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By bwoodrum | at
Email a copy of 'Predicting Tommy John Surgeries' to a friend
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dboduch
R.A. Dickey does not have a Ulnar collateral ligament (UCL) and therefore cannot have Tommy John.
Tim Dierkes
Nice catch. Kind of a one-off though, this model is saying he’d be among the lowest risk even if he did have a UCL. Bradley didn’t build in a “does he have a UCL” variable or anything.
bwoodrum
Haha! I didn’t even think about that!
Well, I still stand by my research, and I may catch some heat for this, but I am officially predicting R.A. Dickey will not have a major UCL injury this year.
dboduch
And you’re right – I guess that means the predictability model is fairly sound!!!
kachur7
This is great work, kudos. I’m curious if your research led you to see a sudden velo spike as a red flag right before TJ? I recall Keith Law calling that with Danny Duffy a couple years back. Thanks.
Jeff Zimmerman
I attempted to answer this very statement here: hardballtimes.com/velocitys-relationship-with-pitc…
kachur7
Oh man, bang on. Thanks, i really enjoyed your work.
bwoodrum
In all fairness, the editing staff added that after his comment.
greglowcws
He does mention that in this arrival, but he said he included him anyway
wilymo
look right above you – that was added to the article later, because of these comments
georgebell 2
Glad to see Dickey has negative risk given that he lacks a UCL to repair.
sfarstad
Great article, but considering that R.A. Dickey doesn’t even have a UCL in his pitching arm, he should probably be last on the list.
A'sfaninUK
Wow, what a post!
adyo4552
Agreed – Excellent work Dr. Woodrum! Please continue producing original informative research like this article. Again, great job.
batman
Awesome stuff! Ill have it more in-depth after work. I like the dummy variable for LHP, but what about on for height? More specifically looking at either smaller or larger pitchers?
This is something that hits close to home for me, I actually did my Econ Sr. Thesis on this exact issue 🙂
bwoodrum
Height was a real iffy variable for me (I actually meant to include it in the writeup, but forgot). It missed the cut by a single model version. I suspect there is a role height plays into it, but I wonder if height is also just impacting velocity, which impacts Hard Pitch usage. When I incorporated Hard Pitches, height became effectively useless — though I can’t say there’s a direct causation there.
batman
Thanks for the response! And yeah I could definitely see that. Itd be interesting (at least for me anyway) to see if the hard throwing short guys actually do have that elevated risk that they seem to be perceived with. Again, great work and an tremendous read!
wedgeant27
Joining the chorus of “excellent posts” but as a former college pitcher who is 6’8″ I’d have to imagine that height also directly impacts UCL length in the arm. Perhaps to be more precise, a metric for forearm/upper arm length may be somewhat predictive? A bigger guy may actually put less stress on the ligament as there’s more of it to absorb the strain.
dirtymike
Could you go back and see what the effect was of the mound height and its change?
maddog3119
It does my heart good to see Jake arrieta so low
ironwolf
Me too. I own him in a fantasy keeper league. But even though his risk for a severe UCL injury may be low, my guess is that he’s still at high risk for some type of shoulder or arm injury—that slutter he throws is supposed to be hard on the shoulder. And he throws it a lot.
The bummer for me is Smyly. I own him in a deep league and was planning to keep him. To play it safe, maybe I should drop Smyly and keep Gio Gonzalez, even if his skills appear to be declining.
ilikebaseball 2
About the only thing I really learned was that if you’re approaching forty good chance you’ll grown another ligament in the throwing elbow. Where’s mine?
hanks1hammer
What list did you read? Archie Bradly, Jose Fernandez and Drew Smiley are all under 28 and listed has high risk and those are just the pitchers I know off the top of my head.
ilikebaseball 2
And I ask you, What comment are you responding to?
hanks1hammer
Yours. I don’t see how you take from this article that it’s saying pitchers over 40 are high risk for tjs. If you were reading this article, you would see both older and younger pitchers are on both sides of the risk factor
Bobby Sweet
That wasn’t, in any way, his comment. He quipped – as Bradley did – that pitchers over the age of 40 naturally GROW extra UCLs, thereby avoiding serious injuries.
