One of the techniques we have been working on in jujutsu class is hadaka jime, or naked strangle (the naked designation used because it does not require the gi or uniform to apply it as other techniques do). It is an ancient technique for sure, used in early Greece's pankration (competition combining boxing and wrestling, MMA of the classical times). It is a staple of jujutsu and judo, made its appearance in WWI and WWII combatives manuals, and a modified version is taught in almost all law enforcement restraint systems as the Lateral Vascular Neck Restraint as a court defensible technique to subdue resisting suspects.
Early grappling & striking techniques of Judo
Standing hadaka jime in Judo
Lateral Vascular Neck Restraint used by police officers
What makes this hold so universally practiced? Well, I would say that first and foremost, it works quite well when properly applied, causing unconsciousness in as little as 3-5 seconds when the carotid arteries are sealed, and a bit longer when the windpipe is compressed. The carotid choke is especially useful against larger opponents, as it requires less strength to apply, although somewhat more refined skill to pull it off. It can be used from the rear or front; standing, kneeling or on the ground.
Some variations of the naked strangle
My own experience with the technique prior to jujutsu was as part of self defense technique sets in tae kwon do, and later on as a component of defensive tactics training. After all, if something works so well it makes sense that others would assimilate it to their own ends. Yet I can honestly state that until now I had not experienced the strangle as it was meant to be applied.
So, what's different you ask? For starters, I always thought that if someone tried to apply the strangle to me I would have time to respond appropriately. Guess what? While there is usually time to do something about the choke before it is completed, the time is definitely less than you might think... a lot less. What this means is that a lot of the preconceived notions you might have about what you can do are gravely mistaken. The entire sequence of grabbing the attacker's arm and throwing him/her over your shoulder might not work out so well if you are still gagging from their forearm striking your Adam's apple, quickly followed by blinking lights...
A skilled person can have you cold in no time, even when you know the strangle is coming. How can this be? I've experienced this as a subtle manipulation of my incoming attack, where a firm pull on a limb, a nudge against the side of my hip, or some other seemingly unrelated body twist/push/pinch/etc. gets me moving inexorably towards the completion of the strangle by the instructor without him having to work too hard at getting there. Such sensitivity skill can only be acquired through close body contact work, much like chi sao and push hands. Martial arts like tae kwon do and hard styles of karate do not spend a lot of time on this, as their strategic framework does not require them to do so (their main tactic to forcefully break down incoming attack structure followed by percussive blows to end a threat). Grappling systems, on the other hand, cannot accomplish their goal otherwise.
Another thing I learned: it is somewhat easier for a person with a slimmer or smaller build to effect a strangle (especially a carotid strangle) than a larger one. One of my partners in class is a small frame woman about my age, 5'5" or so and maybe 100 lbs. You'd be surprised how fast you can start fading out once those slim arms are in the right position around your neck! A larger person might react forcibly against someone their size or larger if they feel the choke coming, but a smaller person's arm somewhat snakes along so quickly it might take a second or two to make the connection... a second or two is too long a time space when it comes to a choke IMO.
I definitely have a better understanding of the dangers of the strangle now, and thankfully have not soiled myself in the process of learning about it (although the void did come close a few times so far). I would not say it's one of my favorite techniques (although I've had used it successfully twice on the street), and definitely would not recommend it in most self defense situations (where tying yourself around another person might not be advisable if there might be more than one attacker). Still, it is a common attack (if somewhat improperly executed most times) and what better way to defend against it than knowing how to apply it?