There has been an interesting discussion in the comments about the value of Mariano Rivera to the Yankees. On one level, I don’t disagree with the arguments of the skeptics. While has value is almost certainly understated by WAR — which, if I understand correctly, doesn’t take leverage into account, hence understating the value of a close, I certainly agree that in the regular season Rivera has obviously not been nearly as valuable as Jeter, Posada, Williams, A-Rod, et al. Another way of looking at the question is Tom Tango‘s study in this year’s Hardball Times book, which assesses Rivera’s value as only about 2 wins a year more than the rest of the Yankee bullpen, which can’t be considered to be significantly more valuable than an ordinary closer and is probably less. Having said that, I think this underestimates Rivera’s value to the Yankees for two reasons:
- As I assume is widely understood, what makes Rivera by far the best closer ever is not exceptional single-season performances but his remarkable consistency. His peak value is no higher than the man he replaced, John Wetteland — an excellent but obviously not Hall of Fame caliber closer. What makes Rivera extremely valuable to the Yankees is that he’s healthy and pitches about as well as any closer in baseball every year (2002 aside.) Brad Lidge, in his best years, is about as good as Rivera — except that his ERA+ in a given year ranges from 225 to 60. (Yeah, they made it to the World Series in his worst year anyway, but won only 93 games with an outstanding offense and good rotation; in a good division it would have cost them.) Rivera may only be a game or two better than an ordinary closer, but he gives the Yankees that edge every year. They haven’t had to worry about a closer blowing up on them (a la Keith Foulke in 2005), costing them several games. That’s real value, more than his value in any given season reflects.
- And, obviously, when assessing his value one has to take into account his postseason record — 139 2/3 mostly high-leverage innings with a 0.71 ERA and 109/21 K/W. I don’t think there is any serious question that he’s by far the most valuable postseason performer ever, surely relevant when assessing his overall value. The Yankees don’t win five World Championships with a Joe Nathan or Trevor Hoffman doing an Incredible Shrinking Closer routine in the playoffs.