The Dodgers have signed Clayton Kershaw to a seven-year, $215 million deal. (Check out this amazingly prescient analysis of the Dodgers/Kershaw negotiations from yesterday morning by Dave Cameron of Fangraphs, a few hours before the deal was inked.) Kershaw is 25, so this contract will run until he's 32, though he has the option to opt out and become a free agent after five years.
Kershaw is, without a doubt, the best young pitcher in the game today. Still, seven years seems like a long time for a pitcher. Is it, though, for someone of Kershaw's stature? To test this, I looked at the best hitters and pitchers, 25 or under. I based "best" for hitters on OPS, adjusted for home park, over the prior three years, minimum 300 games played. The best pitchers were those with the best ERA, adjusted for home park, over the prior three years, minimum 300 innings pitched. The five best young hitters, 2011-13, are Mike Trout, Andrew McCutchen, Giancarlo Stanton, Paul Goldschmidt, and Brandon Belt. The five best young pitchers are Kershaw, Chris Sale, Stephen Strasburg, Jeremy Hellickson, and Jhoulys Chacin.
I looked at the five best young pitchers and hitters for 2001-2003, 1991-1993, 1981-1983, 1971-1973, and 1961-1963. That gave me a list of 25 hitters and 25 pitchers. Then I checked how many of them were still above-average regulars seven years later, as the Dodgers are expecting Kershaw to be. For example, in 2001-2003, the top five young hitters were Albert Pujols, Pat Burrell, Eric Chavez, Adam Dunn, and Troy Glaus. Pujols and Dunn were still above-average regulars seven years later in 2010. Among the top five young pitchers, Roy Halladay and Johan Santana were still going strong, while Mark Prior, Roy Oswalt, and Barry Zito weren't.
Of the group of 25 young hitters, 16 were still above-average regulars seven years later. That's 64%. Among the pitchers, 10 of 25 were above-average regulars seven years later. That's just 40%. The best young group was the 1991-1993 hitters: Frank Thomas, Ken Griffey, John Olerud, Juan Gonzalez, Jeff Bagwell. All of them were still productive seven years later. The worst group was the 1961-1963 pitchers: Bill Monbouquette, Jim O'Toole, Don Drysdale, Jim Bouton, and Steve Barber. Bouton and Barber were the only two still pitching seven years later, neither regularly nor well.
A lot of people are saying that the Kershaw contract makes sense. He's an amazing talent, and baseball's awash with money, especially his employer. Keep in mind, though, that most outstanding young pitchers aren't effective regulars seven years later. That's not to say Kershaw can't stay great. But if he succeeds, he'll be defying the odds against him.