In team roping, good equipment that fits and is adjusted to your horse is always essential to your success, because it directly affects how he works. And while everything from the bridle you use to your saddle pad is important, there's so much more, from how he's shod to his nutrition. Team roping is a sport with so many variables, you've got to have each one under control to maximize your horse's performance.
To use one example on the nutrition side, a lot of horses from Oklahoma and Texas are fed coastal or prairie hay that's sometimes supplemented by grain. Then they get hauled out West to rope, where they predominantly feed alfalfa, and you have to be careful, because those horses will get hot. It never looks good for a horse to look poor when team roping, but there are some horses that get high as a kite if you go to pouring the feed to them. They might even think about bucking. As you constantly evaluate your horse and his performance, there are so many things to consider.
Having a horse's teeth checked on a regular basis is part of routine maintenance. That's one of the first things I check, even when I'm trying a horse. A lot of times I'll feel one's mouth to see if his teeth are razor sharp. That can darn sure affect a horse's performance. A really good horse will give you his life no matter what. But most horses won't work as good when they aren't feeling good. Another sign of teeth that need attention is that a horse will slobber his grain out and spill a lot of his feed. Some horses will take their hay over to their water and soak it to tender it up a little bit before they eat it. That's another sign that a horse needs to have his teeth worked on.
When a horse goes to shaking his head or gapping his mouth open, something is wrong. He might need his teeth done, or he might just be over-bridled. You need to check his mouth, and reevaluate what's in his mouth. It might be pinching him, or just be too much for him. If something's hurting him, he's going to try to get away from whatever's bothering him.