The puzzle that is the Astros’ rotation

The Astros willl need to use 3 - 4 rounds of the pitching rotation before the end of the season. And, given the playoff race, they all are important games. Assuming the Astros make the playoffs, there is also a question as to who will be the starters in those games. But some confounding issues make the starting pitcher puzzle harder than it has been in recent years.

After the magnificent pitching performances of the 2022 season, the Astros didn’t expect this kind of puzzle. But a combination of factors—injuries, reliance upon rookies, and regression—have made the rotation a question mark in these final games.

ROOKIE PITCHERS

The Astros currently have two rookies in their rotation—Hunter Brown and J.P. France. Normally teams will place limits on rookie pitchers’ innings workload. The reason is that rookie pitchers are facing higher workloads than they have ever faced, and many of those innings are more stressful than their experience in the minor leagues. The current thinking by many teams is that pitchers’ seasonal workload should be increased gradually from year to year in order to avoid the onset of fatigue and related performance decline. I haven’t read any indications of the Astros’ current view regarding season limits on starters, but over the previous 5 or so years, the Astros’ pitching coaches stated that they were aware of the need to avoid significant increases in innings pitched from year to year.

So far this season, Brown has already pitched 15 more innings than 2022 (both minors and majors), which is a 12% increase. Brown has already faced 96 more batters in 2023, which is 20% increase in total batters faced in 2022. Between minors and the majors, J.P. France has already pitched 145 innings, which is 35 innings more than 2022—a 32% increase. France has faced 136 more batters than 2022, which is a 28% increase. And with Brown and France each likely to pitch 3 or 4 more starts, these measures of increased workload will only go up.

We can also look at how Brown’s and France’s workload stack up against the other rookie starting pitchers in the major leagues. Hunter Brown has the second highest MLB workload, measured by either innings or total batters, of any rookie starter. J.P. France has the fifth highest MLB workload among rookie starting pitchers. The rookie stater with the No. 1 workload is arguably unlike the other rookie starters. Kodai Senga is a 30 year Japanese veteran pitcher, and likely has more professional pitching experience than most MLB rookies. If Senga is not included on the list, Brown would have the highest MLB workload among rookie starters.

Both Brown and France have suffered a recent decline in performance. It’s unclear if this is just regression or symptomatic of seasonal fatigue. The table below shows some of the concerning declines in performance since Aug. 22 compared to the seasonal performance.

ERA, FIP, HR/9, BB/9 (“Since Aug. 22” in parentheses)

Hunter Brown ERA 4.84 (7.35), FIP 4.00 (4.16), HR/9 1.29 (1.35), BB /9 3.10 (5.40)

J.P. France ERA 3.77 (8.53), FIP 4.77 (8.10), HR/9 1.38 (3.32), BB /9 2.84 (5.21)

The three-week time period since Aug. 22 is a small sample size, but it provides an indication of the trajectory of declining performance. Both Brown and France have experienced increases in ERA, FIP, HR/9, and walk rate. As I noted last week, France is projected to face 25% regression in ERA over the remainder of the season, and the rising peripherals (particular HR and walk rates) may be a warning sign.

My conclusion is that the Astros should no longer push Brown or France to pitch 6 or 7 innings. Indeed, Brown hasn’t threatened the 6 inning mark recently due to poor performance and high pitch counts. Ideally, the Astros should consider using Brown and France in an opener type role, whereby they are planned as a 3 or 4 inning starter. Perhaps Urquidy and another long reliever could be planned as the “middle starter” for their games. This would reduce the accumulation of workload on Brown and France, which would increase their availability in the post season. In addition, this strategy would reduce the liklihood of either pitcher giving up a big inning as they deal with fatigue.

STARTERS’ PERFORMANCE ISSUES

In the period since Aug. 22, Justin Verlander and Framber Valdez are the only starters to post a good ERA—-2.63 for Verlander and 2.00 for Valdez. All of the other starters have a poor ERA over that span: Cristian Javier, 7.07; Brown, 7.35; France, 8.53; and Urquidy, 7.71. This is particularly concerning in the case of Javier, who is the No. 3 starter and likely a starter in the post-season.

The good news is that Javier’s and Verlander’s stuff has not suffered during that recent period. Javier exhibited an increase in Stuff+ for the period, from 101 for the season to 107 since Aug. 22. Verlander’s season Stuff+ of 107 remained the same during the period since Aug. 22. Urquidy’s Stuff+ also improved during this period, increasing from 102 for the season to 105 for the recent sample.

The Stuff+ for Hunter Brown and J.P. France declined abruptly for the recent period, which may lend credence to the fatigue issue discussed previously. Brown and France posted a 105 and 103 Stuff+ for the season, but the period since Aug. 22 showed a Stuff+ decline to 94 and 99, respectively.

Given his recent decline in ERA and difficulty pitching deeply into games, should Javier be utilized in a manner similar to my suggestion for Brown and France? Ideally, perhaps Javier would pitch as a tandem starter or as a long reliever in the bullpen. However, the reality of available starting pitchers could prevent an ideal solution.

But, in any event, it’s possible that Javier may continue to struggle as he has in recent games, and could require long relief back up. Currently, Urquidy is the only pitcher with starting experience in the bullpen. Joel Kuhnel was the Sept. 1 call up, but he has no starting experience. Presumably, the Astros could move “long relievers” back and forth between AAA and the major league club. Brian Bielak, Shawn Dubin, Seth Martinez, and Ronel Blanco are potential long relievers in that role. However Blanco’s availability may be limited, given the number of times he has been optioned this season.

The Astros’ strategy for the rotation may require some creative efforts by the front office.