Go Woo-suk stepped up a level after going to the Majors........

The curveball that just struck him out was a trajectory and display of confidence I hadn't seen before he left, wow ㄷㄷㄷㄷㄷㄷㄷㄷㄷㄷㄷ
He is also using the cutter a lot right now, which is also a sign of progress
I'm not sure about his mental game, but in terms of stuff, he has definitely grown