Joe Posnanski of the Kansas City Star takes some interesting date from the Bill James Handbook and concludes that Mariano Rivera was the best closer in baseball in 2008.

We've all known that Mariano had an incredible season (a career best 0.67 WHIP, a 1.40 ERA that missed his career best by 0.02 points, 77K against a career low 6BB(!!!) in 70.2IP, not to mention pitching 70+ innings for the 6th straight season and 8th out of 9).  Mo finished 5th in Cy Young voting; it's the fifth time he's received votes (fun fact: Mo has appeared on the Cy ballot 5 times and the MVP ballot 8 times).

Bill James divides saves into three categories: easy saves, a regular save (1 run lead in a clean 9th), and tough saves.  Only Mo had as many as 5 tough saves last season, and he recorded each of them.

Never content to let statistical brilliance suffice when analytic observations can be added, Poz goes on to argue that Rivera has been even more valuable than his numbers because a the negative impact of an ineffective closer:

definitely seems to have an effect on the general atmosphere, the energy level, the manager’s enthusiasm, the talk radio tenor and so on. These things are multiplied in New York. And basically, in the case of Mariano, one guy has more or less eliminated that negativity from the equation.

An interesting theory to say the least, and an angle I think that Brian Cashman was forced to consider when he gave Mariano that $45M/3Y deal.  You can claim Yankee fans are different than other fans in a dozen ways like expectations, energy, expertise (sorry, I'm a sucker for alliteration).  But like every other fan base, we love our home grown players best.  And that makes it all the sweeter when the world sees that player is the best in the game.