Mariano Rivera’s Projections and the Value of the Closer

It’s not exactly surprising that of all the pitchers that the fans have projected so far, Mariano Rivera is the leader in saves, ERA, WHIP, and K/BB. After all, Mo has been hands down the greatest reliever of his era, if not all time, and has shown no indication of slowing down. Here’s what his fan projection line looks like (as of 2:40 AM ET on Friday)

77 IP, 4-4, 2.38 ERA, 41 SV, 9.23 K/9, 1.52 BB/9, 6.08 K/BB, 0.70 HR/9, 2.61 FIP

Pretty fantastic numbers. It’s hard to imagine a reliever with a better line, except for maybe Mariano himself. Of course, this brings up one of the more interesting questions regarding value in baseball, and that’s the value of the closer. Right now, this line by Rivera is projected to be worth 2.4 WAR. This is easily the best of the three relief pitchers so far projected, besting David Aardsma‘s 1.3 WAR and Takashi Saito’s 0.5 WAR. If the crowd is truly wise, it will remain the highest. So then is 2.4 WAR truly as good as a reliever can be?

Probably not. That’s mostly because this measurement doesn’t account for leverage index. This certainly can be done, and it is done in some places. Sean Smith’s WAR database at www.baseballprojection.com uses the mean of 1.0 and the pitcher’s actual leverage index. As Smith explains in his stat definitions, this is because of the effects of chaining. That is, the actual replacement for the closer’s innings isn’t a replacement level pitcher. The replacement is actually the setup man, who, on most teams, is nowhere near replacement level. As such, giving the closer full credit for the leverage of his innings isn’t a true representation of his value.

Even if we did, though, we still wouldn’t see any closer come near the value of the top-flight starters. Tim Lincecum right now is projected for an 8.0 win season by the fans (which is slightly ridiculous, but that’s another matter), and Mariano Rivera would be projected for a 4.8 win season with a LI of 2.0, slightly high for a closer. Similarly, Rivera comes nowhere near our top position players, Chase Utley (8.2 WAR) and Albert Pujols (8.0 WAR). The key here is that Rivera simply will not take part in enough events over the course of the season to impact a game nearly as much as the Utleys and the Greinkes, or the Pujolses and the Lincecums. His events may be better and they may be more important, but sometimes quantity does trump quality.

Mariano Rivera’s true value probably falls somewhere between the 2.4 WAR the base numbers give and the 4.8 WAR his fully leveraged numbers give. Remember that this isn’t only the best reliever out there, but a guy that is by a wide margin the best reliever. This is why many analysts, such as myself, are constantly wary of big money signings or marquee trades involving closers.