As far as guards go from various test we made on tires and pig's flesh through the milenia proven method of trial and error it was found that in say reverse grip the best guard one can hppe for even in the heaviest stabs was the thumb over the butt end of the knife. Some found that in the hard way involved with sliced palm and fingers .Hope it helps.The 'Grab-n-Stab ' looms mighty good tool to have