I just thought of this the other day. There's no such thing as a bit that has less than a 1:1 ratio of pressure, is there? I was thinking about this as I saw a small child yank and yank and yank on a poor school horse's mouth, when she needs little or no rein to stop. Poor girl was gaping at the mouth, too.
I'm pretty sure it doesn't, but if I does I really want to know about it!