Young Pitcher Symposium: Mark Prior
Everyone wants to know what the future holds for Mark Prior. Hell, I don't know any more than you do. He's certainly proven that he is an excellent major league pitcher, when healthy. Alas, he hasn't been healthy very often lately, and his "sore rotator cuff" problems this spring are frightening for legions of Cubs fans, fantasy owners, the Chicago front office, and no doubt Prior himself. Is this all Dusty Baker's fault, or was Prior destined for injury all along? We don't know the answer to that, either, although we can certainly point out some relevant facts.
Prior was considered a top prospect from his high school days, earning a supplemental first-round pick in 1998 by the Yankees, but choosing to attend college at USC instead. He was a no-brainer as a prospect, a certain Grade A guy with superb stuff and excellent command. It should be noted that he was a California high school pitcher and a California college pitcher: he has more mileage on his arm than a lot of pitchers his age. "Flawless" mechanics or not, his health problems have not been out-of-bounds from what you'd expect given his background. Add Dusty Baker to the mix, and Prior's arm problems are far from unexpected.
What does the future hold? Here is a list of eight comparable pitchers, derived from PECOTA, Sim Score, and my own research.
Active comps include Roger Clemens, Kerry Wood, and Jon Smoltz. Tom Seaver and Fergie Jenkins also show up as PECOTA comps, though neither had the same kind of injury problems that Prior has had at the same stage of their careers.
Some of the names may not be familiar to younger readers, but all of these guys were very good pitchers, some of them terrific at times.
Don Wilson: 1748 innings over 9 seasons, career over at age 29. Career record 104-92, ERA+109. A comparison with Prior may be misleading, since Wilson's career ended because he died.
Erik Hanson: 1555 innings over 11 seasons, career over at age 33. Career record 89-84, ERA+106. A very strong pitcher when healthy, but he had injury problems for several years and was no longer effective after age 30.
Stan Williams: 1764 innings over 14 seasons, career over at 35. Career record 109-94, ERA+108. Very effective early in his career, overpowering at times, but was injured and on the shelf most of the time from age 26 through 30.
Scott Sanderson: 2562 innings over 19 seasons, career over at 39. Career record 163-143, ERA+102.. Threw hard early in his career, but injuries sapped his velocity, forcing him to rely on movement and control. Frequently injured from age 26 through 32, though usually pitched well when not hurt.
Bob Welch: 3092 innings over 17 seasons, career over at 37. Career record 211-146, ERA+ 106. Injuries and personal problems cost him time in his early 20s, but he had a solid run of pitching in his early 30s.
Steve Busby: 1061 innings over 8 seasons, career over at 30. Career record 70-54, ERA+ 105. Brilliant pitcher in his early 20s, but burned his arm out quickly.
Mario Soto: 1730 innings over 12 seasons, career over at 32. Career record 100-92, ERA+108. One of the best pitchers in the game for three seasons, 1982 through 1985, but his arm blew out.
Ramon Martinez: 1896 innings over 14 seasons, career over at 33. Career record 135-88, ERA+ 105.Outstanding early, hurt his arm at age 24 and was never really the same afterward, though he held on as an adequate starter for some time.
Now, this isn't exactly scientific or heavily sabermetric, but taking those guys and doing a simple averaging out of the results, gives us this:
Mark Prior Possible Career Profile: A 13 year career, 1926 innings pitched, career over at age 34, 123-99 record, ERA+ of 106.
That may seem like a disappointment considering the Tom Seaver fantasies which swirl around Prior, but if you think about it, the numbers above are a completely reasonable projection of what we can expect Prior's career to look like if he continues to have arm trouble. . .a regression towards the mean in the ERA+ and winning percentage departments, but still an above-average pitcher who will have a good career.