It's hard to quantify Blanco's defense at SS. He only got 90 innings there last year and hadn't played in the majors since 2006. And even at that, he only has 66 total games at SS in the majors. That said, I don't see it as particularly likely that his glove can cover the gap in their offensive abilities. I didn't even think about him not having a big enough sample size to truly get any sort of real indication. Do we think Blanco could be close to a gold glove caliber SS, given what we've seen from him in the field? If that answer is yes, then does it make it close enough value-wise to pull the trigger and deal Theriot? I'll have to make this quick and dirty, but it's a good approximation. If they both perform like they did last season with the bat, the difference between them over 650 PA is about 20 runs. All metrics seem to be in agreement that we are unfairly disparaging Theriot's defense on this board, and most systems rank him as average to slightly above average. For the sake of argument, let's say he's dead average. (which is likely underselling him) Andres Blanco would have to be +20 with the glove to provide equal value. In the last 5 years, there have been a grand total of three SS who have accomplished that feat... Orlando Cabrera in 2005, Adam Everett in 2006, and Omar Vizquel in 2007. Nobody has managed it the last two years. Do you think Blanco would? we're not going to cut theriot and give all his money to blanco, the idea would be to trade theriot for something valuable and play blanco at short in his absence. for the trade to be a good idea, we don't need blanco>theriot, we need blanco+new guy>theriot. and i still don't think theriot is an average defensive shortstop, but that's another matter.