In reply to spidermonkey09:
I think a chisel is when you kind of bend the tips of your fingers outward at the first knuckle so you get a larger contact with your tips on the hold but you still get that nice bent main knuckle for strength, it's a bit of a weird one to be honest.
If I pull half crimp on a small enough hold it will tend to pull my fingers into a chisel anyway so you don't get much choice.
(I might be wrong by the way but that's my interpretation)