Terminal velocity: Quantifying pitcher elbow injury risk based on fastball variance


Pitching accidents are the most important hazard in fantasy baseball, and elbow accidents are chief amongst them. What if there was a technique to objectively quantify who’s extra seemingly and fewer prone to endure such accidents?

We know that max effort is the best reason behind elbow injury. To be clear, not how arduous you throw, however throwing the toughest you possibly can throw, nevertheless quick that could be. We even have nice velocity information for all pitchers. What if we stipulate that the pitchers with common velocity closest to their max velocity are throwing extra ceaselessly with max effort? Conversely, those that have their common furthest from their max velocity are much less ceaselessly placing all the pieces into their choices. That offers us an elbow inexperienced mild and yellow mild (possibly a crimson mild relying on the way you’re persuaded right here) when score pitchers.

Before divulging the checklist based on 2022 velocity information, let’s broaden a bit of on the thesis with the assistance of a prime medical skilled, Glenn Fleisig, director of biomechanics analysis on the American Sports Medicine Institute (ASMI). Back in 2017, I equally used velocity information in a story for The Wall Street Journal on the rise in career-threatening elbow accidents.

This is what Dr. Fleisig informed me then for that article:

“If a man tops off at 96 and pitches the entire sport (there), he’s including much more stress on his elbow than if he varies his velocity,” says Dr. Glenn Fleisig, analysis director of the American Sports Medicine Institute.

Dr. Fleisig compares the physique’s ligaments — just like the one within the elbow that tears and requires pitchers to overlook a season recovering from Tommy John surgical procedure — to a rubber band. Pull it again as arduous as you possibly can and it’ll begin to tear. Pull it much less, he says, and “you’d by no means tear the rubber band.”

I not too long ago confirmed with Dr. Fleisig that that is nonetheless the working concept for elbow accidents. He additionally stated a max-minus-average metric like we utilized in that article was nonetheless an inexpensive technique to assess relative risk.

The information we’re utilizing right here is totally different. Then, we had max and common velocity for the entire sport. Now we now have extra apples-to-apples comparisons in varied pitch strata (pitches 1-to-20, 21-to-40, 41-to-60, and many others) via SimpleBet, which makes use of machine studying and real-time know-how to “make each second of each sporting occasion a greater alternative.” (This information is collected to tell folks wagering on the rate of the subsequent pitch for a particular pitcher. But we’re utilizing it right here to evaluate injury risk for the upcoming season.)

The low finish of velocity variance between max velocity and common velocity is about two miles per hour or much less. The excessive finish is about 4 mph or extra. Again, extra variance between max and common means the pitcher isn’t maxing out as usually along with his fastball, and fewer means he’s in all probability throwing full tilt extra usually, which results in larger injury risk.

To be clear, any pitcher will be injured on any pitch. We need everybody to be wholesome. This is merely an try and merge the science of elbow accidents with the target information, as greatest as we presently can. This isn’t binary — I’m not saying some guys are secure and others are pitching on borrowed time. It’s not black and white. It’s nearly chances. Who is pitching optimally in line with the science of elbow accidents and who’s pitching sub-optimally?

When we did comparable (although not an identical evaluation) within the Journal in 2017, the pitchers who had been recognized as having larger elbow risk had been: Steven Matz (subsequent elbow surgical procedure in 2017), Noah Syndergaard (Tommy John surgical procedure in 2020), Michael Fulmer (Tommy John surgical procedure in 2019), Jameson Taillon (Tommy John surgical procedure in 2019), Stephen Strasburg (subsequent elbow impingement in 2017). However, the secure pitchers didn’t fare nice. Carlos Martinez had unrelated (in line with the science) shoulder surgical procedure and Chris Sale had 2020 Tommy John Surgery (however that was after 1,629.2 profession innings, excess of anybody within the risk group who was recognized).

Here’s the list for the info from 2022, once more courtesy of SimpleBet.


Let’s take a look at the blokes getting a inexperienced mild.

Freddy Peralta is red-flagged for accidents in our sport, however his points have concerned the shoulder, a unique sort of injury not coated on this evaluation. We’re merely giving his elbow a inexperienced mild given how he’s the most effective proper now at various his velocity. And once more, it’s not as a result of he loses velocity because the pitch rely will increase since that is the typical of the max vs. common in all of the 20-pitch strata (1-to-20, 21-to-40, and many others.).

Max Fried is doing it the correct method. I like this strategy for such a younger pitcher and I additionally assume, and that is with out information to again it up, that various fastball velocity is definitely a great fastball technique. (I need to be aware that max effort on all pitches, I’ve not too long ago discovered from Dr. Fleisig, is a precursor to elbow injury — we simply use fastballs as a result of we now have probably the most information on them.)

