Join Date: May 2009
Location: Winnipeg, Manitoba, Canada
Keep in mind that all horses are "left" or "right" sided much like humans are, and some can display it a lot more extremely then others. I honestly don't think it's anything you're doing when you're riding, because I'd expect it to be a consistant result, not just on one side. It's moreso that you just don't know how to correct him, and while you continueing riding "normally", it's not what he requires for his stiff side.
I'd say just a lot of practice. Work on a lot of flexing before your rides, get him nice and supple in the neck. I've owned my Arab mare since she was born, and she's 10 years old now and STILL goes all wonky when we track left. She stiffens up her neck, resists bending for me, and would gladly wing her nose to the outside if I let her. I've had her checked out, and it's just a personal thing of hers! Again, this could very well be my fault, since I'm also right handed, I'm better co-ordinated when tracking right.
It can always get better, but just keep in mind that it IS a common occurance in horses and he very well may need a lot more work on that side as opposed to his "easy" side.