL Central into a tighter race than before, with the Brewers and Reds the greatest beneficiaries. (Even the Astros seem to benefit, although not by enough to reassure most Astros fans, I imagine.)
And yet—the loss of Wainwright is not the death knell that I think some commentators expected. The Cardinals still have the best player in baseball, after all, and the NL Central is nowhere near as top-heavy as the AL East. The Cardinals still have a very good chance of making the playoffs—they’ll just have to fight a bit harder to do it.
And that, as they say, is why they play the games.