[MIEventer]

Never use inside rein to direct your horse back to the inside. Always use outside rein.

So if he is drifting to the right *more than likely because your back needs realigning and you are causing the drift* then you use our right leg behind the girth and right rein on his right shoulder to direct him back to the center.

You can pull their face all you want with your inside rein, but that isn't going to cure the issue. You must direct the ribs and the shoulders. Your outside leg directs the ribs, and your outside rein keeps that outside shoulder under your horse, which then in turn gives your horse nowhere to go, but to the left.

You have to block their energy from flowing in the incorrect direction.

So if your horse was veering to the left, left leg and left rein on the shoulder.