This is my first FanPost so when I inevitably butcher something, please be gentle.
To me he clearly had the speed, athleticism and baseball IQ to suggest he'd put it together, but everyone bashing his defense through the minors certainly had me a bit concerned about his long term future at second. Obviously, many have been pleasantly surprised with Ackley's defensive acuity for the M's thus far. I haven't read a single report that suggests he hasn't passed the proverbial eye test since his callup (although I'm sure there's one somewhere in the vast internet expanse). For what little it's worth, he's looked quite capable to me as well.
Defensive stats are pretty worthless with a ten game sample, but so are offensive stats and that doesn't stop anyone from noting his team leading OPS or second best OBP. So my curiousity got the best of me and I decided to take a look at his defensive numbers. Do the early returns confirm or deny what we're seeing with our eyes?
Well, with a ginormous SSS disclaimer, the results thus far are at least encouraging. According to Fangraphs, his UZR at this point is 2.0. His UZR/150: 35.7 (!). Obviously, I'm not ready to declare him Dustin Death To Bouncing Things Ackley, but the premature UZR seems to suggest that we could be looking at a legitimate defensive second baseman.
Personally, I don't see any reason to think Ackley can't develop into a +5 to +10 run gloveman at second. That might even be a tad conservative. He may not have traditional second base movements, but he certainly makes second base plays.
I know everyone's already excited about Ackley, but I think he might be more exciting than we even realize.
UPDATE: To those allergic to UZR, Defensive Runs Saved (DRS) has Ackley at 4 above average, which is higher than his UZR. Obviously, the numbers themselves are meaningless at this point, but all available signs seem to point in the same direction.