Once again, the PC on my office desk (possibly with a cat sleeping on it) has started crunching the postseason numbers. Indeed, if you’re a particularly keen observer, you may have noticed that the ZiPS Game-by-Game Postseason Odds are now available for your adoration or scorn. Yes, these are technically probabilities rather than odds, but you don’t get the name the articles, bossypants!

For those of you who are new to the ZiPS playoff projections, or who wisely don’t reserve portions of their brain for remembering Dan Szymborski stuff, the playoff model is much different than the generalized seasonal model you see utilized in the articles I publish over the course of the season. The macro-level projections used to forecast a full 162-game season are less suitable when applied to the postseason, given the more compact nature of a three-, five-, or seven-game series. When you’re looking a week into the future rather than half a year, you’re able to take a more ground-level view of the relative strength of teams. You’re able to make educated guesses as to who is starting each game, what the lineups will look like, who is healthy and who is not, and so on. The ZiPS game matchup tool has a built-in lineup estimator that projects every pitcher’s and batter’s line against every other pitcher and batter, so there is no need to look at a team’s generalized offensive strength. The playoffs also come with the benefit of being able to run the full, more robust model of ZiPS rather than the simpler model used during the regular season, a compromise necessitated by the fact that projecting a majors’ worth of players takes more than a day.

For 2023, I’ve continued to refine my models to try to more accurately project playoff bullpen usage, and have also done some more work on modeling how individual pitchers will fare when being used on short rest.

Is the model perfect? Of course not. All models are wrong, but some are useful. The approach I take has benefits in some very specific situations where a team’s seasonal record isn’t a good predictor of performance. For instance, ZiPS saw the Nationals as being far more dangerous to the Dodgers in 2019 than conventional wisdom did by virtue of the team’s ability to concentrate a very large percentage of their innings in a few excellent pitchers. But there’s still more work to be done. For example, I’d like to be able to more accurately predict bullpen workload consequences on a daily basis rather than a series-to-series one.

These odds will be updated continually as we get closer to first pitch in each round and each game’s starters become clear. If a game’s starters haven’t been officially confirmed, the pitcher listed is my most educated guess. Projections for the Division Series will populate after the Wild Card Series have concluded, with the Championship Series projections coming after the Division Series wraps, and so on. For the moment, you’ll see those tabs grayed out. In addition to game-by-game projections, you’ll also find series odds, which will update as each series progresses.

Since FanGraphs offers a few different projection tools, here’s a quick summary of the features of the three — the FanGraphs Game Odds, the FanGraphs Playoff Odds, and the ZiPS Game-By-Game — that are most relevant for the postseason:

All that’s left now is the fun part: actually playing the games!