Three quick items related to the Astros:

Jason Alexander has turned into a surprising addition to the Astros’ rotation. He pitched an exceptional game against the Yankees, taking a no hitter through the 5th inning and a shutout through the sixth inning. Perhaps the most striking comparison is Alexander’s statistical turnaround from the Oakland A’s earlier this year to his current spot with the Astros.

Alexander pitched out of the bullpen with the A’s, but has primarily pitched as a starter with the Astros. His basic stats are much better with the Astros:

Oakland 2025 18.0 / 10.44 / 5.66

Astros 2025 3.16 / 3.77 / 4.19

Perhaps the biggest difference between his Oakland stint and his performance with the Astros has been the ability to generate ground balls and avoid hard contact.

(GB %, GB-Fly ratio, EV, Hard Hit %)

Oakland 2025 36% / 0.82 / 95.3 mph / 64%

Astros 2025 55% / 2.10 / 86.8 mph / 44%

In terms of pitch selection, the most significant difference is that Alexander is throwing his change up more now (25% with Oakland and 34% with Houston). The pitch models indicate that Alexander’s stuff has improved with the Astros. His Pitchbot ERA is 3.75 with the Astros and 4.97 with the A’s.

The Astros have the reputation for resurrecting pitching projects. And Jason Alexander has turned into example no. 10,382.

2. Astros and Ground Balls

Ground ball rates in baseball continue a recent downward trend. Fangraphs points out that the league wide groundball rate has dropped from 47% to 42.3% since 2015. Both hitters and pitchers contribute to this trend. Hitters try to put the ball in the air, because that’s how the offense causes damage. And pitchers increasingly chase higher whiff rates which often means aiming the fastball for the top of the strike zone.

This leads me to look at how the Astros rank in hitting and inducing ground balls. The Astros’ batters are pretty close to average (42.2% ranked 13th) at hitting the ball into the ground. The slightly above average GB rate probably contributes to the team’s 2d ranked batting average (.253). Ground balls tend to produce a higher batting average than fly balls. But the downside is that the team’s isolated power (ISO) is slightly below average (16th). Ground balls don’t produce a lot of extra bases. If the team wants more slugging, it probably will need to curb the ground ball tendency.

Turning to the pitching side, the Astros’ ground ball tendencies are more interesting As an overall pitching staff, the Astros are below average in ground ball rate (ranked 23d at 40.3%). But break it down between starting pitchers and relief pitchers and the results are quite different. The Astros’ starters have the 4th highest GB rate (44.9%). But Astros’ relievers have the lowest GB rate in the majors (32.3%). I don’t think it’s coincidental that the Astros’ relievers have the highest strike out rate in the majors (10.36 K/9). The Astros’ bullpen demonstrates a feature noted in the FG article. When pitchers pursue higher whiff rates, the ground ball rate tends to decline.

It’s pretty clear that the Astros want pitchers with high K-rates in the bullpen. And that success results in fewer ground balls when the relievers enter the game. But ground balls can also be an effective tactic for suppressing run scoring. If a team prioritizes starter length—pitching deeper into games—ground ball pitching can be a welcome attribute. The Astros’ top 2 starters, Framber Valdez and Hunter Brown, are well known for their ground ball inducing ways. Furthermore, as rotation injuries mounted, the Astros added replacement starters (Gordon, Walter, Alexander) who have above average ground ball rates.

However, as the injured starters begin returning, the rotation’s ground ball tendency may decline a bit. The top four ground ball rates in the rotation are Valdez (60%), Alexander (54%), Brown (45%), and Walter (45%). Gordon’s current below average GB rate likely indicates that he currently isn’t pitching at his best. Cristian Javier, who is expected to make his first start this evening, normally has one of the lower GB% among starting pitchers. The same is true for Luis Garcia, who is likely to be added to the rotation in a week or two. Arrighetti hasn’t really established his tendency as either GB or FB, but when he is at his best, his breaking pitches produce ground balls. That is one reason we will be watching how deeply the returning starters can pitch into games. A good ground ball game can allow a starter to throw fewer pitches and pitch with more length.

3. Has the Astros’ offense under performed?

Ben Clemens at Fangraphs wrote a recent piece ranking offenses’ under or over performance. Basically he compares teams’ current wOBA performance to the FG pre-season projection. But he constructed a comparison which intentionally doesn’t penalize teams with a lot of injuries. Some teams like the Tigers and Blue Jays definitely have over performed on offense. But the Astros join the Brewers and Marlins in neither over or under performing their offensive projections.

Now, let me clarify this view of the Astros and Brewers. Both teams nominally are slightly under performing (-.00002) but in the league context, this is not under performance. The overall offensive environment is down, with the league’s teams averaging -0.07 wOBA under performance. Given the league context, the team projections have been accurate for the Astros and Brewers, particularly when injury effects are considered.

Ben Clemens discusses why under or over performance is more difficult than it seems to explain:

Fans of the Dodgers, Astros, and Yankees might be confused by their squad’s placement here.[Astros ranked 10th in over performance] Aren’t all three big disappointments relative to expectations? But two things are true. One, “expectations” aren’t quite the same as projections; the Yankees were projected to have the fourth-highest team wOBA, and instead they have the highest. More importantly in all three cases, though, those teams have had key contributors miss time with injury, and my methodology doesn’t penalize those teams for the missed time. I’m trying to answer which teams have had worse-than-expected performances rather than which teams have been less healthy than expected, so I think that this is a feature and not a bug.

Any thoughts on today 3 Things?