Good to know.that sweet spot that you're talking about is the center of percussion. However when you're making deep cuts with a chopper you will get deeper bites by hitting behind that center of percussion because then the impact is driving the handle up into your hand which puts some of the mass of your arm into the cut. On a competition chopper your power zone is an area between the guard and the middle of the blade. The tip of the blade is where you develop tip speed and go for things like straws and rope.