Evan Grant has a Q&A up with "The Fielding Bible"'s John Dewan, discussing the latest edition of Dewan's book and, of course, the left side of the Ranger infield.  Dewan is bullish on the impact it will have:

Us: Recently, you wrote that the move of Michael Young to third and the ascent of Elvis Andrus to short would be worth about 40 “saved runs” for the Rangers and that according to your calculations that might equal for more wins. Tell me about your thoughts on Young moving to third and on your theory.

Dewan: “I think a middle infielder should improve as a fielder by moving to third base. It’s a less challenging position than shortstop. And the best asset you can have at third base is a strong throwing arm. I think his arm is strong, fine for third base. But I did point out that he made a number of poor throws last year. So, you do have to be aware of that. Nevertheless, he HAS to be an improvement over their third base play last year. If he’s an average third baseman and Andrus is a little above average as a shortstop, the number of runs they will save is big. It’s a huge improvement.”

As Dewan discusses later in the interview, fielding stats still trail offensive stats in terms of reliability and meaningfulness, but they are getting a lot better.  And I don't think there's really that much question that, if Andrus and Young are both just average defensively for their positions, the Rangers should be significantly improved in 2009 in terms of run prevention.

I've mentioned before that I tend to look primarily at Dewan's +/-, along with UZR and PMR, in evaluating fielders, and Dave Cameron at USS Mariner has a post up explaining why he thinks the UZR method is superior to +/-. 

Nevertheless, if you look at the 2008 Rangers third basemen by UZR, you'll see that UZR agrees with Dewan that they were a collection of miserable fielders, and if you add in the 2008 Ranger shortstops, the left side of the infield in total under UZR was about 25-30 runs below average. 

Now, you may think that assuming that Young and Andrus will both be average defensively next year is a leap of faith.  Personally, I think that may be a tad conservative -- I think both players certainly have the skill sets to be above average defenders at their respective positions.