Using WPA to Identify Houston’s Best Pitchers of 2023

There was a time when you could tell a lot about a pitcher simply from his win-loss record.

That was back when pitchers regularly completed half of the games they started, and every starter averaged seven or more innings per game. The era of specialty and the practice of protecting those valuable arms has changed the game enough that a pitcher’s win-loss record is now mostly useless.

So what statistic could we use to tell us more? ERA is too dependent on other factors, FIP doesn’t take into account pitching volume, and WHIP is, for the most part, situationally dependent. The leverage index differential is not taken into account by any of these stats.

What I thought could give a clearer picture of which pitchers were real “gamers” in 2023 is which players performed best (or worst) in each game. I went into each “advanced” box score on FanGraphs, and identified the pitcher with the highest WPA in each Astros win, and the pitcher with the lowest WPA in each Astros loss. Then, I awarded wins (and losses) to those players who earned them. Here’s what I found.

The seven players who finished with winning records should surprise nobody. Cristian Javier turned in the best record, at 10-2, followed by Hector Neris, JP France, Justin Verlander, Ryan Pressly, Framber Valdez, and Bryan Abreu. Notice that included here are your numbers one (JV) two (Framber), three (El Reptil) and four starters (JPF), as well as the consensus seventh (Neris), eighth (Abreu), and ninth-inning (Elvis) pitchers.

What this tells me is that I may actually be on to something here. Maybe not entirely coincidentally, these seven pitchers recorded seven of the best nine WHIP metrics on the team, with only France (1.357) over the MLB average of 1.298. Also, six of the seven best ERA+’s are represented by this group of seven (outliers are Phil Maton, in third with 141 despite his pedestrian 4-4 record) and the reptile, who somehow recorded a 92.

Conversely, Hunter Brown, Ryne Stanek and Rafael Montero graded out as the only pitchers who posted a record that was more than one game below .500. In addition, Stanek met the ignoble challenge of finishing the season with zero wins.

The experiment shook out thusly:

2023 Houston Astros W-L record by WPA

Christian Javier 10-2
Hector Neris 11-3
J.P. France 10-3
Justin Verlander 4-2
Ryan Pressly 11-6
Framber Valdez 11-7
Bryan Abreu 5-4
Jose Urquidy 2-2
Phil Maton 4-4
Brandon Bielak 5-5
Kendall Graveman 3-4
Seth Martinez 2-3
Hunter Brown 9-14
Luis Garcia 1-2
Rafael Montero 2-6
Ryne Stanek 0-2
Matt Gage 0-1
Ronel Blanco 0-1
Parker Mushinski 0-1

This is a statistic that I mean to keep checking on, but not for like, five months unfortunately. I guess there’s other things to do during the offseason, like football (stares blankly), hockey (shrugs discontentedly) and basketball (shudders imperceptibly). Thanks for reading.