The Change: Sinkers, Injuries, and Defense

After all of our focus on injury rates due to sliders and curves, which were good efforts but produced small results, it’s interesting to consider sinker usage as a possible marker for injury. Bill James did so, famously, a while back. He thought that ground-ball pitchers were only good for a short while, and then injured.

The response was swift from the saber metric crowd. Bill Petti couldn’t find an effect. Russell Carlton looked into injury prediction and found the following as important to shoulders. You’ll notice that ground ball rate is not included.

“First, shoulder injuries. In order of strength of prediction, the best predictors of whether or not you will have a shoulder injury in the coming year are whether you had a shoulder injury last year, how many pitches you threw last year, whether you had a shoulder injury two years ago, how many extra batters you faced last year from the year before (with a greater increase meaning that you were less likely to be injured), and the two-strike foul rate (just barely).”

Still. Let’s look at the top sinkerballers of the last three years. Perhaps sinkers are the source of the issue, not straight ground ball rate. You can get a ground ball with your secondary stuff, after all, and there is something about the sinker that combines internal shoulder rotation and big velocity that might actually be mechanically risky.

Heavy Sinker Starters, Last Three Years

Name	IP	FT%	DL Last Year?	Age	Projected IF RS	RG Rank
Charlie Morton	402	59.1%	1	32	-19	136
Scott Kazmir	531	52.2%	0	32	5	35
Bartolo Colon	587	51.4%	0	42	-17	114
Henderson Alvarez	312	50.6%	2	25	-13	188
Joe Kelly	354	49.9%	1	27	2	123
Chris Sale	597	49.8%	1	27	-2	3
Doug Fister	475	44.3%	1	32	-5	141
Kyle Gibson	425	40.0%	0	28	-4	103
Tanner Roark	363	37.7%	0	29	-3	163
Cliff Lee	304	37.5%	1	36	n/a	#N/A
Francisco Liriano	510	36.4%	0	32	-6	25
Dallas Keuchel	585	35.9%	0	28	-5	15
Wade Miley	597	34.7%	0	29	-2	84
Jeff Locke	466	34.7%	0	28	-6	129
Alfredo Simon	471	34.7%	0	35	n/a	183
Jordan Lyles	317	33.1%	1	25	6	193
Rick Porcello	553	33.0%	1	27	2	70
Aaron Harang	520	32.8%	1	38	n/a	187
Wily Peralta	490	31.9%	1	27	-8	131
David Price	655	31.9%	0	30	2	4
Dillon Gee	376	30.8%	1	30	8	#N/A
Gio Gonzalez	530	29.2%	0	30	-3	51
Erasmo Ramirez	311	28.2%	0	26	0	92
Jake Peavy	458	27.7%	1	35	23	88
Chris Archer	535	26.6%	0	27	0	17
Jon Niese	507	26.1%	0	29	-6	124
Tyson Ross	516	25.5%	0	29	-14	21
Andrew Cashner	483	25.1%	0	29	-14	52
Mark Buehrle	604	25.0%	0	37	n/a	153
Yovani Gallardo	557	24.7%	0	30	23	96

Projected IF RS = projected infield runs saved, averaged between ZiPS and Steamer projections.
(From August Fagerstrom article here)
RG Rank pulled from last RotoGraphs Rank here

It’s hard to escape the allure of the anecdote here. Henderson Alvarez is today’s Brandon Webb, only with a shorter grace period before the injuries set in. Charlie Morton and Scott Kazmir have dealt with their share of injuries. Doug Fister, Francisco Liriano, Jake Peavy… there’s enough fire here to think there’s smoke.

But research suggests the “DL Last Year” column is the most important one, so worry less about Dallas Keuchel and Erasmo Ramirez then Charlie Morton and Doug Fister. That probably fits with your world view, anyway.

But how about this. Sinkerballers allow more balls into play, and so are therefore more subject to the whims of the defense behind them. Sort the list for that projected infield defense (in reverse) for a second.

Whoo boy. Sell your shares of Charlie Morton, it looks like. That worm-burner left the relatively safe confines of Pittsburgh for a really bad infield defense in Philadelphia. Who knows what kind of role Bartolo Colon will have, and he won’t be depended on by many in real life or fantasy.

But look at that next duo in San Diego. They’ll be drafted high, they use sinkers a ton, and they’ll probably be in front of a bad infield defense. Will Alexei Ramirez make things better for Andrew Cashner or Tyson Ross? Maybe. His numbers and athleticism have been an impressive decline over the last two years, though. Yangervis Solarte is not a great fielder, Cory Spangenberg might be the only scratch defender on the infield, and Will Myers will be learning a new position. The backups are no better.

Both Ross and Cashner had bad infield defense numbers last year, and both have been tagged for injuries in the past. Even if the injury component of their projection is based only on smoke, the real-life bad defense behind them makes them slightly worse bets than you might expect.