We turned Kovalchuk into the league's best PKer and a responsible player in the defensive end. Defense can be taught, offense is much more challenging.
Lemaire turned Kovalchuk into the league's best PKer, while DeBo has struggled with guys who don't fit the system. Also, Kovalchuk, despite all of his flaws, wanted to be coached. If Yakupov is clashing with coaches over system, it's not going to be as easy to fix him.