Using zone rating, here are the best and worst defenders through Saturdays games. The methods used can be found in archives of baseballthinkfactory.com, I did an article on it last year and Chris Dial did several others.
I haven't changed anything for 2b, 3b, ss, and OF - I use putouts (OF) and assists (IF) to determine how many chances each player gets. All players are compared to the MLB average at their position, not their league average. I think this is the correct way to go as long as they do interleague play. For 1B I am abandoning my convoluted formula to determine chances, and just using the average chances per inning played from Dial's article.
I haven't done anything this year for arm or DP ratings, its just zone. No park adjustments have been made.
1B: +5 Shelton, +4 Niekro, +3 T Clark
-7 Konerko, -5 Giambi, -5 E Perez
Giambi's no surprise, everyone knows his best spot is DH. Perez is really bad in limited playing time. Kendry Morales is +2 in limited innings. He had reputation as a poor glove, but from the games I've seen this rating is accurate. He has surprised me with some great plays at 1B. He looks better there than Casey Kotchman, and about as good as Erstad. So far at least.
2B: Polanco +9, A Hill +7, Grudz +6
-12 Weeks, -12 L Castillo
Polanco is one of the best every year. Perhaps Hill should be the SS, and Russ Adams at second? Adams does not seem to have the arm for SS. Adam Kennedy is at -3, he's usually a plus defender. Still better than Kendrick or Figgins, but if Kennedy is losing a bit of range, and also turning 30, its best to let the kids take over next year. Weeks is no surprise, his 18 errors alone assure he'd rate poorly. Castillo is a bit of a surprise. Maybe he's having trouble learning to play on turf.
SS: A Everett +12, +7 Eckstein, +6 Counsell
-8 Furcal, -7 Berroa, -6 Renteria, -6 Tejada
Everett was the defensive star of John Dewan's Fielding Bible. I won't get started again on Eckstein. Orlando Cabrera is at -1, close enough to average. I've come to like the OC, he's a good player, just a bit overpaid. He's done a good job setting the table in 06 so far. Jeter is at -5.
3B: Feliz +10, Chad Tracy +7, Lowell +6
M Cabrera -10, Batista -9, E Chavez -6
Chavez rates low despite only 2 errors and 19 double plays - an amazing total for a 3B at this stage of the season. Counting the DP's he's still probably above average overall. I wonder if he's got some injury that's hurting his range? Or maybe its just a fluke so far. Cabrera is ther for his bat. He wasn't so good in the OF either, his destiny is probably 1st base just like his father, Albert Pujols.
LF: Langerhans +8, Swisher, Floyd, D Roberts +6
P Wilson -13, M Ramirez -8, A Dunn -8
Wilson was a bad CF, but I thought he'd be about average in a corner. He's not hitting much either so Houston will probably have to find another option. Manny Ramirez, when you consider the Green monster, is having a pretty good year by his standards. David Pinto, in his probabalistic model of range, showed a huge split in Manny's rating for home and away, most of the big negative was at home, though I can't remember exactly what the numbers were.
CF: Abercrombie +6, Cameron +6, Pierre +6, Patterson +6
Matthews -6, Markakis -5, K Robinson -5, Griffey -4
Griffey is not nearly as bad as he was last year. He's real stubborn about moving out of CF though. He should be a corner OF, and if he was AL the debate would be should he start DHing or not. Patterson has caught everything hit his way for the O's. He's fun to watch. Abercrombie has some serious tools, makes some great highlight catches. Too bad he has no clue that there is a strike zone. Erstad is +3 in limited time. Nice transition back from 1B.
RF: B Giles +6, J Guillen +5
Burnitz -6, Cuddyer -6, Lane -5, Mench -5
Don't have much to say about them. Vlad at +1, also 5 assists.