Last week, I looked into the strange fact that starter usage hasn’t declined as precipitously as it first seemed over the past half decade. It’s downright strange that pitchers are throwing nearly as many pitches per start as they did in 2019 because it sure doesn’t feel that way. It’s even stranger that the average start length has declined by a mere half inning since 2008; I’m still scratching my head about that one even though I’m the one who collected the evidence. One potential answer stood out to me: maybe I was just measuring the wrong thing. Meg Rowley formulated it a bit better when we discussed the article: Maybe by capturing all the pitchers in baseball, I was missing the change in workloads shouldered by top starters. In other words, no one remembers the pitcher who made the 200th-most starts (Xzavion Curry in 2023, Ryan Tucker in 2008), and the usage patterns of back-end starters don’t leave much of an impression in our minds. We care about the horses, the top guys who we see year after year. Time for a new measurement, then. I took the same cutoff points from last week’s study, which serves to control for early-season workloads. But I further limited the data this time. I first took the 100 pitchers who had thrown the most innings in each year and called them “established starters” for the next year. Then I redid my look at pitch counts per start and innings pitched per start, but only for top pitchers in each year. In theory, this handles the pitchers we’re interested in: rotation mainstays who are still good enough to get major league jobs. Through April 30, the cutoff point for my study, there had been 904 starts in the majors. “Established starters” made 407 of those, which feels like roughly the right cutoff. How has those guys’ workload changed? Eh, basically the same as everyone else’s:
Established Starter Usage Change, Pitches/Start
| Year | Established Starter Pitches/Start | All Pitchers Pitches/Start | Gap |
|---|---|---|---|
| 2008 | 96.2 | 93.5 | 2.7 |
| 2009 | 97.6 | 95.2 | 2.4 |
| 2010 | 99.3 | 97.6 | 1.7 |
Note: All tables in this article use starts from roughly the first month of each season to capture early-season usage patterns
Established Starter Usage Change, IP/Start
| Year | Established Starter IP/Start | All Pitchers IP/Start | Gap |
|---|---|---|---|
| 2008 | 5.99 | 5.75 | 0.24 |
| 2009 | 6.04 | 5.78 | 0.26 |
| 2010 | 6.10 | 5.91 | 0.19 |
Yes, very good starters throw both more innings per start and more pitches per start than their less-qualified counterparts. No, that relative usage gap isn’t changing. For the last two years in aggregate, starters are down an average of 9.2 pitches and .67 innings per start from the numbers they averaged from 2008 to 2014. Among established starters, the top 100 group, they’re down 8.8 pitches and .68 innings per start. Cut it off at the top 50, and they’re down 9.6 pitches and .69 innings per start. Go even further to the top 25, and it’s 9.8 pitches and .7 innings per start. There’s a bit of a signal there, but it’s small. Half a pitch per start of difference between the league as a whole and its best arms isn’t quite the smoking gun I was hoping for to show that elite pitcher behavior is evolving differently than the rank and file.
