This post from John Dewan about the best projected defenses has been making rounds, mostly for calling the Red Sox the most improved team, with 87 runs gained in fielding value. Since the Mets didn't crack the most improved list, but likely couldn't replicate last year's abominable performance if they wanted to, I estimated 2010's squad in runs above average.
Firstbase
2009 UZR: 5.4
2010 projection: 3
It's hard to see Daniel Murphy and company going too far over 5+ runs in 2010, especially if Mike Jacobs or Chris Carter makes the team.
Secondbase
2009 UZR: -12.2
2010 projection: -10
With Luis Castillo and Alex Cora both coming back, there's not much room for improvement here. Castillo is supposedly working to improve his range at camp, but I won't hold my breath.
Shortstop
2009 UZR: -8.4
2010 projection: 0
We need Jose. Depending on how he plays and how well he plays, this position could be a source of huge improvement. At least Ramon Martinez is gone either way, though.
Thirdbase
2009 UZR: -10
2010 projection: -4
Like with most of David Wright's 2010, we're left hoping 2009 was an anomaly. It probably is, to a degree, so at least a modest rebound can be expected.
Right Field
2009 UZR: -6.4
2010 UZR: 0
It's hard to optimistic when much of the positive value in RF last year came from Ryan Church and the negative from Jeff Francoeur. Still, I'll take the over here, not necessarily because of Francoeur, but because Fernando Martinez is waiting in reserve, where Jeremy Reed and Gary Sheffield were last year.
Centerfield
2009 UZR: -9.5
2010 UZR: -10
Angel Pagan with Gary Matthews Jr. as backup is worrisome and it is hard to know what to expect from Beltran when he returns. If Carlos returns quickly and plays well, this number will obviously be different, so let's hope for that.
Left Field
2009 UZR: -6.3
2010 UZR: -8
I didn't expect the Mets to find a more-established left-fielder who could replace injured-Gary Sheffield and be just as bad, but Jason Bay just might. Here, his playing time could prevent players like Angel Pagan from mitigating against some of his poor play, like they did for Sheffield last year.
Adding up totals, that is -47 last season, second worst in the majors, and a projected -29 this coming season. An improvement of 18 runs, but still a pretty bad defensive team.