3 Takeaways: World Series Win Percentage

This week we take a look at World Series Win Percentage and which teams are favored by the projections. First a small explainer of what World Series Win Percentage is and how it works.

World Series Win Percentage is based off of a team’s adjusted playoff percentage (the odds of a team reaching the divisional series round) and their expected winning percentage as a whole. Expected win percentage is based off of underlying stats that indicate the strength of the team exclusive of schedule.

What it boils down to is estimating team quality from who’s on the roster and how they’ve performed so far, and then using those estimates to simulate possible playoff matchups, and finally counting how frequently each team wins the World Series in those simulations.

Toronto Blue Jays – 19.4%

Not many gripes to be had here. While the Jays are slowly sliding back to the pack, holding a 2.5-game lead on the Yankees at present, there is little doubt that they’re one of the favorites in October thanks to a dynamic lineup and the presence of David Price and Marcus Stroman atop their rotation. All the numbers like them too – they have a run differential of +213, good for best in the majors, and 100 runs better than the next closest team (St. Louis). The Jays own the league’s highest third-order win percentage (by a hair), and second-highest expected win percentage per Baseball Prospectus. These are major drivers of the World Series Win Percentage, and it’s no surprise that projections match up well with common wisdom when it comes to the Jays.

Los Angeles Dodgers – 18.9%

The Dodgers third-order win percentage is a shade behind the Blue Jays (.614 to .615) and they hold the top spot in expected win percentage as well (.587). They haven’t had the most convincing season, especially among contenders (they’re behind all three NL Central teams on record alone), but the projections are going to value the long track records produced by most of the Dodgers high-end performers – and might well undervalue the shorter track records of high-impact talents on teams like the Cubs, in terms of understanding the changes made to Jake Arrieta, or correctly predicting Kris Bryant, Kyle Schwarber, Addison Russell and others. Still, this isn’t going to raise too many eyebrows given two of the best pitchers in baseball wear Dodgers blue and the lineup is good enough to make it work, especially with prospect phenom Corey Seager providing a spark. Getting Yasiel Puig back in time for the playoffs would be a huge boost too.

Houston Astros – 10.1%

This is a bit of a departure from conventional wisdom. Houston ranks fourth in the category despite (currently) being consigned to the Wild Card game, which is a highly variable proposition to say the least. Still, Houston is third in the majors in third-order win percentage, and fourth in expected win percentage (per BP, as always) on the strength of their +92 run differential. That combined with PECOTA projections form the basis for the simulations that run, and spit out these numbers. Houston’s underlying stats give them a really good chance if they can get to a divisional series, but of course, underlying states don’t mean a ton in a one-game series.

For the full Playoff Odds Power Rankings, click here.