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Chris O'Leary's Pitcher
Injury Predictions

I have been evaluating pitchers and their pitching mechanics since 2006, starting with Mark Prior and Anthony Reyes. Over that time, I have developed and refined a Pitcher Injury Risk Rating Algorithm (PIRRA) to the point where I no longer make my detailed evaluations of current pitchers publicly available. For more information about of some -- but far from all -- of the inputs that go into PIRRA, see The Epidemic.

However, in the interest of demonstrating PIRRA's power, on this page are links to predictions I have made previously, some of which I made on my pitching mechanics analyses page and some of which I tweeted @thepainguy. I also mentioned many of these names in my 2014 pitcher injury podcast with Will Leitch. I also put together a list of vulnerable pitchers at the 2015 All-Star break.

I have used the few misses to continually update and improve PIRRA.

You'll note that in most cases I reference Tweets that can be found on and that are date-verified as a result.

Nailed It

If you're looking for the single best demonstration of my ability to see pitching injuries coming (in advance) it would have to be this thread. I express my concerns about both Matt Harvey and Jose Fernandez, Harvey a couple of days before his elbow injury and Fernandez a few years ahead of both his elbow AND shoulder problems.

The Tipping Point

The accuracy of these two predictions convinced me that my algorithm has progressed to the point where it's time to put it in production.

Jose Fernandez

My most recent successful set of predictions were about Jose Fernandez. I saw both his elbow injury and his shoulder injury coming a month in advance.

For more information about Jose Fernandez, I have put together a piece that discusses Jose Fernandez's pitching mechanics at length.

Henderson Alvarez

Another recent, and extremely accurate, prediction from 2015 is Henderson Alvarez.

Jarred Cosart

Although he isn't definitively dealing with a pitching-related injury, I believe Jarred Cosart's problems may be due to Thoracic Outlet Syndrome or something similar and are caused by his high elbows and resulting timing problem.

Prior Predictions

Some of my more prominent predictions -- predictions which generated significant press coverage -- are listed below.

Jaime Garcia

The bottom line on Jaime Garcia is that I don't think his elbow problems are a fluke. Like BJ Ryan, I think Jaime Garcia is headed for Tommy John surgery followed a couple of years later by shoulder problems.

Jaime Garcia Pitching Mechanics Analysis
July 21, 2008

Tommy Hanson

If I ran the zoo, I would shut Tommy Hanson down for 2011 and pray that he heals during the off-season. I would then convert him to a closer. His timing isn't going to allow him to stay healthy as a starter.
Tommy Hanson's Pitching Mechanics

Matt Harvey

Matt Harvey

Matt Harvey

Here's a picture of Matt Harvey that shows the timing problem that I am talking about and that concerns me. Given that his front foot is down, his pitching arm should be more vertical.

Matt Harvey Pitching Mechanics Analysis
May 13, 2013

NOTE: I first publicly expressed concerns about Matt Harvey's pitching mechanics on on May 9, 2013 on the Steve Czaban Show (Yahoo Sports Radio). My Matt Harvey comments start at 12:55. Matthew Giles of New York Magazine can confirm the validity of the above quote.

Ivan Nova

Named in my 2014 podcast with Will Leitch.

Ivan Nova

Ivan Nova

Mark Prior

I have written extensively about Mark Prior's pitching mechanics, what actually caused him to break down, and why I think Tom House continues to be part of the problem, not the solution.

Mark Prior

Mark Prior

This position isn't damaging in and of itself.
However, by coming to this position, Mark Prior is ensuring that his PAS arm will not be in the proper position at the moment his shoulders start to turn.
As with pitchers with other timing problems like rushing, because his arm is so late, he will dramatically increase the stress on both his elbow and shoulder.

Mark Prior's Pitching Mechanics

Anthony Reyes

Anthony Reyes

Anthony Reyes

I know a lot of people are extremely high on Anthony Reyes. However, I believe that I see a flaw in his mechanics that may very well make him the Cardinals' Mark Prior (and that's not a good thing). By that I mean a pitcher who shows tons of promise but ends up with continual injury problems.

My Concerns About Anthony Reyes
July 25, 2006

I am glad that my St. Louis Cardinals (finally) traded Anthony Reyes to the Cleveland Indians. I would be surprised if the Indians get significant value out of this trade due to Anthony Reyes' Inverted W and resulting timing problem.

Anthony Reyes Pitching Mechanics Analysis
August 11, 2008

B.J. Ryan

BJ Ryan

BJ Ryan

BJ Ryan is currently on the Disabled List due to Tommy John surgery. This is due to BJ Ryan's extremely poor pitching mechanics...BJ Ryan may have the worst arm action and timing I have ever seen, even worse than Chris Carpenter, Mark Prior, or Kerry Wood...The problem is that, like Chris Carpenter and Kerry Wood, BJ Ryan has a major Inverted L in his arm action. You can see BJ Ryan's Inverted L at Frame 21 of the clip above. This completely destroys his timing and is the root cause of his elbow problems. It will also set him up for Rotator Cuff and Labrum problems in a year or two.

BJ Ryan Pitching Mechanics Analysis
January 15, 2008

Johan Santana

There is no question that Johan Santana has been very successful to date. However, due to his borderline mechanics I question whether Johan Santana will be able to continue that level of success. I think Johan Santana could easily give the Mets the same heartache that Pedro Martinez and El Duque have.
Johan Santana's Pitching Mechanics

Stephen Strasburg

Stephen Strasburg

Stephen Strasburg

I have written extensively about Stephen Strasburg's pitching mechanics, both beforehand to express my concerns and afterwards to explain what happened.

