being able to guess what an enemy (either singularly or as a whole) is about to do and understand how you do can get a desired response from them by using psychology.
i.e. playing ring around the rosie with some guy around an obstacle trying to find each other. instead of circling around eachother neither doing something different rather waiting for the other to make a mistake, you have many options, back off a little from the obstacle and shoot them when they come around looking for you, or wait for them and knife, or even head them off and jump around the corner shooting.
This allows you to understand what is happening in the flow of battle and how to stay alive.
i'm not the best at this, and i don't practice it when i just want to play to have fun and not think too hard, but when i'm in the mood and i'm on top of my game it's hard to die unless i want to...to get more ammo or other reasons, challenges.
i like to think of it as applying bruce lee's mentality (jeet-kun do. art of the intercepting fist) to CoD, the fastest warrior is usually the winner. throw a little brain work in there and you're good to go.