Given the Yankee's recent impatience at the plate and swinging at balls out of the strike zone, particularly in clutch situations, this might not be an altogether bad thing.
I'm not sure how much of that can be attributed to the hitting coach and how much can be attributed to the players, but there's no doubt that team used to be much more selective at the plate. I think it has more to do with the players' hitting styles . . . Bobby Abreu, for example, faced more pitches per at-bat last season than any other player in the major leagues.
Mattingly also deserves a lot of credit for almost single-handedly turning Robinson Cano into an All-Star caliber hitter.