I have heard that too and the people that I have heard say it are former pitchers. And a pitcher can tell if a baseball is off in even the slightest way. If pitchers are saying the balls are wrapped tighter, that is gospel as far as i am concerned. One night watching an out of market game, I hear an announcer/former pitcher (can't remember his name) talk about this, and he also talked about opening the ball to see see the construction. He thinks that the baseballs are definitely different this year.