The Captain's Blog

During last night’s broadcast, John Flaherty, Paul O’Neill and Michael Kay revisited the often debated question of who has been the Yankees most valuable player during their recent extended run of success: Derek Jeter or Mariano Rivera?  This topic has often been broached on YES broadcasts, including most recently during Jeter’s pursuit of the all-time team hit record, but last night’s mention inspired Joe Posnanski to delve into the issue head long.

Posnanski’s perspective is a worthy one because he not only isn’t a Yankee fan or close follower of the team (in fact, he admittedly dislikes the Bronx Bombers), but also has an eclectic circle of contacts from which to draw reference. So, not surprisingly, he sums up the debate as being one without a correct position, or has he evocatively put it, “a debate of head versus heart or Ginger versus Mary Ann”.

Within that framework, there are many reasonable arguments supporting either candidate. There is no “case closed”. Having said that, Posnanski’s line of reasoning seems to imply that the case for Mariano can only be made from the heart, and that really isn’t true either.

For starters, Posnanski credits Rivera with only 35.8 wins above replacement to Jeter’s 70.6, but according to Baseball-Reference.com, the gap currently sits at 52.3 to 70.3, respectively. So, off the bat, Jeter’s statistical advantage has been narrowed.

Of course, comparing Jeter to Rivera directly ignores the relative value of each player to the other leading candidates at their respective positions. Although both men lead their positions in WAR since 1996, Rivera’s 150% premium over the average total of the remaining members of the top-10 trumps Jeter’s 97% advantage. What’s more, it should also be pointed out had Alex Rodriguez not moved to 3B when he joined the Yankees, he, and not Jeter, would be the clear cut leader at the position.

WAR Leaders by Respective Position, 1996 to Present

*WAR for shortstops derived by summing individual seasons in which position was played at least 80% of the time. WAR for relievers determined by taking pitchers who served as a reliever in at least 80% of games during defined period.
Source: Baseball-Reference.com

Now that statistical picture has been muddied a little, it’s time to introduce another variable left out of Posnanski’s equation…the post season. Unfortunately, WAR is not a statistic that is calculated for the post season (at least not to my knowledge), so comparing a pitcher and a hitter becomes tricky. Still, it is worth a shot.

Post Season Statistics, 2005 to Present

Source: Baseball-Reference.com

The first thing that jumps out about Mariano Rivera’s post season record is that come October he pretty much transforms into an everyday player. In fact, Rivera’s 501 batters faced aren’t that far off from Jeter’s 637 plate appearances, at least not in terms of a reliever/position player comparison. Relative playing time aside, Rivera’s post season statistics absolutely jump off the page. His ERA of 0.74 and WHIP of 0.773 speak for themselves, but the most astounding figure is his 80% out conversion rate (400 outs in 501 batters faced). Meanwhile, Jeter’s OPS of .863 is certainly impressive, but far from the jaw dropping level of performance put forth by Rivera. Does this difference overcome the regular season WAR advantage enjoyed by Jeter? Who knows, but you’d have to think it narrows the gap at least somewhat.

As great as Jeter has been, the case for Mariano Rivera being the most valuable Yankee over the recent dynastic period seems stronger. That’s not to say that Jeter isn’t in the running, but unlike Posnanski, I would suggest his argument is bolstered less by the brain and more by the heart. Regardless of what side one chooses, however, what is abundantly clear is the New York Yankees have been incredibly lucky to have both.