Schilling’s aching shoulderby John Walsh
June 26, 2007
On June 18, Curt Schilling got cuffed around by the Atlanta Braves. He lasted only 4.1 innings, surrendering 10 hits and six runs, walking two and striking out nobody. The last time Schilling failed to strike out a batter in a start was in 1993. Of course, anybody can have a bad day, but this was clearly more than that.
It was obvious to everybody that Schilling's velocity was down. And not just down a mile or two per hour, but way down. Here's what Braves third baseman Chipper Jones had to say:
I think we all expected to see 92, 93 (miles per hour) when he gets in trouble, or even hike it up to 94, 95. The fastball that I saw register the highest was 89, and that was with the bases loaded. Schill always had that innate ability to catch another gear when he needs it, and for me to only see 89 miles an hour tells me, you know, he might be hurt. I don't know.Later, Sox beat writer Gorden Edes of the Boston Globe reported:
In Monday's 9-4 loss, Schilling threw only one fastball that exceeded 90 miles per hour, a 91-mph pitch to Kelly Johnson with the bases loaded in the fourth.
Schilling was sent back to Boston for an MRI and the results showed "no structural damage." Aside: What is "structural damage"? Is there nonstructural damage that we should be worried about? Anyway, Schilling says he hasn't felt pain in his shoulder, although clearly everybody is worried that there is some problem.
The Boston pitcher was given a cortisone shot in his right shoulder and the word is that he's suffering from tendinitis, which I think is what they usually say when they don't know what's going on quite yet. Or don't want to tell.
So, why am I, an analysis guy, writing about Schilling's medical problems? Well, I thought I might have a look at the pitch data available from his difficult start to see if we can learn anything. First, we should easily see his loss of speed, but we can also check pitch movement, release point and maybe some other stuff as well.
Let's start with pitch speed, which everybody noticed right off the bat. Did Schill really top 90 only once in the outing? Yes, and here's a graph to show it:
By the way, both Jones and Edes were accurate in their statements. Jones identified Schilling's fastest pitch of the night and he also mentioned that Schilling gets to 93-94 when he needs to. Edes said only one pitch topped 90 mph, that a 91 mph fastball thrown to Johnson with the bases loaded. That pitch was measured at 90.3 mph by Enhanced Gameday and it was indeed thrown to Johnson with the bases loaded. Johnson flied out.
Pitch selection and movement
So, Schilling clearly was not throwing as hard in his last start, but we can ask more. Did Schilling modify his pitch selection, based on his lack of stuff? Are all those pitches in the 78-86 mph range just slow fastballs or did he go to the slider more often? And did his pitches have less movement in his last start, in addition to a loss of velocity?
Before we can answer these questions, we need to look at what kind of pitches Schilling normally throws. The plot on the right shows the vertical and horizontal movement for the 162 pitches captured by Enhanced Gameday previous to his last start (see my previous article, In Search of the Sinker for background information on plots like this).
The green points are fastballs and the black ones are curves, while, the red points are a mix of sliders and splitters. The splitters are more toward the left of the red cluster, while the sliders are toward the right, although there isn't a clear separation.
Now, we can look at the the same plot for the start of June 18. Actually, what is shown below is the same plot we just saw, with the additional pitches added (solid dots).
Also, if you look closer at the red points, there seem to be fewer, at larger negative values of horizontal movement—Schilling seemed to avoid the splitter in that start. The fastballs also show less movement in this last start, although I believe that is consistent with them being slower.
It is sometime said that a pitcher will lower his arm slot if he has a shoulder injury. The Enhanced Gameday measurements include the (x,y) coordinates of the release point for every pitch. This graphic shows Schilling's release points for the Atlanta start (red points) and his previous starts (black). The y-axis records the height above the ground (in feet) of the release point. The horizontal position is measured relative to the center of the pitching rubber.
Wow, those red points are consistently shifted with respect to the black ones. Schilling doesn't appear to be lowering his arm slot, but he does seem unable to get proper arm extension. But you know what? When I saw this plot, I was a little suspicious about the data. THT's John Beamer has already shown that we need to be aware of possible inaccuracies in the data. I think the release point is one of the harder things to get right across stadiums, while other measures like velocity, movement and location are probably more accurately recorded.
In any case, I thought it prudent to check the release point data by searching for other pitchers who have data recorded in Atlanta plus other parks. The plots below show the release points for three additional pitchers, red dots for starts in Atlanta, black dots for starts in other parks.
The release point data might be hinting at something, though. Perhaps we can't trust the shift in release point that we see, but I'm guessing that the large spread in Schilling's red points compared to those of the other pitchers is probably a real effect. It looks to me like Schilling's release point was wandering around that evening in Atlanta, much more so than in his previous starts.
Obviously, a loss of command doesn't necessarily imply an injury; some days you just don't have good command. Still, I thought it'd be interesting to look at what happened on each of Schilling's pitches, both in his last start and in previous starts. Here is a table of the numbers:
Pitch Results Previous June 18 -------- ------- Ball 49 (.30)* 30 (.38) Called 40 (.25) 11 (.14) Swinging 14 (.09) 3 (.04) Foul 21 (.13) 15 (.19) In Play 37 (.23) 21 (.26) Total 161 80 *Numbers in () are the fraction of total."Called" and "Swinging" refer to strikes, of course. It's clear from these numbers that Schilling also had a tough time commanding his pitches in Atlanta. He threw more balls (in terms of percentage) and had many fewer called and swinging strikes—he induced only three swing-throughs in 80 pitches that night.
He allowed a higher proportion of balls in play and of those 21 balls in play, 10 went for hits, including two doubles and a home run—a scary combination of loss of stuff and loss of command. Of course, we shouldn't be surprised that Schilling was rattled a bit when he realized that his fasty was coming in 5 mph underweight.
Some people, including Sox manager Terry Francona, have mentioned age as a possible reason for Schilling's struggles in Atlanta. That seems pretty odd to me, since Schilling was only 12 days older than when he threw a one-hitter in Oakland, and nobody was worried about Schilling's age then. I suppose Francona was just dodging the question about a possible Schilling injury.
We won't really know what happened to Schilling until he tries to start throwing again in a couple of weeks, or maybe not even then. I, as a Sox fan, am pretty worried, although I guess being worried is part of being a Sox fan in the first place.
John Walsh dabbles in baseball analysis in his spare time. He welcomes questions and comments via e-mail.