Despite what some of you have decided to type into this forum on the subject of BloodGrooves in the blades of knives, and their supposed purpose, here is the actual benefit of first-hand knowledge on display for all of you who are as tired as I am of the neverending supply of idiotic and unproven theories on the subject. The purpose they actually serve, in a well-crafted knife, particularly in a shiv, or any flat piece of metal sharpened on one end (no handle material), is this: When in a crowd, an assassin may sink his blade into the kidney of his mark from behind, and not spill enough blood to make the hit noticeable as a stabbing. The victim's blood erupts in a much slighter quantity, due to the lightning-fast in and out "shanking", and therefore, is generally not more than can be caught in the bloodgroove of the blade (much like the principal at work in a child's bubble-wand) until the assassin has had more than enough time to make his way through the crowd, generally unnoticed in the wake of the sharp cry of pain let out by his victim. In my experience, the man is generally assumed to be having either a heart-attack, or a seizure of some kind, until it is far too late for the bystanders who inevitably gather 'round him to be of help sufficient enough to save his life.