Second basemen Ronnie Belliard was sent to the Cardinals in exchange for utility player Hector Luna. They have very similar batting lines: Belliard is at .291/.337/.420 (.259 EqA), while Luna is hitting .291/.355/.417 (.266 Eqa). Luna is around his 90th percentile PECOTA projection (.292/.357/.422, .270 EqA) while Belliard is hovering between his weighted mean and 75th percentile. Considering Luna is only 26 years old, while Belliard is 31, this is a nifty swap for the Indians, who have been getting younger and younger as July drags on.
Here are the two players' production, measured with positionally-adjusted Net Runs Above Average:
Interestingly enough, not only is Hector Luna not a rental player like Ronnie Belliard, but he's seemingly the more productive of the two. Belliard had the best season of his career last year mostly because he had an above average defensive year. He's regressed to his normal level of defensive production in 2006 though, and it has hurt his value. He's still roughly a league average player, but Hector Luna is the more valuable of the two moving forward. Luna's next four PECOTA projected seasons all look poor, although those were projected before his fine 2006 season. If he can continue to produce like he has, next year's projections will be more optimistic. The Indians can certainly afford to take a chance on his improved production, especially since they were going to let Belliard walk at the end of the season anyways.
It is interesting that the Cardinals didn't just stick with Hector Luna for the remainder of the season; my best guess is that they don't think his offensive production will hold up in the long run like Belliard's should, although the defensive tradeoff seems to be where the real value difference lies. His Line Drive percentage is in line with previous seasons (around 21 percent), and he is right at his expected batting average on balls in play for the year (.330). There is nothing that leads one to believe he will suffer a dropoff in production from this point from his batted-ball statistics, and his season is in line with 2005's .285/.344/.409 performance in 153 plate appearances. A nifty pickup by the Tribe with eyes towards 2007.
As for the player Belliard is actually replacing, Aaron Miles has been consistently poor in 2006. He's hitting a paltry .262/.330/.341 for a .238 EqA, and defensively he's a little bit above average (.827 Zone Rating, .819 League Average). His pNRAA is -8.03, and he was expected to cost the Cards another 3 pNRAA or so in the remaining 58 games. A slight upgrade to Belliard, but Luna would've been a better decision.