Many people watch MMA on occasion and aren’t really die hard MMA or fight fans. To these people some of the terminology can be confusing and even sound perverse. The Rear Naked Choke is one of those moves that can definitely give someone the wrong idea about MMA. To someone who does not know what the Rear Naked Choke is, it can sound sort of like what Bubba would do to a young, inexperienced and new prison cell mate. That is not what the Rear Naked Choke is.
The Rear Naked Choke is an MMA submission or choke used to cut off the flow of blood to an opponents head in an attempt to either have the opponent submit/tap out, or lose consciousness. The move was named the Rear Naked Choke because the move is done from behind, or from the rear of your opponent, and does not require the use of the opponents Martial Arts Gei, or clothing to choke the opponent.
When the Rear Naked Choke is applied properly, the arm is wrapped around the opponents neck with the bicep applying pressure on one side of the neck and the forearm applying pressure on the other side of the neck. This cuts off the blood supply and to the brain and thus knocks an opponent out.
Here is an instructional video on how to properly perform the rear naked choke from grapplearts.com, which is probably one of the best instructional videos I have seen on the Rear Naked Choke.