TheMichigan
Little question how can Dickey have no UCL and still pitch? I know he’s a knuckleballer buy still he throws a fastball on an off chance
mattymets
This is fantastic work. I’ve been waiting for someone to expand on the “Verducci effect.” I saw one tremendous flaw in your analysis. Before you dismiss me, let me point out that I am a baseball coach, blogger and former pitcher. The most important tell tale sign of a coming elbow injury is bad mechanics. I watch for pitchers who put too much stress on their arms. I teach young pitchers that you get your power from your legs and your upper back – not your arm. I have them watch video of Tom Seaver, Nolan Ryan, Mariano Rivera, etc. A fluid windup, a repeated delivery, a powerful drive toward homeplate, followed by a gentle, not violent whip of the arm. Guys who come across their bodies always blow out their elbows. I predicted future surgeries for Kevin Brown, Jake Peavy, Stephen Strasburg and Zack Wheeler (more because of the obvious inverted W in his case. Masahiro Tanaka has a similar issue). I’m not suggesting good mechanics alone can protect a pitcher from elbow injury, but bad mechanics put undue strain on the elbow and, I believe are the number one red flag for future TJ surgery. I’m no Frank Job and I am not an MLB coach, but I think I know what I’m talking about. I plan to make this the focus of my Friday blog post on mets360.com as I’m tired of reading about how Noah Syndergaard is next in line just because he throws hard and his innings increased.
adyo4552
mattymets – How would you objectively define “bad mechanics”? I think Dr. Woodrum has tried to take this factor into account with variables like Release Point, Arm Slot, and Arm/Shoulder Index.
mattymets
Addyo4552 – my point is that not every single aspect of baseball is quantifiable. That’s why, with all the algorithms and all the data, teams still hire scouts.
sessh
You hit the nail on the head. Inverted L, shoulder hyperabduction, timing issues, throwing too many sliders and curveballs and other mechanics related issues are thew biggest risk factor for arm injury. I watched this closely for years a few years ago and saw without exception that guys who were coming down with major arm injuries had huge mechanical problems particularly arm action. At footstrike, the arm should be up and in the ready position, but for many, the arm is not up and has to hurry to catch up resulting in tremendous forces being applied to the UCL. It is similar to throwing your car in reverse, flooring it and then throwing it into drive and flooring it without touching the brake pedal. That’s what guys are doing to their arms with every pitch who throw like this. Obviously, the harder you throw with these kinds of mechanics, the worse the effect is especially if you are an arm thrower. Mark Prior, Anthony Reyes, Shaun Marcum, BJ Ryan, Chris Carpenter, Yu Darvish among many others. It is a huge contributing factor. Prior had absolutely terrible arm action and BJ Ryan had the worst inverted L I’ve ever seen; both are out of baseball. Both Ryan and Marcum were also arm throwers with very short strides. This anaylsis completely misses these factors which unfortunately makes it flawed.
adyo4552
It is not flawed because it doesn’t pretend to account for everything. There is a note above about the statistics R^2 (R squared), which quantifies how much of the dependent variable (TJ surgery) the independent variables (all the factors that went into the model) can explain. R^2 for his model is .22. This means that only 22% of TJ surgeries are predicted by this model. So it is not appropriately to call the model flawed because it doesn’t taken into account every variable that you think is important. It just means that predicting TJ surgery involves lots and lots of factors, and his model has successfully determined 22% of them. Future versions of the model may add other variables in, like the ones you try to identify, which could raise R^2 as a consequence.
adyo4552
Please forgive my terrible spelling and grammar above. Apparently the edit button has vaporized.
newtonsthird
Biomechanist here. mattymets: pitching mechanics are quantifiable, via 3-D motion analysis. Things like joint sequencing, valgus torque about the elbow, and shoulder and elbow angles at release are generally evaluated by sports scientists within baseball. Though the technology isn’t available to do it yet on a pitch-to-pitch basis in a game, many teams do use this technology in their preseason or offseason as a means of evaluating their pitchers. However, to adyo4552’s point, the difficult part is in identifying ‘good’ from ‘bad’ in a meaningful and objective way. Biomechanics can identify differences between players and populations, but in order to identify something as being bad, you need to match it up with injury or performance in the long term. Coaches certainly have notions of what constitutes ‘good’ (remember when Mark Pryor was considered God’ gift to pitching mechanics?), but usually those determinations are made independent of rigorous scientific study. The only way that they will become a part of predictive models of injury is for more of those data to become available to the public, which most teams and players (AND AGENTS!) have a vested interest against.
bhersh03
I would think that the only way to quantify what is good mechanics vs bad would be to have a pain score. If someone is throwing without pain, then it’s gets pretty hard to say what is good vs bad. Also, what about high stress innings (higher than average pitch counts in an inning) vs just looking at hard pitches?
adyo4552
Not good news for the Yankees – Eovaldi, Tanaka, Severino, and Pineda are all at least 60% above average for future TJ.
