Updated World Series Odds Tell a New Story: Both Championship Series Are Now Up for Grabs
Just a few days ago, we were talking about the World Series collision course that the Philadelphia Phillies and Texas Rangers seemed to be on. But that was then. This is now. Both the Houston Astros and the Arizona Diamondbacks won on Thursday, the first time in the entire 2023 MLB postseason that multiple teams who were trailing in a series won on the same day. Trailing teams went 3-0 on Wednesday and Thursday combined; they’d been 2-12 in the playoffs before then.
Naturally, this has had a big effect on the World Series odds, with the Astros and D-backs both adding at least 10 percentage points to their chances of making the Fall Classic. In fact, with the ALCS tied 2-2, Houston is now favored again (55%) to get to a third consecutive World Series, and they’ve more than doubled their championship odds in the past few days:
For Arizona, rookie starter Brandon Pfaadt delivered in what felt like a must-win game, validating the faith the team has placed in him despite his lack of experience. Striking out nine Phillies and allowing just two hits and no runs in 5 ⅔ innings, Pfaadt did what his more well-regarded rotation-mates (Zac Gallen and Merrill Kelly) could not earlier in the NLCS: Cool off a Philadelphia offense that was averaging nearly six runs per game in the postseason before Game 3. Finally scratching out some runs late against the Phillies’ previously unhittable bullpen, Arizona took advantage of the series shifting back home to Chase Field, where they’re 2-0 in the postseason and 45-38 on the season overall.
The big question for the Diamondbacks now: Can they hold serve at home in a Game 4 as both teams reach deep into their bags of pitchers, then somehow find a way to win on the road against Philly, who has been unbeatable at Citizens Bank Park this postseason?
The Astros have the opposite problem in their comeback quest. Houston has handled the road just fine, not only in the playoffs (when they’re 4-0 away from Minute Maid Park) but also during the season overall, going an MLB-best 55-30 on the road, including the postseason. But the Astros have one of the most puzzling splits in baseball right now, with a home record (40-45, including the postseason) that is significantly worse than their road mark.
Obviously, teams usually win more at home than on the road; in 2023, home teams are 1,279-1,180 in total (a 52% winning percentage) despite a losing record (13-16) in the postseason. So how bizarre is Houston’s departure from the norm? As we can see in the chart below, no team’s road record has outperformed what we would expect based on their home record more than the Astros — and only the long-suffering Colorado Rockies are even in the same neighborhood in terms of home-road split outliers overall.
Making things even stranger, the Astros actually had MLB’s second-best road record (56-31) last season, including the playoffs, and they had the ninth-best road record (48-41) in 2021. It’s hard to say what has changed since then — particularly because Houston had the lowest rate of roster turnover during the 2023 regular season, in terms of the share of team playing time given to players who weren’t on the 2022 team. Sometimes, we just have to shrug and say that splits happen.
But how real Houston’s home troubles are does have a substantial effect on the rest of this season. If the Astros can win at least one of their two remaining home contests — the Rangers and Astros are in Arlington on Friday for Game 5 before going back to Houston for Games 6 and (if necessary) 7 — they will probably win this series. If not, and depending on what the Phillies and Diamondbacks do in their own battles, the World Series odds could be due for another huge shift by next week.
