On paper, this year’s World Series between the Houston Astros and Philadelphia Phillies looks like a gigantic mismatch. The Astros won 106 games during the regular season, with a plus-219 run differential, 57.7 wins above replacement¹ and a 1589 Elo rating; the Phillies won 87 with a plus-62 differential, 42.0 WAR and a 1547 Elo. Based on a composite of the differences in those four categories, this is the seventh-most lopsided World Series matchup (on paper) since 1903:

That helps explain why the Astros also have a sizable 67 percent championship probability going into the series, according to our MLB forecast model. Since we started making predictions back in 2015, only one World Series — 2020, when the L.A. Dodgers were 69 percent favorites over the Tampa Bay Rays — saw the favorite carry better odds heading into Game 1 than Houston has right now:

Historically, massive favorites according to the composite method tend to win far more often than not. Nine of the 10 most lopsided World Series went to the favored team — granting that the only exception was No. 1 on the list, when the White Sox bested the uptown rival Cubs in 1906 — and so did 14 of the top 20. More recently, however, things have been a little less predictable. In the FiveThirtyEight Elo era, favorites are 4-3 (even though teams with 60-plus percent chances are 2-0).

So the Phillies face a big gap in credentials on paper. But they are not hopeless. After all, Philadelphia already pulled off one of the biggest upsets in division series history when it knocked off the 101-win Atlanta Braves — a team with an even larger pre-series Elo edge over Philly (48.7 points) than the Astros currently have (42.9).² And the Phillies’ hopes come down to a few areas where they may genuinely have an advantage against the business-like buzzsaw that is Houston.

The first of those is on offense. While the Astros boast dangerous slugger Yordan Álvarez — plus a lineup deep enough to average a very respectable 4.5 runs per game in the ALCS even as the New York Yankees held Álvarez to a downright mortal .675 OPS — the Phillies’ lineup has been on another level this postseason. They lead all playoff teams in runs scored (57), runs per game (5.18, more than a half-run better than any other team), slugging percentage (.442) and are second only to the Toronto Blue Jays — who played just two games before getting eliminated — in OPS (.749). Among hitters with at least 25 plate appearances, nobody in MLB has a better OPS than Bryce Harper’s 1.351 mark; in fact, that’s the 18th-best mark for any qualified hitter in a single postseason ever.

And the scary thing is that, even if Harper regresses some, a number of Philadelphia hitters have room to improve on their postseason numbers to date: Eight of their 10 most-used hitters in the playoffs have a lower OPS this postseason than during the regular season (with Harper and Kyle Schwarber being the only exceptions). If the Phillies can continue their scoring barrage, they will never be outside of striking distance in a game — just ask the San Diego Padres, who could not put the lid on Philly’s offense long enough to hold multiple leads during the late stages of the NLCS.

The other major area where Philadelphia may have an edge on Houston is in the starting rotation. Yes, Houston did get the most WAR from starting pitchers of any team during the regular season, with Philly sitting at No. 3 behind the Astros and Dodgers. But in the playoffs, the Phillies’ aces have shown they can stand toe-to-toe with Houston’s top arms. Philadelphia’s starters collectively have a lower postseason WHIP than Houston’s (0.86 versus 1.10), and three of the four likely Philly starters have a lower WHIP than their starting counterpart on the Astros — Aaron Nola (1.10) versus Justin Verlander (1.50) in Game 1; Zack Wheeler (0.51) versus Framber Valdez (0.87) in Game 2; and Noah Syndergaard (0.75) versus Lance McCullers Jr. (1.18) in Game 4.³

Philly will need to lean heavily on the twin pillars of slugging and starting pitching, because Houston looks better in just about every other area. Defensively, it’s not even a contest (and we wouldn’t expect it to be), as the Astros ranked No. 5 in fielding runs above average⁴ during the regular season while the Phillies ranked 28th. And although the much-maligned Philadelphia bullpen has improved from its perennially abominable reputation in previous seasons — or even earlier this season — it has still lagged behind the Astros during both the regular season (Houston was No. 3 in relief WAR; Philly was No. 12) and the postseason.

All of this makes sense: Houston is plainly the better all-around team on paper. Based on game-by-game odds, the Astros even have a 12 percent chance of sweeping the series and going undefeated in the entire postseason, a feat not accomplished since 1976. But that doesn’t mean the Phillies don’t have a chance. After upset World Series losses in 2019 and 2021, the Astros should know by now that every Fall Classic underdog has its day — a truism more accurate now than ever.

Check out our latest MLB predictions.