The knife game, pinfinger, nerve, bishop, stabscotch, or five finger fillet (FFF), is a game wherein, placing the palm of one’shand down on a table with fingers apart, using a knife, or sharp object, one attempts to stab back and forth between one’s fingers, moving the object back and forth, trying to not hit one’s fingers. The game may be safely played with the eraser side of a pencil. The order in which the spaces between the fingers are stabbed varies. In North America, the most popular version is to simply stab all the spaces in order, starting from behind the thumb to after the little finger, and back again:
1-2-3-4-5-6-5-4-3-2 (repeat)." There are a number of YouTube videos with this challenge as well as challenge fails. It's pretty obvious when you fail at this challenge what can happen.