Okay, I've been driving my gelding for about 3 years. And he's always done this. Not sure how to fix it or if I can. When I drive him, he always pulls to the left a little. I keep my right line tighter to keep him straight. Acts like his alignment if off!There is nothing physically wrong with him or the harness. I drive him in a half cheek snaffle driving bit. Should I change bits??? Any suggestions????