A bit late to the party, but this was St. Derek’s response upon learning of the 449th different system of evaluating shortstop fielding prowess to characterize him as a terrible defensive shortstop:
“Maybe it was a computer glitch,” the three-time Gold Glove winner said of the report. But Jeter just didn’t laugh this one off. He defended himself, saying, “Every [shortstop] doesn’t stay in the same spot, everyone doesn’t have the same pitching. Everyone doesn’t have the same hitters running, it’s impossible to do that.”
Jeter, 33, pointed out you can get the exact same ground ball off the exact same pitcher and there could be an average runner or there could be Ichiro running. “How can you compute that?” he asked.
To take these in reverse order, you of course can compute the effect of pitching staff, park, and opposition on fielding; most every modern system does this.
On the positioning, let me outsource to Dan Fox:
None of the systems take into account the starting position of the fielder on individual plays, and so are making an assumption that over the large number of observations—a shortstop would be expected to field somewhere between 350 and 425 balls a year—positioning evens out. That said, the systems also assume (not unfairly in my view) that positioning is a part of what being a good defender is all about. So, if a fielder is claiming that his positioning is making him look bad defensively, which boils down to his not making as many outs in the field as he should, thereby costing his team runs and wins, it’s incumbent upon him to change whatever failed strategy is being employed.
Another way of saying this is “Derek, if you’re standing in the wrong place, you should move.”