Predicting Tommy John surgeries for the Cubs

Tommy John

Today at mlbtraderumors.com, Bradley Woodrum released a piece that is quite extraordinary with how much time and effort he spent on predicting the likelihood it is for each pitcher’s ulnar collateral ligament (UCL) to shred apart thus resulting in Tommy John surgery. That great look can be found here.

In the piece he gives great detail about the factors and variables he took into consideration, along with a few he thought about but chose against. Along with providing us a top-10 of “most likely” and “least likely” candidates, here is a complete interactive list of each team’s players.

I’m going to take a look at the Cubs pitchers’ “ratings,” as I find a couple of the results to be interesting for certain pitchers on the North Side.

With the average set at zero percent, there were seven Cubs pitchers who exceeded that mark according to Bradley’s research. Just in case you didn’t click the link to the piece above (I can’t emphasize how much you should do that, so here it is again), the factors he took into consideration are broken down like this: RHP/LHP, standard deviation of release point, days lost to arm/shoulder injury, whether or not there was previous Tommy John surgery, the amount of hard pitches, and age.

When I first saw the article, Jake Arrieta was the first name that came to mind as I thought he would have the most likely chance to need Tommy John after throwing a ton more innings and pitches than he ever has. That isn’t the case, however. He comes in at six for the Cubs at a two percent chance to need the surgery as his age (29) and hard pitches (1,764) put him at a prediction of .50 (scale from 0 to 7 for above average; negatives for unlikely). Arrieta threw only 50.7% hard pitches (defined by fourseamers, twoseamers, and sinkers) according to Fan Graphs.

Bradley states that is more likely (especially nowadays) for a pitcher to need Tommy John at a younger age, but it still surprised me to see Kyle Hendricks at 15% above the average (still only at two percent as the risk factor). Hendricks is only 25 so his likelihood risk factor rises above someone like Arrieta. Hendricks threw more hard pitches than Arrieta (1,793). His likelihood is still low (as most Cubs pitchers are), and Bradley has his prediction at .56.

Despite his age (decreases need for Tommy John), John Lackey’s name was found at the prediction line of .56 being at two percent risk. Lackey’s higher volume of hard pitches (2,104) and already having Tommy John probably pushed him to above the average line for likelihood. With him being 36 and how he’s redefined himself as a pitcher the last couple seasons (and after last year), I’m not really concerned about him as and probably would be more scared of Pedro Strop needing the surgery (sits at one percent risk rate, and -32% below the average).

At a 58.5% fastball rate, Hector Rondon (only 27) is the second most-likely Cubs candidate, according to Bradley. The probable Cubs closer sits at 56% above the average (still only two percent risk rate). What’s surprising here for me is that he’s already been under the knife for Tommy John, but because of his still-young age he isn’t seen as a major threat to repeat. It’s always concerning to see your team’s pitchers on this sort of list (duh), but I think it bumps it up a small knotch when it’s your team’s closer who’s been worth 3.2 WAR according to Fan Graphs over the past two seasons.

The pitcher rated most-likely for the Cubs is Justin Grimm. His 56.2% fastball rate adds to him only being 26 with no Tommy John history, but missed 31 days in 2015 due to what’s classified as an arm/shoulder injury in this research. His risk rate is still at a mere three percent, and 92 Risk+ (nearly twice as much risk as the average pitcher on this list).

Other pitchers above average for likelihood is Brandom Gomes and Adam Warren. Clayton Richard is last on the list for the Cubs at 107% below league average, while Jon Lester is at 87%.

Once again, go check out the full article and use the filter to look at other teams/compare teams. It’s pretty neat.

UPDATE: Bradley mentioned some stats he came across in his research.

And emotion goes with baseball more than ever.