Astros’ Offense Slumps—Particularly Compared to Last Year
It’s no secret that the Astros’ offense has struggled this month. Injuries have been part of the problem: Jose Altuve, Michael Brantley, and Chas McCormick have been out of the lineup. The timeline for the return of Altuve and Brantley is not specific. But beyond the injuries, some of the Astros’ batters are slumping. Notably, the Astros need Alex Bregman and Jose Abreu to improve their offense.
Hopefully, the Astros’ offensive outburst in game 2 of the Cubs’ series foreshadows an end to the slump. Only time will tell.
Astros Offense Ranking
The offense’s current ranking among the 30 MLB teams is ugly. (Source: Fangraphs Leaderboard)
(Current OPS, Current Rank / 2022 OPS, 2022 Rank / Ranking Decrease)
OPS Ranking: .680, 28th / .743, 7th / -20
Needless to say, it’s not good when only two teams (Detroit and Cleveland) have suffered a worse OPS. And, by the way, the ranking is exactly the same for the alternative offense measurement wRC+. The Astros team ranking has dropped like a rock since 2022. It’s unlikely that the injuries can account for the full extent of this decline. And maybe, just maybe, that’s a reason to expect an improvement in the Astros’ OPS in the future.
Two additional components of the Astros’ offense ranking explain some things that have gone wrong.
(Current ISO, Current Rank / 2022 ISO, 2022 Rank / Ranking Decrease)
Isolated Power Ranking: .129, 27th / .176, 4th / -23
(Current HRs, Current Rank / 2022 HRs, 2022 Rank / Ranking Decrease)
Home Run Ranking: 36, 26th / 214, 4th / -22
(Current BB%, Current Rank / 2022 BB%, 2022 Rank / Ranking Decrease)
Walk Percent Ranking: 8.0%, 23rd / 8.7%, 8th / – 15
- I have focused on the power measures, ISO, and HRs, because both measures are among the most important determinants of offensive production. Typically home runs and power are important qualifiers for entering the playoffs. (The Cleveland Guardians were an exception that proved the rule last year.) The Astros were a top-five team in both ISO and HRs last year. I believe the Astros’ severe drop-off in power ranking is the most significant current weakness. This has to change if the Astros want to have an above-average offense at season’s end.
- I have also focused on walk rate because it is an obvious determinant of getting guys on base and reflects the team’s general approach at the plate. The Astros’ ranking is not as low as the HR/ISO ranking. But the walk rate is still significantly worse than last year. A diminished walk rate can signal that the batters’ approach is breaking down. And problems with approach frequently accompany a batting slump. Sometimes the pressure of a batting slump will cause the batter to lose patience or swing at the wrong pitches.
- Baseball Savant’s plate discipline measures may shed light on batting approach issues that need improvement. The “first pitch swing” stat usually is a good measure of patience, with a lower percentage indicating more patience. The Astros’ first-pitch swing percentage (33%) is substantially above league average (30%). Dubon, Tucker, Pena, and Diaz appear to be swing-happy on the first pitch, with first-pitch swing percentages over 40%. The Astros batters are also higher than the league average on Chase % and Zone Swing %. The negative consequences of chasing pitches is fairly obvious. An excessive zone swing percentage may hinder the batter’s selectivity in swinging rather than swinging at pitches to do damage. Dubon and Tucker may fall in this category, with zone swing percentages above 70%.
Situational Win Probability Stats
Fangraphs’ win probability statistics provide a context-dependent view of the offense. I particularly like the Run Expectancy stats (RE24 and REW), which measure how much a batter improves or decreases the run expectancy in each plate appearance. Run expectancy is based on the 24 Base-Out stats (combinations of runners on base and number of outs), and a positive/negative value means that the outcome was above or below league average for that situation. The run expectancy stats are unique in that they consider the consequences of double plays, moving runners over, and other productive outs, as well as hits and walks. In this sense, the RE24 stat indicates how well a team executes its offense.
The good news is that RE24 and REW are positive, meaning that the Astros have executed their offense in various situations better than league average. But the Astros currently are falling behind the pace of 2022. In 2022, REW indicated that the Astros gained 6.9 wins from the ability to execute situationally. Currently, the Astros’ REW attains only 0.55 wins above average. The Astros have only five batters who are positive (above average) in RE24 as shown below, with the remainder below average.
RE 24 Contributions (runs above average)
Alvarez 22.89
McCormick 7.8
Tucker 4.96
Bregman 4.47
Pena 2.35
If it sometimes feels like Yordan Alvarez is carrying the Astros’ offense on his back, the RE24 stat seems to support that conclusion. Despite the fact that Chas McCormick was out of the lineup with an injury for a couple of weeks, he is one of the best contributors to offensive run expectancy numbers. McCormick’s return to the lineup this week should provide a boost to the offense. The Astros offense probably needs more than five batters with positive RE24 contributions to operate consistently. In 2022 the Astros’ offense had eight batters with positive RE24 contributions.
Wrap Up
I think it’s likely that the offense will improve in the future. Whether it will improve enough is an unknown question. The X- stats (expected batting stats at Baseball Savant) indicates that the Astros’ offense has been somewhat unlucky. They have been unluckiest for wOBA on contact, with a xwOBACON 21 points higher than actual wOBACON. Batters with significantly worse luck on contact include: Tucker, Bregman, McCormick, Abreu, and Hensley. If the offense continues to struggle at mid-year, particularly in terms of power numbers, I wouldn’t be surprised if the Astros are active in the trade market, seeking a power bat to add to the offense.