newtonsthird
Fascinating read. One of very few published predictive models of injury I have seen for professional sports. You did a fantastic job both explaining the model in laymen’s terms and describing the inherent limitations of this type of research. In my opinion, too many ‘experts’ are stuck looking for a single scapegoat for catastrophic injuries in throwing athletes–whether it be poor strength and conditioning programming, pitches/innings, or ill-informed pitching coaches. As the paradigm continues to shift towards data-informed decision-making, I’m excited to see work like this become more a part of the discourse about players and organizations moving forward. Well done.
notagain27
I enjoyed your post. If there was anyway to add to your statistical analysis the amount of innings young pitchers ages 8-18 are throwing playing travel ball in the USA then your program would really have added validity. TJ surgery is a epidemic in our youth programs of today where pre-teens and teenagers alike are playing over 60-100 games a year. The damage being done may not show results of damage to their ligament until they have signed a professional contract but believe me, damage is being done. I also believe lefthanded pitchers may be more susceptible to the ailment because a higher percentage of those LHP’s throw across their body. Mechanics play a big part in players having shoulder and elbow issues.
ourgiants25
As a Giants fan I’ve noticed the team doesn’t get TJs and if you look at all Giants starters they are all among the lowest risk. Hmm… Does the team know something others don’t?
0-3
Before more people complain of Dickey being in here with no UCL, read the whole thing first ” (Dickey, of course, doesn’t have a UCL in the first place, though obviously the statistical algorithm in question doesn’t take such factors into consideration. We left his name in the results regardless of that fact, for those wondering why, as a means of illustrating the type of pitcher likely to rank low on the list)”
wilymo
they added that later because of the comments
0-3
Thanks for the info! I didn’t know that
slpdajab55
What a load of garbage- is there nothing better to occupy ones time. Completely useless and BS
southpaw2153
Completely agree.
maybeofftopic365
wait, how is Rafael Betancourt so low considering he sat out most of 2015 with an elbow injury and had TJS as recently as 2013. This seems like a weird result.
hozie007
The only variable factor that should carry less weight in the risk analysis is “Days Lost to Due Injury”. The reasons and number of days players are on the DL are not always what they seem. That said, the other factors such as ERA, hard pitches, etc. are real, verifiable numbers. I like the approach though……very well thought out. Another variable to consider would be “Number of stressful innings (more than say 20 pitches in an inning)”…this can really tax a pitchers arm especially if its late in the season and he is already feeling the effects of 12-15 games. …and pitching density where you evaluate the number of pitches thrown is a certain period of time……..
cxcx
Yeah, I also found the zero mentions of stressful pitches to be weird as that is the factor that has been most talked about in relation to pitcher health/durability over the past year.
I’m guessing it’s just another thing that the author forgot to include in the writeup because he found it unpredictive rather than it being something that he just neglected to look at. It would be good to know for sure though.
michaelg
Awesome study. What kind of regression was used? Logistic?
ketchup1popsicle
This was a very ambitious study. Very fascinating!
josec
Why didnt you include a starter/reliever variable?
Also I’ve always thought that having a pitcher starting games and turning him in to a relief pitcher, back and forth, could have negative impact on the pitchers arm.
Niekro
Is the LHP thing worded wrong or do I just not understand it? If they only make up 28 percent of pitchers but 25 percent of TJS wouldn’t that make them more susceptible?
Russell Sampson
I get what you’re saying, I had to re-read it myself after you mentioned it. But he does have it worded correctly.
If 28% of pitchers are left handed, then for then to be equally susceptible to the surgery as RHP, 28% would be the number that has them equally susceptible. Since the number is 25% instead, they are less susceptible than a RHP.
I was wondering whether or not we’d see DIckey on this list. I didn’t find it as funny that he made the list itself, so much as there is one person ahead (behind?) of him. I find it much more impressive that a single person has less of a chance of tearing their UCL than a guy who doesn’t actually have one.
danfromfreddybeach
That would make them less susceptible. They are a lower percentage of TJS than they are of the general pitcher population. They are 11 percent less likely to have TJS than right handers.
You could say that Lefties are 10 percent of the general population but 25 percent of TJS. That would make them more susceptible than the general population. However, this only really means that Lefties are 280 percent more likely to be in MLB than the general population.
Niekro
I’m pretty sure that is incorrect I’m no math expert but the only way what you are saying would make sense is if the total number of TJS is the same as the total number of pitchers in baseball and I’m pretty sure not every pitcher in the league has had a TJS, making up a little over a 1/4 of the league but being responsible for 1/4 of all TJS would seem to say they are more likely to get TJS.
