I see the finger choil as a way to develop increased precision, not increased force, on big knives which have all the force you could ever need in terms of chopping power. There is simply no way you can bite as aggressively into material by pushing the blade in versus swinging down at fifty feet per second or whatever a person can develop. But the bigger the knife and the better chopper it makes, the more awkward it is for fine work, hence: the finger choil.

Plus something else I've noticed people doing:



Bad! This is a "point leading" cut. The knife is trying to push into your grip. If your finger slips it's going to ramp up the edge and you're going to have a bad day.

Instead:



A "point trailing" cut. Here the knife is trying to pull out of your grip. If your finger slips, the knife is going to pivot back and away from your finger.