More recent Predictions

Other prediction that I have made are below.

Walker Buehler

Dylan Bundy

AJ Burnett

Matt Cain

Named in my 2014 podcast with Will Leitch.

Matt Cain

Matt Cain

Carlos Carrasco

Tony Cingrani

Aaron Crow

Yu Darvish

Named in my 2014 podcast with Will Leitch.

Nathan Eovaldi

Buck Farmer

Mike Foltynewicz

Shane Greene

Hunter Harvey

Derek Holland

Greg Holland

Hisashi Iwakuma

The Inverted V is basically half of an Inverted W.

Josh Johnson

Also named in my 2014 podcast with Will Leitch.

Joe Kelly

Nathan Kirby

For more information, see my piece on the Power T and my analysis of Matt Harvey's pitching mechanics.

Tim Lincecum

I love Tim Lincecum's stride and lower body, but he has an Inverted L in his arm action that makes me nervous. I would argue that Tim Lincecum's Inverted L explains why his velocity has declined so dramatically.
Tim Lincecum Pitching Mechanics Analysis
Lincecum's still got a major timing problem that puts his shoulder and elbow at risk, although his velocity drop suggests that his shoulder may go first.
Baseball-Fever Thread

Lance Lynn

Justin Masterson

Charlie Morton

Jason Motte

Bud Norris

Jarrod Parker

I discuss Jarrod Parker's timing problem at length in my piece on Flat Arm Syndrome. In that piece, which was first published in May 2015, I stated that I didn't think anything was going to change if Parker didn't change anything.

Sadly, that turned out to be exactly the case.

Bobby Parnell

Wily Peralta

Chad Qualls

Hyun Jin Ryu

Aaron Sanchez

Matt Shoemaker

Craig Stammen

Major Inverted W. Hasn't broken down. Yet. It helps that he's a reliever.

Masahiro Tanaka

Named in my 2014 podcast with Will Leitch.

Jason Vargas

In June, people were saying Jason Vargas' forearm problems were no big deal; totally unrelated to any problem with his elbow. I disagreed. I thought his forearm problems were a sign of an impending UCL failure.

Jordan Walden

Yes, he's a reliever, and that will tend to reduce the risk. However, I don't believe that Jordan Walden's mechanics will allow him to last while being used in a regular set-up role. Instead, I think the only way he will last is being used as a stopper, not a regular set-up guy.


Jered Weaver

Zack Wheeler

Chase Whitley

Jordan Zimmermann

I predicted his Tommy John Surgery back in 2007. Now it looks like the Inverted L in his arm action may be starting to cause shoulder problems.

If you are interested in the topic of pitching injuries and the basis for the predictions I make, my interview with Will Leitch about pitching injuries is a good place to start.


I have made a large number of predictions, some of which haven't come true. In some cases, and particularly for relievers, my answer to why those predictions haven't come true is, "Just wait." However, in other cases, I have missed something and have had to update my algorithm as result.

Cliff Lee

I still like the majority of Cliff Lee's pitching mechanics.

That is because he lasted 13 years and, while he currently isn't playing, he hasn't needed Tommy John Surgery. And he plays for the Phillies.

So what's going on with his forearm?

As you may know, I am not a fan of the cue "Point the ball at second base" or "Show the ball to center field" in kids because I believe it significantly increases the risk of elbow problems.

Cliff Lee

I have video of Cliff Lee from his time in both Seattle and Philadelphia where his Premature Pronation isn't as prominent. However, the more high-quality images I accumulate, the more evidence I see that Cliff Lee has a problem with Premature Pronation. In my opinion, that is what's causing his forearm, and perhaps elbow, problems.

I used to think this was just an issue in kids, because I had never seen it (obviously) cause problems in adults. That's why I didn't take more seriously the (at the time) few pictures of Cliff Lee exhibiting Premature Premature pronation that I had. However, Cliff Lee's problems, while not necessarily severe, let me to take a much closer look at the problem of Premature Pronation and led to my correct predictions about Jose Fernandez.

I still think pitchers should copy Cliff Lee's pitching mechanics, but not that twist in the wrist of his pitching arm.

Michael Wacha

The simplest way to sum up what, in my opinion, is going on with Michael Wacha is this.

He's a different pitcher than he was in college.

As I discuss in detail in my piece on Michael Wacha's pitching mechanics, in college Michael Wacha was a low-90s guy who topped out at 94. As a pro, Michael Wacha is throwing significantly harder, sometimes with an average fastball velocity above 95 mph.

As with many pitchers (e.g. Noah Syndergaard, Matt Harvey, and Aaron Nola), as Michael Wacha's velocity goes up, so too does the load on his arm and his risk.

Max Scherzer and Clayton Kershaw

While they are hardly clean, they both employ the same trick to give their arms time to catch back up with their bodies. Max Scherzer is also apparently aware of my concerns about his arm action and actively works to make sure that his elbow lift doesn't cause him problems.

C.J. Wilson

C.J. Wilson's elbow jast gave in, so he wasn't a pure miss. However, he did take longer to break down than I thought he would. Why? Like Clayton Kershaw and Max Scherzer (and Sonny Gray), he employs a trick that helps his arm catch back up to his body. But obviously not completely.

Current Predictions

I have consolidated all of my current pitcher evaluations into one piece entitled Pitcher Picks and Pans.

About The Author

Chris O'Leary never played baseball beyond grade school due to a shoulder injury suffered due to poor pitching mechanics. As a result, he is focused on ensuring that what happened to him doesn't happen to anybody else. The Epidemic is one way he hopes to achieve that goal.

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