Sam Fuld vs Darin Mastroianni (and Alex Presley)

If you prefer to evaluate the defensive prowess of baseball players with your eyes, look no further than this clip to see exactly how good Sam Fuld can be in the field.

Darin Mastroianni, as serviceable as he's been over the last couple of seasons, didn't seem capable of making this caliber of play. He made some good ones, but I don't remember seeing anything like this. But it's just one play, and truth be told, Fuld isn't likely to get any more playing time than Mastroianni had been.

Fuld does have a high grit and hustle factor, though, so when he does play this is the kind of speed, glove, and effort that the Twins are going to get.

But, getting to those pesky numbers - how much of an improvement over Mastroianni is Fuld? Let's turn to FanGraphs.

Career numbers can hide achievements as well as sins, and it's certainly what ESPN 1500's Derek Wetmore believes, too. Fuld's biggest apparent advantage is in the corners, but Wetmore points out how one good season with a good sample size skews those numbers to be better than they normally would be.

Sam Fuld had a very good defensive season in LF for the Rays in 2011. Outside of that, he's pretty much Alex Presley.

— Derek Wetmore (@DerekWetmore) April 20, 2014

While Presley's defensive metrics don't exactly bear out Wetmore's impression, the comparison between Maestro and Fuld, on the defensive side of things, does tell us a couple of things.

• It tells us that Fuld was definitely the better right fielder (in spite of the slight difference in Mastroianni's favor under the UZR/150 metric). Fuld has a significantly better record at making the outs he should make, and he's also more likely to get to balls that most right fielders shouldn't.
• Fuld's range looks better in left field, but his conversation rate leaves something to be desired for a guy who is supposed to be a plus defender. In his "very good defensive season in LF for the Rays in 2011", he posted a career-low .844 revised zone rating - essentially, he only made 84.4% of the outs that he should have made. Maybe Fuld was flashier, but it seems like Mastroianni was the more reliable option.
• Center field is basically a push, although Fuld has a great deal more experience at the position at the Major League level. Maestro's arm was more or less good enough, but it seems Fuld's arm is better suited for the corners.

This data only covers 2012 and 2013, so we're dealing with small sample sizes, but we're looking for the big picture here: Fuld certainly seems to have better range, and probably a better ability level, in the outfield. It doesn't mean he'll come out as the better player at every opportunity, but my impression is that he'll certainly give his pitcher a better chance for a big out in the depths of the outfield when he needs one.

Offensively, it's a bit of a push. Mastroianni's career wOBA is .263, career wRC+ 62, career OBP .288; Fuld's career wOBA is .291, career wRC 82, career OBP .312. Fuld is also four years older, now in his age-32 season, which as far as I'm concerned more or less negates any incremental advantage he may have had.

Is Sam Fuld going to win any more games for the Twins than would Maestro, or even Alex Presley? Unless the game depends on a last-second diving catch in an outfield corner, probably not. Fuld hasn't been the same since a foot injury and his spark plug-like aura in 2011, but the defensive ability still looks like it's there. That, and his experience in all three outfield spots, is most likely what this seemingly inconsequential move is about.

We'll see Fuld in uniform on Tuesday, and if all goes according to what we expect he'll also get a start on his first day in uniform.