I just started leasing a barrel horse off my BO this summer since my pony is a little too slow for me now. I got this horse going again in a snaffle, and we could walk, jog, lope, stop, flex, etc under control, but now that I am doing more fast work with her I feel like I can't control her as easily. She's a really good horse and is always trying to please, just sometimes it takes a lot to stop her or keep her going the direction I want. I tried a tom thumb on her a few times and I had a bit was a bit better but I think the short shanks were annoying her (they were short and straight). I was wondering if this is a reasonable reason to move up to another bit? And if so, what do you suggest?