Why? 833 road ops, 861 ops against lhp...so I don't think there's an obvious Coors Field rebuttal here, or something similar. His road OPS was middling or worse until around the Strasburg game, so it surged pretty late as part of the ridiculously unsustainable tear he was on in June and into the very start of July. He's only had 61 PA against LH pitches this year, so it's pretty safe to chalk that up to sample size; him hitting 150 points above his career OPS against lefties clearly is not going to last. And yes, there is the Coors Field factor; Coors, besides it's usual attributes, caters nicely to his strengths (even better than Wrigley; it's often considered the best park in baseball for LH hitters), so in the off chance he has figured something out it's likely largely in part due to his new surroundings. Over his last 30 PA he's put up this line: .154 .241 .192 .434 That's a tiny sample size unto itself, but it's a good microcosm of how wildly his numbers can fluctuate. Tyler Colvin had zero future with the new FO: he's an overly aggressive batter who can't walk and strikes out left and right and can't play defense. Basically the choice was coming down to him or LaHair, and if one is having trouble trying to figure out why they went with LaHair they only need to look to Colvin's 2011 season. Stewart was and is an intriguing buy low reclamation project who plays good defense at a position of extreme need for the Cubs. Colvin had no future with the team; Stewart was effectively a low risk investment who would be far more valuable to the Cubs if he panned out (or pans out) until they found a long term option at 3B.