we just don't know. He has faced lesser competition in Korea, so its hard to compare. He wasn't very good in MLB, went to Korea and became their MVP. I think its worth the risk, but we don't know if he will succeed here or not. He wasn't even actually that bad in the majors, to be fair. Huge caveat that he was mostly working in relief, but in 147.0 IP he has a 4.10 ERA, 4.27 FIP, 4.48 xFIP, 8.7 K/9, 3.7 BB/9. Even factoring in the transition to starting, that's the profile of a pitcher who is a few changes away (primarily cutting down on walks) from being a #2/3 starter, and at least in the KBO he fixed the walk problem (1.3 BB/9 last season).