Michael Kopech has already had Tommy John surgical procedure. Maybe he’s various his velocity consequently, or possibly that is his plan to keep away from a second reconstructive surgical procedure, very seemingly a profession dying blow.

I don’t need to make an excessive amount of of David Peterson as some aid innings are blended in right here. But trying on the pitches throughout the pitch-number vary does mitigate issues right here. Peterson can throw shockingly arduous given his repute however that shouldn’t trigger considerations given his stable fastball variance.

Shohei Ohtani additionally could also be adjusting to a previous Tommy John surgical procedure. If that is his response, it’s clearly an excellent one which the medical group typically helps. Again, old fashioned, Ohtani’s elite velocity could be an amazing concern however this strategy proves that he can throw a lot more durable than he does on common, lowering concern about elbow stress.

Carlos Rodón is right here sarcastically since he has elbow points now. We can’t give him a inexperienced mild clearly, however I’m not going to provide him a crimson one since he’s apparently attempting to fluctuate his effort when he pitches. The takeaway is that for those who drafted Rodón at his post-injury ADP, this information says you made an inexpensive guess.

Nathan Eovaldi additionally has a protracted injury historical past however has averted issues along with his elbow since 2019. He’s good when wholesome and the Rangers may very well be a great workforce, so I like his 200+ ADP much more given this information. But, keep in mind, he had shoulder points in 2022.

Kevin Gausman is like the brand new Justin Verlander in the best way he proactively varies his velocity. That’s possibly why he can survive as mainly a two-pitch pitcher with the splitter, despite the fact that the fastball was not very efficient in line with Statcast final 12 months. Still, the general pitching arsenal works.

Robbie Ray will get Ks with out max effort, possibly that improves his management, too. Ditto for Gerrit Cole, who looks as if a horse in how he defies the injury odds — and this provides us a window as to why. Verlander has at all times been the fashionable poster participant for dialing up the fastball when wanted. He’s nonetheless doing it after getting back from his late-career Tommy John en path to having arguably his greatest season.

Spencer Strider and Yu Darvish are within the secure zone. Strider has dimension considerations (actually simply peak, as he’s constructed like a wrestler). You would assume he’s maxing out to generate his four-seam common, however you’d be unsuitable. Darvish is so underrated off his 2022 season. He throws seven pitches and that doesn’t even embrace these fastballs of various speeds.


I’ve a share of post-oblique Tyler Glasnow someplace and now I want I didn’t. I’m anxious that elbow goes to be barking periodically, although the recency of the surgical procedure in all probability prevents one other tear. He’s simply not doing himself any favors. I do know the pattern of knowledge final 12 months was small, however how a lot do you want? He’s in all probability max effort.

While Hunter Brown has been sidelined with a again injury, I fear about his elbow. Remember, he throws 93-mph sliders and maxing out on these is horrible, too. Add the additional adrenaline with being within the majors and I’m anxious the rubber band is no less than going to over-stretch if not snap.

Jacob deGrom is programmed to throw 100 mph on each pitch. It drove me loopy after I watched him right here in New York. You don’t must go all-in on no less than half the hitters. He ought to relax. This is the most important cause to count on one other DL stint this 12 months.

I feel the park is the large cause to not draft Nick Lodolo. But his max-minus-average hole is so small. For comparability’s sake, Hunter Greene’s is 3.3 mph, about 50% extra. Greene throws more durable however his elbow has much less risk than Lodolo’s.

Similar to Glasnow, I don’t assume Dustin May discovered his lesson. The Dodgers are all-in seemingly on max effort. You have proof of this final 12 months with Walker Buehler earlier than his Tommy John surgical procedure, and Clayton Kershaw appears to be maxing out. And even Washington’s Josiah Gray (2.3 mph) grew up within the Dodgers system.

Jeffrey Springs is a sabermetric darling. All the analytics guys like Springs. I’ve shares. I’ve written about him as a cut price earlier than his ADP spiked, particularly in high-stakes leagues. But I’m throwing a bit of warning out right here. I’m not saying Springs goes to get harm, however he does profile like a pitcher who’s maxing out/tempting elbow woes.

The final man is Lance McCullers Jr. His 2.5 mph wouldn’t be that noteworthy nevertheless it’s proper on the sting of fear and he already has an elbow subject. So anticipating him to get better after which throw full bore quite a lot of the time is simply an excessive amount of risk even at his depressed ADP.

(Top picture: Ben Ludeman/Texas Rangers/Getty Images)