According to David Pinto's Probabilistic Model of Range, Bobby Crosby was the second-best full-season shortstop in the AL last year at getting to baseballs. (The model, as its name implies, does not attempt to measure arm, nimbleness in turning the deuce, etc.) In the AL, Mike Aviles, Jed Lowrie, Erick Aybar, and Alex Cora ranked above Crosby, but none of them played anywhere near the 145 games that Crosby did. Who was the #1 full-timer? Our old friend Marco Scutaro! Actual Gold Glove winner Michael Young grades out as have almost exactly average range.

Unless the A's have a hidden defensive whiz hiding in the minors, or steal Mike Aviles away from the Royals, they're going to take a defensive hit when Crosby leaves after this year. (And when Ellis leaves two or three years hence. And when Jack Hannahan gets replaced at third base this year. And when Daric Barton .220's his way out of the lineup. It's a remarkable, and remarkably underrated, defensive infield.)