May 29, 2015
Where Have You Gone, Stephen Strasburg?
Stephen Strasburg’s season has been a frightening experience for me, not just as a Washington Nationals fan but also as a sabermetrician. Dissecting the reasons for his season-long struggles is not easy. To begin with, my brain is struggling with how much of his 6.50 ERA to attribute to bad luck and how much to bad pitching. Matt Trueblood took a good crack at exploring the issue a few weeks ago. Ben Lindbergh and Sam Miller touched upon it earlier this week in their podcast, and left with no good explanations; they concluded it was likely just a random rough patch in his career.
The numbers don’t really point to a strong conclusion. Some of the peripherals say he’ll be fine, and others say he’s in real danger.
Some signs he’s okay include the following:
And some signs he’s in trouble:
With the season still relatively young, and the sample sizes still uncomfortably small, I opted for a qualitative approach. Namely, I re-watched all of his starts. Every pitch. I took notes on things like sequencing, command, and other little things worth nothing, and I have my shorthand game summaries below. Every run-scoring play is broken down briefly. Building up from the granular pitch-by-bitch level, I looked back to see if any major trends emerged. Skip to the end if you don’t want the minutiae.
April 9th vs New York Mets:
Game Score: 34
April 14th vs Boston Red Sox:
Game Score: 33
April 19th vs Philadelphia Phillies:
Game Score: 69 (nice)
April 25th vs Miami Marlins:
Game Score: 44
April 30th vs New York Mets:
Game Score: 54
May 5th vs Miami Marlins:
Game Score: 43
May 12th vs Arizona Diamondbacks:
Game Score: 16
May 17th vs San Diego Padres:
Game Score: 51
May 23rd vs Philadelphia Phillies:
Game Score: 27
So, that’s everything.
The first thing I looked for over the course of the season was whether I could assess his .390 BABIP and high run totals as a result of bad luck or bad pitching. For the most part, I’d have to call it the latter. Only in the April 9th start would it be fair to say that Strasburg's stat line was an unfair reflection of his pitching performance. Few of the hits he surrendered were bloopers or seeing-eye singles. There was a lot of solid contact. Also, just about every run-scoring inning was a multi-run jam up (with the exceptions of solo home runs). He has rarely been able to stop the bleeding.
The real story for me behind all of it has been the lack of touch on his curveball and changeup. You may have noticed Strasburg is throwing more fastballs than ever this year, but that’s probably not part of the game plan. It’s likely a reaction to the fact that his curve and change are much less effective, and there’s no real backup plan when that happens. In only one start and in brief flashes in other games was Strasburg able to throw his secondary pitches for strikes. Instead, they often turned out to be non-competitive pitches or meatballs.
It’s only after having watched his whole season that I found statistics that tell the story. Below is a chart comparing his pitch outcomes by pitch type, 2010–14 in black and this season in red/green. Red and green just mean increase or decrease, not necessarily better or worse. Remember, these percentages are of all pitches thrown in that type:
It’s obvious that Strasburg's changeup has lost a tremendous amount of effectiveness this year. Over half of them in the 2010–14 period were called or swinging strikes, while this year it’s just 34 percent. Likewise, 55 percent of his curves were called or swinging strikes in years past, but this year it’s just 44. Meanwhile, his fastball is being thrown more often, at the expense of a higher foul rate and fewer whiffs.
Strasburg’s heater hasn’t been all bad, considering. It still has above-average velocity and often has the explosiveness needed for swings and misses. Having a 96 mph fastball with movement is like commanding an army that features an awesome tank corps. Those tanks are an essential part of your armed force, but their actual utility will be limited without infantry and artillery support. For the most part of the season, Strasburg has been a one-trick pony.
I can’t tell Stephen Strasburg what he needs to be successful, but I can describe how he looks when he is. He mixes pitches with ease, using any pitch in any count to keep hitters off balance. He’s able to come up with swing-and-miss pitches when he needs to, but he can also count on a fair number of called strikes. He can work a lineup three times over because hitters won’t have seen too many pitches to get comfortable.
This year, none of that has been the case.