As usual, I'm a bit weird, with pistols, I use the full hand over hand grip with both thumbs forward over each other, that is 90% of the time, the other 10% comes from grip size or a .22 conversion, rimfire slides won't tolerate even the slightest rubbing from either hand or thumb, so I do the trigger hook on those guns, but the finger does not pull back on the trigger guard, if anything, it supports just under the dust shield for weight. With double action revolvers, I always use the trigger hook method, to keep my left thumb ( I'm right handed ) from coming in contact with the cylinder while it's rotating, and with the smaller 5 shot guns, keep the thumb away from the cylinder gap. Try both grips on a revolver and just look and you will see what I mean. You can get a right side visual from my Avatar. Again, the finger does not pull the trigger guard, if anything it supports the forward weight.