Somebody once posted here that he splits anything too large to palm (pick up) with one hand by grasping the end of the split. I thought that made a pretty easy rule when you're out splitting. I take it to mean that I have to fit my hand over the end and also pick it up and toss it with that same one handed grip. If I can't toss it I split it again, but I have a small stove so I want smaller splits.