again, go for the the double jointed!! (: if he doesn't like pinching, get a Egg Butt Double jointed or training snaffle (same thing different name) Or I think is better, is a Loose ring double jointed... my horse used to run away/bolt with a sweet iron in.. double jointed and she like a different horse. And it's a nicer bit!
Unless, your talking about the western TomThumb, im not in the whole western thing, yet (: but im sure someone is.
With your hands, if you only have to stop him with your fingers, as in your ring finger pulling slightly back, now that's a soft hand. If you pull your whole hand back with your shoulder as the leverage point, that's a little harsher, and then you have the reefers. That yank and pull back as hard as they can... so you can kinda decide your self...
Also, you could look at your horses mouth/get someone too or even film it, and see how much your horses corner of there lips are being pulled... and how much pressure the bit is applying.
Hope I helped (: