PA....BA...OBP SLG OPS EQA VORP RF ZR...Name
129 .284 .354 .353 .707 .261 +3.7 5.12 .800 Alex Cora
144 .281 .326 .356 .682 .242 +1.2 4.88 .870 Mark Grudzielanek
137 .264 .304 .302 .607 .225 - 0.6 4.69 .857 Cesar Izturis
058 .367 .466 .510 .976 .336 +7.1 8.15 .750 Eric Karros
033 .200 .394 .360 .754 .274 +1.0 7.44 1.00 Todd Hundley
146 .276 .336 .448 .783 .276 +5.9 9.86 .878 Fred McGriff

Explanations:

Baseball Prospectus stats:
--EQA: A measure of total offensive value per out, with corrections for league offensive level, home park, and team pitching. The EqA adjusted for all-time also has a correction for league difficulty. The scale is deliberately set to approximate that of batting average. Average is .260.
--VORP: Value Over Replacement Player, calculated in such a fashion that I'm not sure how it's done myself.

Other stats:
--RF: Range Factor, calculated as [(putouts plus assists) divided by innings].
--ZR: Zone rating. The percentage of balls fielded by a player in his typical defensive "zone," as measured by STATS, Inc.

Observations:

1) These stats catch players in the middle of some hot streaks (Cora, Karros, Izturis, McGriff) and one big cold streak (Grudzielanek).

2) That said, for the season to date, the Dodgers have better offense at second base than the Cubs do. On defense, statistically, it's harder to distinguish between the two. My sense is that Grudzielanek has gotten harsher criticism defensively than he's deserved. All in all, though, Cora appears to be the better of this almost gruesome twosome.

3) It's good that his batting average is rising, but Izturis is still going to have to hit more than singles and the occasional double to become even an average offensive player. Defensively, these stats also don't appear to reflect what we all think is his true value.

4) Had the Dodgers kept Grudzielanek and started him at second base with Cora at shortstop, the team's numbers would have been slightly but not significantly better.

5) Playing mostly against left-handed pitching, Karros is doing well for Chicago, and is 8 for 15 with two walks in May. Playing every day, McGriff has raised his numbers with a fairly hot May of his own. At this point, the exchange of McGriff for Karros simply seems to have helped both teams. Their alternates at their position with their respective teams, Hee Seop Choi and Mike Kinkade, bat from the opposite sides, creating the opportunity to maximize output. Dusty Baker has taken better advantage of this than Jim Tracy so far.

Conclusions:

I think that the trade of Karros and Grudzielanek for Hundley (with McGriff signing as a free agent) has been as positive as either team could have expected. It was a mutual salary dump, but so far, there has been no harmful fallout. None of the additions or subtractions is dragging his team down. There is an onus on both teams, however, to react promptly if and when the stats of any of the involved personnel decline - and in the case of Grudzielanek, that moment may have already arrived. Tracy and Baker must carefully massage their weaknesses.