I don't think the OP is saying her horse runs full speed INTO a tree. Most trees would stop him if he did that. But can an excited horse run without paying much attention to branches, fences, gullies, or rocks? I'd say yes. If Mia thinks she is 'racing' another horse, about 95% of her focus switches to the other horse. Getting her to listen when only 5% of her brain knows I'm there...that is tough.
And since it doesn't happen in an arena, and pretty much only happens if there is another horse going fast near her...it makes training tough.
Arguably, if you don't ride your horse bridleless, you have a training issue. But most of us don't have the time or inclination to do the many hours of training to get there, so few people say THAT.
But if you don't ride you horse in a bitless bridle, do you have a training issue? True, bits allow a more subtle communication - but using the old "fly on a horse's butt" argument, you COULD train a horse to respond to finger signals on the withers. Run your finger forward = speed up. Pressure on the right means go left. Run your finger back = slow down. Etc. After all, a horse can feel a fly land on its butt, so why do you need metal in the mouth? Why not a fingertip on the withers?
Except it is natural for a horse to follow the nose. It is a clearer, easier to understand signal. And if need be, yes: we can use pain to cut thru the horse's excitement or fear and change the horse's direction. Anyone who has ever been on a galloping horse headed toward a busy road can understand why that might be a good thing.
I think the belief that a french link snaffle is THE
bit, and anything else is harsh, cruel, and indicative of a training gap comes from the ENGLISH
approach of riding a horse "on the bit". I guess if you are constantly fussing with your horse's mouth, then you need a lot of caution about what you put into it. And I can sympathize with that, because Mia LIKES to feel some contact with her mouth. It seems to reassure her that I'm there and we're a team.
Personally, I prefer a slack rein. With Mia, we compromise - just a LITTLE slack. Trooper gets a lot of slack. The difference between how the two horses like to be ridden is captured in the picture below, with my daughter on the Appy Trooper and me on Mia:
In an environment like that, both horses can be ridden fine bitless:
But if you put Mia outside the arena without a bit, you are asking for trouble. Is that a training issue? Of course. But after 4.5 years, training it out of her may be more than I can accomplish. The trainer I hired who came over 4 times/week for 3 months, and then 2 times/week for 3 more months, said her favorite horse is like Mia - and that after 15 years of owning her, she will still get very wound up at times. Her recommendation was to plan on never riding Mia without a bit.
All that said, it doesn't mean the FIRST reaction to a horse who doesn't stop (and it always seems to come down to that) is a harsher bit. Even with Mia, I've come to realize I must always
stops from her at a walk or trot. In the arena or on the trail, it doesn't matter. She needs to stop quickly, squared up, and relax with every
cue to stop at a walk or trot. No fidgeting, no moving around - just stop as quickly as is safe, feet in a rectangle, head level, no fuss, no fidgeting, no resentment. If she won't do that, then she won't give me an adequate stop if excited. Expecting a 100% effort to stop and relax every time at a walk and trot is the minimal training that is safe for her - unlike some horses, who like stopping!
I like the elevator bit because Mia seems to understand it. This is it:
I went with a single joint, because Mia doesn't like french link snaffles.
Neck reining, she does fine in it. Direct reining, an opening rein to the left is enough for her to understand left. If she wants to fall into the circle, slight pressure on the left rein will tilt her nose in. And at those levels of pressure, it essentially acts like a standard snaffle.
But if she gets wound up and doesn't want to stop, then pulling back with both reins does the same as it does with a loose-ring snaffle - except that it adds pressure on the poll. That additional
cue seems very instinctive for her. And using an additional cue for the horse is a lot milder than increasing the pressure on the snaffle in her mouth.
Going to a curb bit also isn't mean or harsh. By the time the curb strap takes effect, the horse has already had a cue to the mouth, and then poll pressure...and then
the curb strap will engage. Assuming, of course, the rider isn't an idiot who just snatches back full force on the reins. And the fix for that is training the idiot rider, not condemning a class of bits. It seems better to add cues outside
the horse's mouth, than add pressure inside
Sorry for the essay, but I get frustrated with the idea that Mia has the same needs as Trooper, when they are very different horses. At the same time, I get frustrated when someone grabs a twisted wire snaffle 'to make their horse mind'. I've joked about putting a car battery in the saddle bag and running a wire to the bit, with a big red "STOP" button on the saddle horn...but I'm getting nervous that someone will think that is a good idea. There needs to be a middle ground, combining training with tack the individual horse understands.