That’s a pretty drastic change from where Kopech was at with the Sox last season (4.74 ERA, 1.35 WHIP in 43.2 IP). If the Sox thought he could be that good for a 33 inning stretch and that they could be the team to “fix” him, they would have kept him and traded him next season rather than selling low and dumping him for peanuts.
Maybe he still is the same guy, but the simple fact is that the Dodgers got the best out of him. The Sox didn’t.