South Atlantic League average: .251/.318/.362 (Average batter age: 21.5)
Tim Beckham: .305/.353/.422 (Age: 19.6)
Bowling Green Ballpark is still in its first season, so no telling how much the park is affecting his line for the better or the worse. The SAL's average walk rate is 7.7%, strikeout rate is 23.8%, and ISO is .111. Compare that to Beckham's 7.1%, 27.9%, and .117 and he doesn't rate too poorly.
Beckham has the odd reverse-platoon split thing going on. I'd guess that comes from not seeing too many left-handed pitchers in high school or throughout the minors at the time. If not, he's going to be a heck of an outlier.
It's important not to read too far into these numbers yet for someone nearly two years younger than the average player, it's at least somewhat encouraging to see Beckham more than holding his own. Nobody stands in Beckham's way of getting a promotion at some point this season. Port Charlotte's shortstop is Shawn O'Malley; the incredibly fast runner who offers little else.
Do yourself a favor when Beckham does get the promotion, go and see him.