One of the things Bill James learned while inventing Sabermetrics was that a lot of what one perceives as pitching is, in fact, fielding. However, one of the things I've learned is that fielding responsibility is very difficult to apportion individually. There are 'fielding theorists' who argue that you have to start at the level of the player, with stuff like fielding percentage or zone rating. I'm more inclined to see it the other way: you have to start from the top, then start sharing out the blame further down. However, nobody knows the truth! Nothing's been proven! How do you evaluate defensive statistics anyway?
Defensive Efficiency Rating was a Bill James' invention, I think, which basically tells you what percentage of balls hit into play against a team are converted into outs. It's a bit deceptive in that not all balls hit are really playable. This demonstrates that some of what one perceives as fielding is, in fact, pitching. It's useful, nonetheless, in giving a rough idea of one team's defence in relation to another's. By this measure, the Nationals rest at the bottom of the league, with a DER of .695. This is very bad, considering the Dodgers are at the top with a DER of .729. That means out of every 100 balls in play, the Dodgers convert three more of them into outs than the Nationals do. Now, realistically, that means about one ball-in-play per game. But over 162 games that's 162 hits, or worth something approaching one Chase Utley per season. Would you like your pitchers to face Chase Ultey in every game?
The Nationals aren't good at turning the double play (13th in the league). They're good at making errors (1st in the league). They're last in putouts (but 4th in assists—they must like helping old ladies across the street). They're also worst in fielding percentage. And that's about all you can say at the team level.
Well, except the good folks at The Hardball Times have published a team Revised Zone Rating. (Kind of like DER, a rate of converting balls in play into outs, but one that allows for those hard-to-reach balls.) Yes, the Nationals are last, at .809. (But Milwaukee's best, at .860.) However, they take it a step further, and break RZR out into Infield RZR and Outfield RZR. Nationals' infielders manage to be 14th in the league, but the outfield is dead last.
So, I'll conclude this analysis with the current Ultimate Zone Rating* and Revised Zone Ratings by player (minimum 60 innings at position), then tell you what I think Mr Riggleman ought to do.
Player UZR Change UZR/150 Change RZR Change LgMedian
Zimmerman 9.6 + 2.0 16.8 -1.0 .739 -.018 .716
Johnson - 4.6 + 1.8 - 6.8 +3.6 .752 +.023 .778
Guzman - 3.9 - 0.1 - 6.7 +0.4 .757 +.003 .802
Hernandez 1.2 - 0.3 2.6 -0.6 .844 -.002 .813/.801
Dunn (LF) -11.7 - 2.2 -27.4 -4.1 .813 +.001 .865
Kearns (RF) 0.1 + 0.6 - 3.2 +2.4 .881 +.004 .916/.910
Willingham (LF) - 1.8 + 0.4 - 5.3 +1.2 .905 +.003 .865
Dukes (CF) - 5.9 + 0.1 -21.8 +1.5 .898 n.c. .947/.943
Harris (CF) - 4.7 + 0.2 -14.4 +1.0 .936 +.001 .947/.943
Dunn (RF) - 6.8 + 0.1 -34.1 +1.0 .756 n.c. .916/.910
Belliard (2b) - 1.1 - 2.5 7.0 -2.0 .869 -.012 .813/.801
Gonzalez (ss) - 3.1 - 1.1 -22.4 -7.3 .682 -.036 .802
Dukes (RF) - 0.2 - 1.1 - 3.5 n.c. .952 n.c. .916/.910
Willingham (RF) 0.2 - 0.2 1.5 -4.2 1.000 n.c. .916/.910
Morgan (cf) 0.7 n/a 4.5 n/a .938 n/a .947/.943
Dunn (1b) - 3.1 - 1.1 -42.8 -7.4 .600 -.114 .778
Gonzalez (2b) - 0.9 n/a -14.5 n/a .773 n/a .813/.801
Well, really, I don't see what Mr Riggleman can do that Mr Acta hadn't done already, by taking Dukes out of centre and keeping Dunn out of right. Is there any room to improve the infield? Belliard's numbers were good earlier on, but he's been in sharp decline since getting more playing time. Use him in games with flyball pitchers. Gonzalez is sinking like a stone. He's worse than Guzmán now. Nick Johnson shows some improvement this week, balanced by Zimmerman's decline. My one piece of helpful advice—keep Dunn OFF first base. Don't listen to the Sirens calling for Johnson's trade because Dunn can fill in at first. Hecan'thecan'thecan't.
* Ultimate Zone Rating was developed by Mitchel Lichtman, one of the authors of The Book. (See link to blog at left.) It has to sum to zero, which is why players who get no playing time still see their numbers change each week. It's highly regarded, and gives you a number that represents runs saved (the pluses) or given away (minuses).