A Stop-and-Start Start to the Season
The Astros have featured pretty good pitching, improved defense, and a frustrating offense. I examine the team's performance so far: where they have surprised, improved, and struggled early in 2025.
Perhaps the best way to describe the opening to the 2025 season for the Astros is to not that the team has won a game and then lost the next one for 10 straight games.
Or one could note that pattern that the Astros won their first series of the season against the Mets, the lost the second series. won the third, lost the fourth, and then won the fifth series this weekend against the Angels.
Every time the Astros win, they follow it up with a loss. Every time the Astros win a series, they follow it up by losing a series.
As a result, some might describe the Astros start as inconsistent. But it is oddly consistent so far.
As befits a team that is right around .500, the Astros have scored 60 runs but allowed only 2 less at 58. They have the record of a team right around .500 and deserve a record right around .500.
Above Average Pitching
I’ll start with the good news. The Astros have pitched pretty well this season. They have allowed 3.87 runs per game this season, which is the 10th best rate so far among major league teams.
The outstanding trait of the pitching staff so far has been its ability to strike out opposing hitters. The Astros leae the majors in both strikeout rate (29.8%) and strikeouts per nine innings (10.93).
Opponents are slashing .190/.273/.333 for a .607 OPS. That’s the fourth lowest OPS of any pitching staff in baseball. So far this season, Astros pitchers are turning the average major league hitter into one who should be sent back down to the minors.
Astros pitchers are succeeding through strikeouts and limiting base hits. They are not doing as well a limiting hard contact. Opponents have 0.99 home runs per nine innings off Astros hurlers; that’s the 14th highest rate in the majors.
The Astros other big weakness on the mound is walks. Astros pitchers have walked 9.2% of opposing batters, the 15th highest rate in the majors. They are limiting hits but giving back some of that benefit by walking batters.
Improved Defense
The Astros made moves this offseason to shore up their defense, especially on the infield. Christian Walker is a huge upgrade over Jon Singleton at first base and they moved Jose Altuve to left field because of his declining range on the infield.
The numbers so far indicate that these moves have worked out. Defensive metrics are maddeningly inconsistent from measure to measure, but overall they show the Astros have very good defense this season. They rank 13th in Defensive Runs Saved (+3), 8th in Fielding Runs Above Average (+8), and 1st in Outs Above Average (+9).
The simplest measure of team defense is defensive efficiency, which simply measures the share of balls hit into play1 turned into outs. The Astros have turned 74% of batted balls into outs, which is the 5th best rate in the majors.
The Astros have allowed the 3rd lowest opponent batting average in baseball so far and the team’s defense is making a big contribution to that effort.
A Struggling Offense
If the pitching is doing well and the defense is doing well, why are the Astros stuck in a win-a-game then lose-a-game pattern. Now it’s time to talk about the offense.
The team has scored 4.0 runs per game this season, tied for 18th best among major league teams. The Astros have slashed .219/.309/320 for a .628 OPS. The good news is that the pitching has been good enough that the Astros have a better batting average, on base percentage and OPS than their opponents. The bad news is that those offensive numbers are not very good. The Astros OPS is 23rd best in the majors.
One offensive number that has improved in the early going for the Astros is their walk rate. Astros hitters have walked in 10.5% of their plate appearances this season, which is the 5th highest in baseball so far. It is a marked improvement from 2024, when Astros hitters were 27th in walk rate.
Of course, more patience at the plate has come at a cost. The Astros are striking out in 22.9% of their plate appearances, which is 16th lowest in baseball. In 2024, Astros hitters had the 2nd lowest strikeout rate in baseball, part of their long-standing offensive identity as a low-strikeout, high contact team. Is this changing? We will have to get more data (and for the team to face more pitching staffs) to make an actual conclusion.
The Astros biggest issue on offense is a lack of power. The team’s isoloted slugging percentage is .101,2 the third lowest in the majors. Or to put it another way, the Astros have hit only 12 home runs this season, which is tied for 21st most in the majors.
Small Sample Size
Some of the trends I have identified here fit with what we expected from the Astros (high strikeout rates by the pitchers), some are surprises (the high walk rate by batters), and some reflect the deliberate offseason decision-making (the improved defense).
But none are permanent. The Astros have played less than 10% of their season. They have only played 5 opponents and the numbers may be skewed by the strengths and weaknesses of those particular opponents as compared to the average MLB team. The team should revert to hitting with more power soon, but the concern is that it will come with taking fewer walks.
If you observed these stats over a two-and-a-half week period in mid-July, no one would take much notice of them. They would fade in with the rest of the stats the team had accumulated throughout the season. These stats stand out because the there are no others to compare them to. That will change over time.
Overall, the Astros have not stood out over their first 15 games. They are a game under .500 and that record is pretty close to how they have played. They have not dug a hole in the AL West like they did with their slow start in 2024, but they have not played as one of the better teams in baseball as they did so often in their most recent season.
We will have to wait more to see what kind of team this is. They have not allowed us to draw many conclusions in the first 15 games of 2025.
So you take away strikeouts, walks, hit batter and home runs.
Isolated slugging is measured by subtracting batting average from slugging percentage. It thus isolates how much slugging comes from getting extra base hits.