Update on Starting Pitcher Innings and Regression Risk
Updating Probable Workload for Starting Pitchers Blanco, Brown, and Arrighetti and Evaluating Regression Risk
My June 17 article detailed work load issues for three starting pitchers (Hunter Brown, Spencer Arrighetti, and Ronel Blanco). The gist of the article was that the Astros’ limited starting pitching depth would make it difficult to moderate the work load of pitchers who are likely to exceed their previous high season work load.
I discussed several options at that time for relieving the pitchers’ work load in the future. One option was the return of Lance McCullers Jr. and Luis Garcia from the IL. However, subsequent events dispelled that option. Another option was trading for a starting pitcher. The Astros subsequently did take that essential step, trading for Yusei Kikuchi. And in fact, the recent return of Justin Verlander from the IL and the acquisition of Kikuchi enabled the Astros to utilize a 6 man rotation, which provided some relief for the work load issue.
In the early summer article, I projected future innings pitched for Brown, Arrighetti, and Blanco, arriving at the conclusion that Arrighetti and Blanco faced a higher liklihood of exceeding their previous season high by more than 30 innings, which is a common benchmark. Since the article estimated future innings pitched by simply trending the previous innings pitched to that point in the season, the evaluation was a very rough approximation. Therefore, updating that analysis with one month remaining is a useful exercise.