There has been a growing public perception that with today’s skilled surgeons and rehabilitation experts, undergoing Tommy John surgery is more of a one-year layoff in a major league pitcher’s career than a procedure that puts his career in jeopardy. A corollary of this belief is that trying the rest-and-rehab route on a partially damaged ulnar collateral ligament is not worth the effort, as it ends up only delaying the inevitable Tommy John surgery, which while costly is a nearly automatic method of restoring a pitcher’s health so he can pitch at the major league level again.

A number of studies both in the academic arena and the public research space have arrived at similar success rates for Tommy John surgeries. The American Journal of Sports Medicine has published a number of such studies. One reported a return to major league baseball rate of 83 percent, one reported a return rate of 80 percent, and a third reported a return rate of 79 percent. My own Tommy John surgery database calculates a running total of return rates to MLB, for which the current rate for all surgeries performed before the end of 2013 is 78 percent. So right away we can see that full recovery from the surgery is not so automatic, that only four of five pitchers who undergo the surgery after making the majors return to pitch there again.

The definition of “success” in each of those four studies is a return to pitch in a single major league game. This is certainly an understandable and worthwhile metric to measure. It implies that a number of rehabilitation milestones were reached and that his organization feels the pitcher is ready for big league action.

I would submit that a more relevant question would be how often pitchers return and contribute in a meaningful way. After all, a pitcher returning to make an appearance or two over a mere handful of innings, then falling out of the major league level for whatever reason, can hardly be considered a successful outcome for the player or his organization.

Even with this in mind, there are a number of ways one could define a “meaningful contribution.” As one example, it would be possible to compare each pitcher’s performance to what it was before the injury. For the purposes of this study, though, I will look solely at the quantity of game action a player participates in following the return from the surgery. Merely appearing in major league games and accumulating innings pitched implies that a pitcher is both healthy enough to perform, and performing at a level deemed high enough for the organization to allow him to log major league innings. This feels like a more robust method of analyzing what can be expected from pitchers returning from Tommy John surgery.

Below are two graphs that attempt to convey the results of looking at recovery in this manner. The vertical axis in each graph signifies the percentage of major league pitchers who have returned from Tommy John surgery, while the horizontal axis shows the number of post-surgery game appearances in the first graph and the number of post-surgery innings pitched in the second graph. The set of pitchers has been broken down by era in which the Tommy John surgery took place: 1974-1999, 2000-2009 or 2010-2012.

The data for 1974-1999 are complete, as all 57 major league pitchers who underwent the surgery in that time frame have retired. There are still 21 of the 138 major league pitchers who underwent the surgery between 2000 and 2009 still active. For this reason, this era is shown with upper and lower bounds on the return rates, which depends on the future participation level of these active pitchers. The final, most recent, era consists of 62 pitchers, of whom 42 are still active. Once again, the return rates are shown as a range of potential outcomes, which is relatively massive given the recency of the surgeries and the number of pitchers involved.

Several interesting observations can be made from the graphs. To start, it is apparent that overall more pitchers returned to pitch at the major league level for longer periods of time when they had their surgery last century than in the 2000s. This is represented by the green band being lower than the red line in both graphs. Consider the median number of post-surgery appearances and innings pitched based on the era:

Post Tommy John Surgery Medians by Surgery Era

Surgery Era Appearances (G) Innings Pitched (IP) 1974-1999 89 167 2000-2009 58-61 94-100 2010-2012* 29 47

*includes games until end of 2014 season

The fact that the innings pitched totals look somewhat more disparate than the games played totals is at least partly a result of the increased use of pitcher specialization in more modern baseball. Pitchers are typically not asked to face as many hitters in a given appearance as they were before the turn of the century.

The range of potential outcomes for pitchers who have undergone Tommy John surgery since 2010 is still too wide to compare. What is possible to see from the graphs is that it will take the best case scenario from this point forward for this most recent range of years to live up to the 1974-1999 era as far as having pitchers return for at least a single major league appearance.

I find these numbers enlightening, but also quite staggering: In the most recent complete decade (2000-2009), the median result for a major league pitcher returning from Tommy John surgery is appearing in about 60 games or logging about 100 innings pitched over the rest of his major league career. That’s about the number of appearances we would expect from a typical healthy reliever in one season. It’s roughly the number of innings pitched a healthy starting pitcher would amass in half a season. That’s not the sort of post-surgery career one might envision.

