It's like training for a marathon. You need to build stamina incrementally. The unofficial industry standard is that no young pitcher should throw more than 30 more innings than he did the previous season. It's a general rule of thumb, and one I've been tracking for about a decade. When teams violate the incremental safeguard, it's amazing how often they pay for it.
Here's the way I track it: Find major league pitchers 25-and-under who broke the 30-inning rule.
In 2005 and '06 I found 17 pitchers I defined as at-risk of the YAE. None made it through the next year without an injury or a higher ERA. Ten of them broke down, the most seriously hurt being Francisco Liriano, Gustavo Chacin, Adam Loewen, Scott Mathieson and Anibel Sanchez. Eleven of them had worse ERAs, by an average of about a run and a half. Remember, it's a general rule; there are exceptions, the superlative Justin Verlander being one.
Verducci takes the three Yankee kids as a test case and lays out the max IP ceilings for each, based upon his parameters above:
- Kennedy: 195 innings
- Hughes: 176 innings
- Chamberlain: 149 innings
Verducci's Top Seven "at risk" for YAE are below, listed in order, Player Name, Age, Increase in IP over 2006 IP:
- Ian Kennedy, Yankees, 23 (+61 IP) "One caveat: Kennedy's jump is not as alarming as first blush indicates. The Yankees did give him an extra 30 1/3 "unofficial" innings of winter ball in 2006 (see Carmona below); not your high-stress big league innings, but still good incremental training. If you count that work, his jump of 30 2/3 innings barely pushes him into the danger zone."
- Fausto Carmona, Indians, 23 (+56.1)
- Ubaldo Jimenez, Rockies, 24 (+41 2/3)
- Tom Gorzelanny, Pirates, 25 (+40 1/3) "While Gorzelanny was passing his career high in innings, the Pirates let him throw 105, 118, 107, 107 and 117 pitches in meaningless consecutive September starts. Why?"
- Dustin McGowan, Blue Jays, 25 (+38 2/3)
- Chad Gaudin, Athletics, 24 (+36)
- Yovani Gallardo, Brewers, 21 (+33)
Lastly, from Verducci:
Keep in mind what the Boston Red Sox did with Clay Buchholz last year. The kid, who turned 23 in August, threw a no-hitter in his second big league start. As the Red Sox scrambled down the stretch to fortify their bullpen (Eric Gagne, anybody?), Buchholz looked like a perfect option in front of Jonathan Papelbon. But the Red Sox resisted pushing Buchholz and shut him down in September and the postseason. His innings increase in 2007? They shut him down right at +29, just under the YAE threshold. Now he's healthy and on track to throw no more than 78
innings this year.