It's Not Devil Magic. The Astros Are Actually a Good Team

Some may say the Astros winning stretch is a matter of good luck. But the numbers show this team is as good as it record, thanks to an outstanding bullpen.

That was a pleasant weekend. The Astros won a blowout game on Friday night and then a pair of walk off wins to sweep the Twins. That was the Astros 5th straight win, their longest win streak of the season.

The Astros have now won 8 of their last 10 games, 15 of their last 20, 20 of their last 30, and 24 of their last 36 games. Before this winning stretch happened, the Astros were under .500 at 17-18 after a May 6 loss to the Brewers. They were also 4 games back in the AL West and in 4th place. Since then, they have gained 8.5 games on the division. They lead the AL West by 4 1/2 games over the Mariners (and 5 1/2 games over the Rangers) and are only a game behind the Yankees for the 2nd best record in the AL.

It has been a delightful stretch.

And yet, I find a clear sense among Astros fans that the team’s record is fool’s gold. That it, it is not real, and is based on “luck,” “fortune,” or as one comment in my socials said “devil magic.”

And even if it isn’t “luck,” the sense is that the Astros shouldn’t be this good. That sentiment was expressed by Chandler Rome today in The Athletic, where he wrote “anyone inside the Houston Astros’ infrastructure is kidding if they claim to have predicted this. A team crippled by injuries and held together by castoffs continues to win, ascending to a place it always seems to be.”

Rome’s sentiment seems to be shared by lots of Astros fans. And I think it is overstated.

This team is succeeding on talent, primarily in its bullpen, and has a record that is right about where it should be.

Lucky? Not Really

One reason that discussions of the Astros luck have spiked in recent days is that the Astros have won a pair of one-run games. And victories in one-run games tend to be a product of luck.

One can see that in the Astros wins this weekend over the Twins this weekend. On Saturday, they won on a Cam Smith grounder that happened to find a hole in the infield rather than in the glove of a Twin. On Sunday, they scored a tying run in the 9th thanks to Jose Altuve hitting a grounder soft enough that even the strong-armed Carlos Correa could not throw him out at first base. That advanced Jeremy Pena to 3rd base with one out and he scored one batter later on a Victor Caratini fly ball.

That is a couple of clear examples of luck for the Astros. Sure, the pitching was excellent for the Astros over the weekend, but they scored key runs thanks to good bits of fortune.

Overall, the Astros are 13-7 in one-run games. One run games are essentially coin flips, decided on things like grounders being hit to the right spot. The Astros good record in one-runs games is indeed a sign of good fortune.

Good teams may “know how to win” as yesterday’s hero Mauricio Dubon said. And that is by winning a bunch of blowout games. And the Astros are doing that; they are 10-5. That’s a higher winning percentage than in one-run games, and another sign of a very good team.

Put together, the Astros are right about where they should be in their record. How can one tell that? One measure is the pythagorean or expected record, which is based on the number of runs the team has scored and allowed. The Astros expected record is 40-31, only one game behind their actual record. It means they are lucky, but only a tiny bit lucky.

Another measure that accounts for luck is what is called 3rd order wins. It looks at how many wins a team should have scored and allowed, factoring out factors such as sequencing luck and opponent quality. Again, the Astros are ahead of where they should be, but not by much.

The Astros have won 1.7 more games than they should have by this measure. That’s obviously not a lot. In fact, there are 18 teams whose real record is further away from their 3rd order record than the Astros.

In short, the Astros record is a little bit better than it should be, but only a little bit.

Expected Stats Show No Effect of Luck

Of course, a team’s record is not the only way to measure luck in baseball. Thanks to Statcast, we can now look in a very granular way at whether or not teams (and individual players) are hitting or pitching in good luck.

Are the Astros hitting in good or back luck? According to the expected statistics at Baseball Savant, Astros hitters have an actual batting average of .253, but an expected batting average of. 257. They have an actual slugging percentage of .391, but an expected slugging percentage of .418. Their weighted on base average (wOBA) is .313, but their expected wOBA (xwOBA) is .324.

That presumes they are hitting in bad luck. Except the whole league is. Due to increased drag on the ball this season, the average MLB team is hitting 8 points below their expected batting average, 27 points below their expected slugging percentage, and 12 points below their xwOBA. The Astros are hitting in neither good nor bad luck. They are about where they are supposed to be.

It’s similar for Astros pitchers. They are allowing an wOBA of .290. They are allowing an xwOBA of .302. There is a 12 point different there, right at league average.

But one thing that is not at league average—the Astros wOBA and xwOBA. The Astros .290 wOBA is the second best in the baseball. The xwOBA is best in the majors. They have the lowest batting average allowed and expected batting average allowed. In addition, they have the sixth lowest slugging percentage allowed and second lowest expected slugging percentage allowed. In short, the pitching is among the best in baseball.

And that has been led by the bullpen. Joe Sheehan wrote yesterday in his newsletter that “Astros relief pitchers are sixth in ERA, first in FIP, and second in FanGraphs’ WAR -- the latter while carrying the sixth-lightest load in baseball. They’ve struck out a league-leading 28.2% of batters faced, and they’re first with an 18.8% K-BB%. The Astros have lost just three games when leading after six innings, just two when leading after seven.”

Bennett Sousa recorded 5 outs facing 4 batters yesterday. He’s part of the outstanding 2025 Astros bullpen.

Premier Pitching

Are the Astros lucky? Not really. Rome wrote today that “Fortune is involved, yes, but premier pitching is propelling it.” The Astros have gone 24-12 since May 7. In that stretch, they have allowed 3.47 runs per game, which would be good for 3rd best in the majors over the entire season.

Yes, they were lucky to get Cam Smith and Jose Altuve’s ground ball base hits this weekend to win one-run games over the Twins. But they also won those games because they allowed only 2 runs on Saturday and 1 run on Sunday. They were lucky to get those base hits, but their pitching put them in a position to benefit from that good fortune. And that’s how they been winning all season—their pitching is keeping opponents off the board so their offense can score enough to win.