As Bill Ladson notes, the Nationals are giving strong consideration to the idea of shifting Cristian Guzman from shortstop to second base next year, due to what they consider to be diminishing range as he ages. For now, let’s put aside the fact that UZR doesn’t exactly agree with that sentiment and address what shifting across the bag will do to his value:
Over the last 10 years or so, the “advanced” statistics that became popular evaluated players against a position specific offensive baseline – VORP, for example. If a shortstop and a second baseman had the exact same batting line, the shortstop would rate higher by that kind of metric, due to the fact that second baseman hit better as a group than shortstops. As such, it’s become exceedingly common to see people write things like “he’s got enough offense to be valuable as a shortstop, but he doesn’t hit enough to play second or third”.
In fact, I guarantee you that someone will write that very thing about Guzman. The perception will be that moving from shortstop to second base will decrease his value. In reality, if the Nationals are right about his reduced range, it very well could increase his value.
Positions are essentially just a way to arrange players in a manner that produces the most efficient defense possible. You can literally play anyone anywhere – there’s no rule preventing the Nationals from sticking Adam Dunn at shortstop, for instance. They realize, however, that they will field a better team by minimizing the amount of times that Dunn has to move laterally in order to make a play, so they hide him at first base.
No one would think that Dunn would be more valuable if the Nationals lined him up at shortstop. The loss of defensive value would more than offset any gain the team got from getting an extra first baseman into the line-up. So, what I’m saying isn’t even controversial, though it may seem like it on the surface – everyone agrees that there is a point of defensive ability where a player’s value increases as he moves down the defensive spectrum.
If Guzman has lost significant range (again, we’re ignoring UZR and just assuming they’re right about this for the sake of discussion), then it is quite possible that the Nationals will get a larger benefit from reducing the amount of balls hit in his direction than they would by squeezing a marginally better bat into the line-up at second base.
This is where offensive position adjustment statistics, such as VORP, fail. If the Nationals would save themselves 5 to 10 runs a year by having a better defender at shortstop than Guzman, then they’re likely to get a net gain by moving him to second base (assuming that this better defender hits like a shortstop and not a pitcher, of course). And if the move produces a net gain for the team, then it’s impossible to accept that Guzman is getting less valuable in the process.
Now, the Nationals could be wrong about Guzman’s defensive abilities, and they could be marginalizing the value of a guy who UZR thinks is still a pretty decent defender at the position. But don’t just let someone tell you that Guzman is automatically losing value because his offense doesn’t compare as well to the average second baseman. That’s only part of the picture.