Well, I don't think that is true, altho the few times I've seen horses jump in the creek, who knows if they thought they could clear it, or were just jumping in:)
If you're walking up to something, or even trotting, you can tell when the horse is gathering themselves to jump, and have time to take action either get ready for it, stop them, or rein them back to keep them from it...which doesn't always work:)
Becky
People pretty much know how far they can jump. I just wondered if a horse does too, like over ditches and stuff.