Wednesday, February 6, 2013
Granderson has been exclusively a center fielder since joining the Yankees in 2010, but does have some previous experience in left field for the Tigers and has drawn some criticism for his defense recently. Meanwhile, Gardner has always played left field alongside Granderson, but he was a center fielder in the minors and would have stayed there for most other teams.
At this point I’m certain that Gardner is a better defensive player than Granderson, so he should be in CF since he’ll see more chances there. I’m also certain Granderson will be gone after this year so for 2014 it’d be smart to get a feel for just how good Gardner can be in CF.
When you flip two defenders the impact overall isn’t going to be huge, maybe a handful of runs over a full season, but with the apparent decline in the Yankees’ overall projection as of right now they really need to take every single incremental chance to improve themselves.
As far as what the impact might be, let’s consider these numbers.
The average CF sees about 462 chances per year. The average LF sees about 365. Granderson’s got a zone rating of .853 over the last two seasons which means he’s converted 85.3% of the chances he’s seen into outs. Gardner’s got a career zone rating of .920 in CF in his career, although that only encompasses 183 games. He’s got a .904 career zone rating in LF. We can split the difference which ends up at .911.
Not all chances are equal and the angles of the balls that CF see vs. LF may skew this somewhat, but let’s assume that Granderson would have a .85 zone rating in both LF/CF and that Gardner would have a .900 zone rating in both LF/CF.
Granderson CF/Gardner LF: .85 x 462 + .9 x 365 = 721 outs
Granderson LF/Gardner CF: .85 x 365 + .9 x 462 = 726 outs
So you’re looking at a difference of about five outs, or four runs if both stayed healthy and played every game this year. The real-world impact is probably closer to three runs. It’s worth doing, but it probably won’t have a huge impact.