Neck Crank Compliation

[gone_postal]

Where I train Brazilian Jiu-Jitsu, neck cranks are very discouraged. I do not know the reason, however I think its the instructor's personal preference. We do not learn them.

Well I get bored, and I read up on other martial arts/systems. Well, a common thread seems to be neck breakers, especially what I hear about the SCARS system.

More or less I want to know:

1) Is what you see on the silver screen based in reality (when dealing with neck breaks)?
2) Are neck cranks reliable submission holds?
3) Does what you see in reality-based self-defense systems work?*
4) How are some of the ways are neck cranks set up and from what positions? You can ignore the crusifix, and full nelson.

*For example, I saw a demonstration on YouTube of Krav Maga. The person closed the distance, threw fake knees to the midsection, and pushed the opponent away from him. He then proceeded to grab the chin of his opponent with his left hand (the opponent was in front, moving to his right), then pushed down on the right shoulder with his right hand to hyper-rotate the opponent's neck. It is neck cranks like this of which I am talking about.

[Zendetta]

I'm coming to see neck cranks as uncool in BJJ circles because they allow that athletic wrestler who doesn't know subs to wreck your comfie bottom game.

My traps, levators, and scalenes are still feeling the maniac who took my lunch money saturday night.