"keep the belly perfectly flat" no, keep it tillered evenly. perfectly. flat is a way to gain a easy to see tiller. i dont agree with the "flat" stuff. as for its the only way to tiller it. but if your newer, flat is the way to go. heres a question. when you tiller the bow flat on the belly. does the edges of that flat belly do anything? no! sooo, if you got rid of those edges, im talking a little bit here what happens? you loose limb weight correct? so now theoretically if the limbs weight less they should move faster back to brace ? so in the end you end up with what i call a lensticular type tiller seeings how the back isnt flat like a board. well unless you cut down a huge diam. tree. then if you have medium growthrings, yea you could get perfect flat back. but most times its not. just my thoughts. but if you never worked locust, of any sort, yea flat works . but whats most important that its dead perfect tiller! and not over stressed as you make it.otherwise, get a check here ,get a check there , get a check everywhere.Tony