"If we were to break today, Nady would be my right fielder," Girardi said.

How can I measure my disbelief?

The latest research suggests that defense is even more important than we had previously believed.  At 43 runs below average, the Yankees were the second worst defensive team in the majors last season.

Giambi, Abreu, and Jeter all on the same field- it's a good thing the Royals were around to be even worse.

The Yanks have paid a lot of lip service to improving the defense- they learned the lesson of the Beltran non-sign, and this season they broke the bank for the premier offensive and defensive player available (Tex).

A team has 27 outs in which to score more runs than the opponent.  

UZR is a zone rating calculated by watching every game, measuring every hit ball (liner, fly ball, hard grounder, Baltimore chop, etc), and whether or not the fielder got to it.  There are flaws- since it's not a measure of distance covered, positioning is indistinguishable from skill, and (I believe) it gives no credit for knocking the ball down to hold the runner to a single.  But it's one of the best metrics publicly available.

UZR/150 is measured in runs saved over an average 150 games.  If a superior right fielder clocks in at 9.4 UZR in right field, it means he'll save you 9.4 runs more than the average fielder over 150 games.  And a -1.4 UZR means the opponent will score an extra 1.4 runs.

Those are, of course, the numbers for Swisher and Nady.  Oh, and in the last 3 years it's an even more profound split.  Swish looks about the same, but Nady actually posted his first positive season (2) since a 13.4 with the Padres in 2003 at age 24.  Take that one really good season out, and it gets ugly fast.

I use Pythag Standings a lot because its been shown to be a very effective predictor of final standings.  Last season, the Yanks expected to win 87 games, scoring 789 runs while allowing 727.  If we had saved 10 more runs (Swisher would save 10.8 runs over Nady), we could have expected 88 wins.  10 runs = 1 win.

I subscribe to the belief that the couple of wins separating playoff teams are decided by even narrower margins.  These marginal wins are the most valuable in the game because they decide who plays October baseball..

So how could you really choose the guy with the lesser defensive reputation, the lesser defensive stats, and the more inconsistent offensive history?

Can Nady's .256/.289/.488 line really look that much grittier and guttier than Swisher's .257/.400/.314?

Here's my stab at giving Joe G. the benefit of the doubt:

Since it usually takes a switch hitter like Swisher longer to find his stroke from both sides of the plate, Girardi could begin the season with Nady as the "regular" RF and swap them once Swish gets going.

Do you buy it?