It is important to pick a strong, easy grip that can work in any situation. The fencer's grip consists of gripping your knife between the thumb and forefinger while the other fingers are wrapped loosely around the handle. This grip allows you to quickly slash and stab effectively in all directions. However, it is only really effective for small knives. Larger knives are heavier and slower when attacking, which will leave you vulnerable. You can also lose your grip on your blade with this grip if your hand is hit.
Ice Pick Grip
The Ice Pick Grip allows you to penetrate body armor, heavy clothing and other protective garments. Simply grab the handle of your knife with the blade pointing down and wield it in a stabbing motion, like you would an ice pick. However, this grip can leave you incredibly vulnerable because you telegraph what you intend to do to your opponent, leaving the side you are stabbing with entirely exposed. Also, you can't thrust with the knife, only stab. This grip is best used when your opponent doesn't know you are coming.
Widely considered the best grip, the hammer grip consists of holding the knife handle in a tight fist. Yet the wrist should be loose and flexible, like it would be if you held a hammer or hatchet. This grip keeps the knife from being easily knocked from your grasp and not only allows you to thrust, chop and stab at your opponent, but also punch or beat them with your fist and the knife handle itself.