If you lean too far forward in the corner, you'll feel like you're out of control. It's a common problem, and it's pretty easy to fix. The reason this problem hits home with me more is because my wife, Josey, has had trouble with it in the past. I see a lot of novice ropers doing this, and you even see it at the pro level from time to time in certain situations.
The first problem that causes headers to lean out like that is you aren't balanced in the delivery of your rope when you're pulling your slack. Sometimes this is caused by the horse moving out on you, or by your posture in the saddle when you're throwing or pulling your slack.
The second thing is, when that happens your feet go behind you and you can't put weight in your stirrups and push in your stirrups. When your feet go behind you like that as you press on your stirrups, that gives you that out-of-control feeling.
To correct this problem, when you're pulling your slack after the delivery you have to be able to sit back down in the saddle and get your feet under you and maybe even a little forward rather than having them behind you. If you're leaning too far forward in the delivery and when you're pulling your slack, you need to work on not doing that so you don't get totally out of control, like I'm showing you here.
If your horse is causing this by moving out of there, and that's causing you to feel out of control or you're getting your feet behind you because your horse is moving so hard in the corner that you're not able to get back into control, you need to work on holding your horse in when you rope a few times. You don't want him moving sooner than you're ready for him to move.
If your horse drops and sucks backwards when you throw, it throws your momentum forward and his momentum's going away from you. It's such a struggle to get back down into the saddle, and that keeps you out of control all the way around the corner. Rope, pull your slack and maintain forward motion, so you can take control of the situation before you make the corner.
Once you get in control of your horse, have your feet under you or in front of you and have a good seat in the saddle, you need to keep your horse moving forward and widening in the corner at the same time rather than letting your horse suck out from underneath you in the corner. Even when you're in control before the corner starts, if you don't keep forward momentum and a slow widening process with your horse in the corner, you still can have the same effect, even if you are in control at the start of the corner. Basically, you have to learn to keep your horse underneath you and between your feet rather than letting him move out from underneath you and getting you off balance.