One of the most bomb proof horses I was around came from a bucking horse contractor of all places, a percheron cross. The guys saddle was loose and did not mention it to anybody. Anyway off he came,saddle and rider tangled under his belly. That horse stopped dead in his tracks and didn't move a muscle till someone got that guy out. I think its more the horses individual personality than their breeding that makes them a little more safer to ride than some.
Same thing happened to my dad many years ago although he was leading the horse with a deer on top of the saddle. The horse just planted her feet and stayed put until he could get the cinch undone to resaddle her. You don't find too many like that.
