You can have two rocks or two rabbits, but you can't simply have a two. That's why we distinguish numbers from numerals. Same with odds. A coin will flip with equal possibility of heads or tails. The odds are 50:50, but the actual flip is either heads or tails. Odds are 50:50, reality is either heads or tails. 100 or 0. No fifties.
So before a future post about math and odds, let's look at the rocks.
Thomas, a young German cop, asked me last night about some of the things I'd mentioned here, fighting the mind and my high percentage options and such, and we were able to play with them.
Knives are not mathematical fictions. They are real things that cut and maim and kill. In training, they can be introduced for artificial reasons: "Let's see what works against a knife." Then you give a student a knife and have them fight. Just like sparring but with a knife. It adds a level of difficulty, but it is artificial.
In the real world, knives are used for concrete reasons.
1) A knife can be used to kill people. One of my adages is "Knives are not used to win fights, knives are used to kill people." This goal dictates how it is used. Stealth. Sentry removal tactics. Close range. Weapon out of sight. Control the victim's arm or body or head. Training comes into this. People who learned to kill in jail or prison will do it differently than those who trained in the military. But not that differently. The reason for the kill matters as well. If it is just about money, that changes a few factors. Different than if it is about revenge, or establishing a reputation or a hit...and whether the hit is about removing a problem or sending a message changes things as well.
But in any case, hard, fast, brutal, surprise. Maximum effect and shock, minimum reaction time for the victim. (Survived this once, so luck or not, I know it can be done)
Knives aren't always used to kill.
2) Intimidation. If someone stabs you and you die, the crime, in most places, will be investigated thoroughly. If a threat shows you a knife and you hand over your wallet and no one is hurt, that will not be investigated nearly as thoroughly. Criminals know this. They also know that showing a weapon is more likely to intimidate than being polite.
So knives are used as intimidation displays. The only reason to let you see a knife is if the threat intends NOT to use it. This can go bad, but usually only if you are stupid. Challenge the threat's manhood, try to save face, dare him to use the knife and he just might. This is also the only scenario where a knife defense might look like it does in many classes: a half-hearted knife thrust from well out of range. The regular class stuff might work here, as well... but you have to be stupid to escalate it to here. (Survived this once)
3) The live knife. A trained knife fighter deciding to slice and dice on an unarmed man. This is the training artifact mentioned earlier. It's a challenging tactical problem, but does it happen? I know lots of people who train and play at it, but I don't know any experienced knife thug who would even consider it. The assassination route is safer if you are willing to go there.
4) Rage or fear. You absolutely should practice against certain 'stupid' attacks. Enraged people do sometimes grab the nearest knife or pair of scissors and charge screaming in an icepick grip. Or in fear, pick something up and slash wildly. Some of the old-school stuff, like the figure four armlock, works here. But the same tactics are sometimes rejected because they fail so miserably at category 3. So if "The live knife" as described above is your bench mark, you might not appreciate some things that work in the far more common fourth category, rage and fear. (Survived this once. Overhand scissors to be specific. That 'once' keeps coming up.)
5) Monkey Dance gone wrong. Sometimes the threats escalate and an insecure person draws a knife. It is almost always a dominance display, display being the operative word. Particularly common if the person perceives himself to be out numbered, sees it possibly escalating to a Group Monkey Dance. Thomas described a situation where a friend reassuring the threat that it wasn't a group thing and just a friendly fight talked the threat into throwing the knife away and voluntarily engaging in fisticuffs. Sometimes people amaze me.
Big ego or honest fear of death can also trigger someone to pull a knife when losing a dominance fight.
There may be more, but I think these cover the scenarios I've seen, at least in broad strokes. So, next post when I talk about knife math and knife odds, keep this in mind. Knives are used for purposes and it happens in the real world. Any talk about abstractions, including math, can be a distraction from the world. Be careful.