Newly minted Pirate icon, centerfielder Andrew McCutchen is on the verge of stardom. A great hitter with good plate discipline, McCutchen is also a terror on the basepaths. The only thing holding him back seems to be his defense, or at least it seems that way according to UZR. In 2009, McCutchen ended with a -1.8 UZR/150 rating. So far this year in approx. the same amount of games hes sporting a ugly -13.1 UZR/150 rating. Now, due to the nature of advanced fielding metrics, this is still a SSS but McCutchen would have to be getting extremely "unlucky" if he's really the great to elite defensive CF scouting reports indicate he can be.
Because McCutchen is only in his sophomore season, there is obviously hope. McCutchen has time to learn how to take better routes and get better jumps to take advantage of his world-class speed. Still, one may wonder, despite allegedly taking bad jumps and routes (hence why Cutch needs to work on them) is McCutchen really that "bad?"
I'd like to propose an idea/question using my limited understanding of UZR. As such, I'd like everyone to weigh-in and share their knowledge.
The pirates are notorious for employing a "no triples" defense. In my understanding, this moves the LF in a better position to cut off the deep left-center gap to prevent triples (and gives up more of the line). Consequently, the other OF's are moved as well. Such an alignment may affect UZR from working "correctly." The following is a quoted paragraph from a article on fangraphs.com about UZR and its inner-workings. I've bolded and italicized the specific part that caught my eye.
Now what about the hits? There were 79 hits in zone 56 while Bordick was playing SS. Surely he is not responsible for all of those hits. How many is he responsible for? Well, since an average SS catches 294 balls in zone 56 out of 1419, or 20.7% of the outs, Bordick is responsible for 20.7% of the 79 hits as well, or 16.4 hits (the third baseman is responsible for the other 62.6 hits). I told you it was going to be tricky!
Basically, the entire system is based on how many balls a player should get to in each "fielding zone" and that number is compared to what how many balls the "average" fielder is able to field (it's actually % of balls gotten to in each zone - the entire league is used to prevent SSS). So to determine Cutch's UZR's each "fielding zone" is examined and his ability to get to the balls hit into each zone are compared against the league average. Well, if Cutch is shifted over a significant amount, he won't be able to get to zones to his right (our left looking at him) and balls will drop, hurting his range "score." Considering he's having to range further than your average, more centrally positioned CF, Cutch is getting unfairly judged. That is extenuated by (as I understand it) Tabata (or Milledge earlier in the season) taking Cutch's chances because only the player catching the ball gets the "point." Basically, our LF is stealing Cutch's range rating, which may explain why our LF's have seemingly had inflated UZR ratings recently.
I will note again that this is a theory and I'm not sure that even if this were true, if it would significantly affect Cutch's UZR. I'm not also sure how to exactly factor in if he is getting a "bonus" in the zones in right-center, being closer to that way and if that may offset any "penalties" he gets in zones in left-center. My gut feelings seems to think our shift has Cutch further away from our LF than our RF, which means my theory may still apply. Also, it would seem Cutch would have a better score in right-center zones that may normally be fringe zones for CF's but that wouldn't be good enough to offset more traveled zones he's further away from in left-center.