Niekro
Look at it as Pies 28 percent of all pitchers in baseball is going to be a smaller slice of pie than 25 percent of all TJS surgeries in baseball.
Niekro
I realize that is the wrong way to look at it as a pie will be divided the same no matter what but what I am getting at is the total number of pitchers in baseball is a much larger number than the total number of TJS, You are looking at 28 percent of total pitcher population vs 25 percent of TJS the fractions would be much different.
Niekro
Say we have 1000 total pitchers 280 are left handed, we have 100 TJS 25 percent are left handed
25/280 LHP with TJS vs 75/720 RHP with TJS 11 percent of this LHP population had TJS vs 9 percent of the RHP
I don’t know the actual numbers and these are way off but this is how they should have got the correct percent
xtraflamy
I’d like to see this addressed by the author.
BlueSkyLA
Massively good work!
One question: My understanding is that at least anecdotally the overhand curve is one of the hardest on the shoulder over time, which seems to make sense when you consider the mechanics of the pitch. Were you able to track those kinds of injuries?
mike156
Beautiful work. I’d be interested in seeing it sorted by initial farm system.
wants to be a GM
Great job, guys. It’s a good starting point for hopefully what turns out to be a way to prevent these injuries.
danfromfreddybeach
Why doesn’t Adam Wainright appear in the full list?
southpaw2153
This is the biggest bunch of crap I have ever read. Couldn’t get past the first two paragraphs. There is absolutely zero way to quantify whether a player is going to need TJ surgery.
You mathletes can come up with all kinds of formulas but you’re never going to predict how a player is going to perform in a particular year or whether they will or will not be injured.
Same as sabermetrics. It’s nothing more than a guess. You might be able to talk in fancy mathematical terms but your guess is as good as the next guy’s. What a waste of space on this site. Get a grip.
Steve Adams
“This is the biggest bunch of crap I have ever read!”
One sentence later…
“I didn’t even read 95% of it!”
I dare say, this could be the greatest comment in the history of MLBTR.
southpaw2153
I didn’t read the entire article because the premise of predicting player performance and injury using math is laughable. The author even stated that only 5% of 10,000 professional pitchers needed UCL repair in the past 5 years. Not exactly a pct that screams, ” epidemic”.
If you belief tripe like this is going to ever drop the percentage of arm injuries to zero, you’re as sad as this article. Just because sabermetrics/mathematical analysis has crept into the game – unfortunately- doesn’t mean it is valid.
mrnatewalter
Arrogant, childish, and rude.
It’s one thing to read an article and disagree with it’s premise. It’s another to admit you haven’t read it, call it crap, and write off the premise altogether because you think you’re always right.
And if it’s crap and you can’t believe the premise, hit the back button on your internet and move along. No need to be rude.
southpaw2153
The human elbow/shoulder is not designed to throw thousands of pitches at max, or close to max effort, for years on end without suffering wear and tear and/or injuries. Any one that has ever pitched competitively knows that.
I never had any real problems with my elbow until I started throwing the slider. Throwing the fastball and curve are relatively easy on the shoulder/elbow. It’s the stress of the slider and splitter that wreak havoc on the slider. Just my opinion.
Anecdotally, I have noticed a lot of pitchers that throw hard sliders and splitters damaging their UCL. From my own experience, I can see why. No one can ever be sure of having the ” proper mechanics” to avoid injury. If I recall, most scouts raved about the ” perfect ” mechanics of Mark Prior and Steve Avery and those two were affected by arm injuries that shortened their careers. You just never know.
hstisgod
*insert Morgan Freeman, ‘he’s right you know’, meme*
hstisgod
Wow, just ground-breaking stuff. Truly impressed with this…regardless of it’s eventual accuracy, takes real hard work and courage to publish this.
houseoflords44
RA Dickey doesn’t have an UCL. Therefore, he can’t tear it
thecoffinnail
Having torn my UCL completely back in my playing days I would have to say that I think you missed on a couple of variables. I strongly believe I tore mine during routine warm ups the day after a game I pitched in. In that game my fastball didn’t seem to have much sink to it and it was getting hit hard. So, I wound up throwing twice as many sliders as I normally did. I firmly believe that using incorrect wrist action while throwing breaking pitches has a serious effect on the UCL. Your article was a great read and should be required reading for all hard throwing high school players. More information like this should be made available to the young players so they can work on getting their mechanics set to help avoid TJS when they get into college or pro ball.
