This ESPN Stats & Info blog post (“a must-read for everyone at ESPN”!) is too much to bear, so off we go, Fire Joe Morgan-style …
In all likelihood, 24-year-old Stephen Strasburg’s season will end within weeks with the Washington Nationals likely in a fierce pennant race.
If the Nationals were to reverse course and allow Strasburg to pitch, would the workload hurt his performance? History suggests it wouldn’t.
No one is asking or even wondering this, because the question isn’t if Strasburg would struggle in September-October; the question is if he’ll eventually suffer another major injury from throwing too much too soon.
What the Numbers Say
Since 2001, 20 pitchers fit the profile of a young arm with a considerable workload. The criteria:
• The pitcher needed to be 23 years old or younger.
• It was the pitcher’s first season throwing 150 innings.
• The pitcher had not previously thrown 150 innings in his pro career.
There’s kind of an important bullet point missing here. Can’t quite put my finger on it, though. Something to do with elbow ligaments.
Did their performance from the beginning of the season until the end of July differ from their performance from August until the end of the season?
In general, the answer was no. In four of the five categories analyzed (ERA, strike percentage, miss percentage and WHIP), the median performance change was no more than five percent, a modest change at best.
If there is any trend, they improved their strikeout-to-walk ratio by more than 30 percent. Otherwise, their statistics lack a clear pattern, despite the polarizing nature of the innings-limit debate.
Again, no one’s asking this. What’s in question is the best course of action to increase the chances that Strasburg pitches like Strasburg for many seasons to come.
Even the following season, there was no defined trend — only two of the 20 pitchers missed significant time (Brian Matusz last year, Michael Pineda this year). This provides evidence that the “risk of injury” argument is somewhat unfounded. One-quarter of these pitchers have won the Cy Young Award, and 16 of them are still active major leaguers.
In short, there appears to be little risk to letting Strasburg finish the season from a statistical perspective.
Unless, maybe, Strasburg is less than two years removed from a major surgery that has somehow remained unmentioned.
The Tommy John Effect
Eight years before Strasburg underwent the noted surgical procedure, then-Marlins pitcher A.J. Burnett had Tommy John surgery.
After missing the first two months of the season, Burnett returned on June 4, 2004, and threw 120 innings. Until the end of July, Burnett was 2-5 with a 4.40 ERA.
However, in his final seven starts, he was 5-1 with a 2.74 ERA. That stretch also saw improvements in his command, suggesting that it took Burnett a few weeks to get his “feel” back.
The good news is we’re finally talking about Tommy John. The bad news is we’re talking about one case, and it’s a case where the guy threw 120 innings in his first full-ish season back. Strasburg has already thrown 127.
A more recent case is Washington Nationals pitcher Jordan Zimmermann, who had the surgery in August 2009. Upon his return, his numbers were alarming — fewer than 4.5 innings per start and a 4.94 ERA in his seven 2010 starts.
Last year, much like Burnett in 2004, Zimmermann started off rusty, going 2-6 with a 3.88 ERA through May. From June 1 until he was shut down at the end of August, Zimmermann went 6-5 with a 2.75 ERA.
This year ZNN is one of the best starters in baseball, and the Nats seem to be handling Strasburg in similar fashion. Meaning, I’m not sure this strengthens the ESPN Stats & Info blog’s argument.
These cases suggest that pitchers coming off Tommy John surgery tend to get better with time. The fact that Strasburg pitched with such dominance indicates that he got his “feel” back sooner than most.
One cannot expect him to improve this late in the season like Burnett and Zimmermann did, but one cannot predict a decline either.
NO ONE IS PREDICTING THIS.