From the Minor League Ball mailbag:
"I know he probably won't hit .300 with a .500 SLG in a full season, but how good do you think Rob Refsnyder could be? He looked good for the Yankees late in the year."---Jon in Phoenix, Arizona.
Yes, he sure did look good down the stretch for the Yankees, hitting .302/.348/.512 while contributing a pair of steals in 43 at-bats over 16 games. This is certainly at the upper edge of expectations but it isn't as out of bounds as you might think on the surface.
This came out to a 130 wRC+ in context. In the minors, his .271/.359/.402 mark for Triple-A Scranton looks much weaker, but the International League is relatively pitching-oriented and this came out to a 123 wRC+. He ran up a 137 wRC+ at the same level in 2014 and a 159 in Double-A. He's a .290/.380/.432 hitter overall in his minor league career, advancing rapidly through the system after being drafted in the fifth round in 2012 from the University of Arizona.
My thinking on Refsnyder is that he is "really" something like a .280/.360/.400 hitter by nature in the majors and that in a larger amount of playing time his bat will settle down to about that level, in the short-term. In the medium and long term, say the age 27-28 window (2018-2019) it wouldn't surprise me to see him exceed that.
The bigger question here is defense. An outfielder in college, he converted to second base in pro ball. He's not terrible but he's not exactly good at this point, either. He was error-less in 15 games at second base for the Yankees but the advanced metrics don't like his range, which fits the opinion of scouts that he needs more polish to make the most of average glove tools. Of course, a 15-game sample is too small to be meaningful. If you prefer, his minor league numbers show an up-and-down (but generally improving) error rate along with a steady improvement in range indicators.
My thinking with the glove is that he will be an average or even slightly above average defender over the long run, which if he hits as expected will be enough for him to be a fine regular.