To answer the question I am asking, it is important to include pitchers who did not return to the majors at all. But if you’re curious about the typical post-surgery career for just those pitchers who do get back to major league baseball, the median games played was 102 and the median innings pitched was 167 for all major league pitchers who underwent the surgery between 1974 and 2009. Even these totals hardly make for exciting post-surgery careers.

While the numbers are far from complete, it is also worthwhile understanding that of all major league pitchers who had Tommy John surgery in the past five years — who have had one to four seasons to theoretically recover (2010-2013) plus one to four seasons to theoretically contribute (2011-2014), the median contribution has been 29 appearances and 47 innings pitched. So: that mental math you do when it’s announced that a pitcher on your favorite team is having Tommy John surgery, when you picture them contributing at the same level as you’re used to one calendar year from then? It’s not as reliable as you may believe.

It would stand to reason that a 23-year-old pitcher a year or two into his major league career may have a different typical recovery profile than a 35-year-old journeyman reliever. While seeing the overall numbers is helpful, it also seems pertinent to break down the return rate information by age of the pitcher at the time of surgery.

For these two graphs, I used only the 195 Tommy John surgeries performed on major league pitchers between 1974 and 2009, since the data from this period are basically known at this point. The images show the expected relationship between age and post-surgery game participation, with pitchers typically appearing in fewer games and accumulating fewer innings pitched the older they are at the time of surgery.

Let’s also look at the median results by age grouping:

Post Tommy John Surgery Medians by Age Groups, 1974-2009 surgeries

Age at Tommy John surgery Appearances (G) Innings Pitched (IP) 16-23 93 221 24-27 70 137 28-31 74 130 32-50 29 46

Again, we see that younger pitches contribute for longer, but these are still modest figures.

One final way we can break down return rates is by the number of months it took for the pitcher to return to major league action fom the time of his Tommy John surgery. This topic was of particular interest in the case of Matt Harvey; it was reported that Mets GM Sandy Anderson believed 11 months was an appropriate recovery time from Tommy John surgery, while Scott Boras trumpeted doctors’ recommendation of 14-16 months.

The following graphs use the same sample of 195 surgeries from 1974-1999, although they select only those pitchers who did return to major league action and for whom their surgery date is known specifically enough to calculate their return time accurately. This leaves 141 pitchers in the sample. Note that the numbers and percentages will be higher now, since by definition we are excluding those pitchers who never returned to the majors after their surgery.

Below is one final table showing the median appearances and innings pitched by return time range. I have increased the resolution here as much as possible and cited the number of pitchers included in each grouping.

Post Tommy John Surgery Medians by Return Time to Majors, 1974-2009 surgeries

Return, Months after surgery Appearances (G) Innings Pitched (IP) # of Pitchers 1-11 87 106 18 12 124 155 22 13 128 179 19 14-16 129 239 20 17-20 102 254 21 21-24 122 195 18 25-100 49 104 23

The data here certainly appear to favor Boras’ more conservative 14-16 month time line over Alderson’s 11-month schedule. In both appearances and innings pitched metrics, return times of fewer than 12 months as well as times of over two years both have proven to be far less successful. Perhaps this suggests there is such a thing as returning too soon. On the long end, slower returns mean wasted time and may also indicate rehabilitation issues that might affect performance.

When assessing by the number of games entered post-surgery, the 12-16 month recovery window has shown to produce the best results. By considering post-surgery innings pitched, history has shown that pitchers returning after a slightly longer span, in the 14-20 month range, have out-pitched those returning slightly more quickly or further removed from the procedure.

When we think about pitchers who have recovered from Tommy John surgery, our minds tend to lock onto the successful ones. Tommy John himself. A.J. Burnett. Adam Wainwright. Jordan Zimmermann.

What is critical to understand is that one out of every five major pitchers who undergoes the operation never throws another pitch at that level. These are less familiar names, given their career-ending injuries. Ambiorix Burgos. Anthony Reyes. Macay McBride. Bill Simas.

The most recent data suggest that one out of two major league pitchers who has Tommy John surgery will throw fewer than 100 innings the rest of his big league career. Bill Bray. B.J. Ryan. Taylor Buchholz. Victor Zambrano.