RobM
Is there a point in a pitcher’s career after he reaches a certain age and has thrown a certain number of innings that he’s much less likely to ever have TJS, meaning the risk drops to near zero no mater how many innings he’s thrown? Just as some elbows are going to blow out early, others may never blow out due to genetics.
Roasted DNA
The fact that you smoked an I7 chip is impressive enough. In looking at Drew Smyly, I’m still wondering how you translate shoulder issues into elbow surgery? I briefly read the part about release points, hard pitches etc. but how a specific injury affects a certain part of the body based on his history? Plus with hard pitches, Smyly compared to the rest of the league is a soft tosser when you compare fastball speed. Wasn’t there some data prepared before that showed as pitchers have progressed and more and more pitchers can chuck the ball past 95 MPH that more arm injuries travel with it?
I applaud your work. I think if the majority fans realized how much data baseball teams are now generating to develop just the slightest advantage while all the while managing it back to $$$ – jaws would drop. This explosion of data has changed this game not only from a player perspective but from a FO perspective.
Thanks to all for the work put into this!
flonnaise
Been working on this for seven months, huh?
eilexx
The uptick in UCL injuries likely has to do with pitchers nowadays throwing everything at max effort. It doesn’t matter if it’s the first inning, the 7th inning, a fastball, a curveball or anywhere in between, pitchers are taught to throw everything as hard as they can. Pitchers of the past actually PITCHED, and left something in the tank for when they needed to “reach back” for a little extra. Today there is no extra…there is max effort, 100% of the time, which puts that strain on an elbow/arm, so pretty much every pitcher is at equal risk. Matt Harvey came up with “perfect mechanics” and that worked out great.
timyanks
one solution would be just go ahead and put all pitchers under the knife at a given age and do the surgery and give them a bionic arm insert.
nafro
It should be noted that I am relatively certain that R.A. Dickey does not have a UCL to replace. It was discovered earlier in his career that he actually didn’t have one.
nafro
I should have read all the comments first. I guess that was already noted.
scottaz
Purely speculative at this point, but just announced Carte Capps going for an MRI and the Marlins already in the market for relievers. Carter Capps is in the Top 10 of this list.
jchiaratti
Aaaand, down goes Capps… TJ surgery confirmed for CC… Curious to see how many more of the top 10 fall victim this season (while quietly hoping it’s zero… ESPECIALLY hoping #3 on the list can stay healthy)
hstisgod
From a fantasy perspective, Hahn and Holland scare me the most
hufnagel
In the very first sentence, you mention the number 112 surgeries. At what level??? Pros only? Including little league? Please specify as it sets up the whole article, like an attention-getter should.
hstisgod
I was gonna just laugh this off, but wow…lol, this guy^
While this is a very in-depth and risky piece you can only go so far. Lest we forget, Its a website that while often wanders off to affiliated MLB topics, its still about MAJOR LEAGUE BASEBALL.. you really expect them to crunch the numbers of every baseball player in the nation, young and old? Should we include my four-year-old tee-baller? Their research has boundaries for a reason.
Tired of you internet trolls (and yeah I’m looking at you) who are jealous of someone else’s courage and innovation, too afraid to give credit where credit is due. This has been a serious hot topic and few pundits have even has the audacity to weigh in, so instead of spitting on it with some silly expectation, be realistic and find another hobby other than spreading negativity. Or split hairs for the rest of your life and keep up the envy, green is your color.
hufnagel
Hi, I’m new to this site number one, and so I really have NO idea what exactly gets posted here. Especially with a name like “Trade Rumors.” Does that mean only trade rumors? I guess not. So thanks for setting me straight on that (I guess). I’m not even sure how your reply really relates to my question. What about it is negative? Because I want more info? And how do I know whether it’s MLB only, don’t you think 112 in one year is an awfully high number? I mean like not remotely believable? Hopefully the author will clarify this point. BTW, just because I have a question doesn’t mean I am not appreciative of the article.—And I am not a troll. I don’t even live under a bridge. You might want to look at your own negative tone too.
piratewolf
I wonder if average % of top FB velocity (or differential between average FB velo and top FB velo) would have an impact. That is, do guys who consistently throw closer to the top of their FB velo range have a higher rate of TJS?
For example,
If Pitcher A has a FB that tops out at 98 mph and his average FB sits at 96.5 mph, is he more likely to have TJS than Pitcher B who also has a FB that tops out at 98 mph, but whose average FB sits at 95.5 mph?