Should events be trained for? Explored, yes. Trained for? Depends on what you find in exploration. LawDawg explored, and had the biker experience. He will vote to keep nelson replies in. I explored, and found them unecessary. I still teach how to address them (Shauns fingers-to-forehead, squirm like hell, bust the guy in the grill), but that's covered in about a 5-10 minute seminar while discussing other techs that share some conceptual themes. In my subjective evaluation, not enough of a threat to warrant more consideration than that.
A single signal only communicates meaning based on perspective. Positioning. I've been a lucky SOB, in that I've always managed to find people to train with who possess hardened, experiential perspectives that appeal to my twisted preferences. One of my profs was a spec ops fellow in Viet Nam, and after. Lotsa good experience to bring to the table. I've managed to land with folks like this over the years. Currently, my training buddy is a retired SEAL who saw duty in Panama, Somalia, Iraq, Afghanistan, and others. Not an amateur in CQB. We have both been impressed by the knifework of a fellow whos stuff has seen action in the deserts; very impressive gent (picture Parker whipping out techs, but they are knife combo's). I will weigh thier opinions more heavily around what works in certain scenarios because of stuff they have seen. They may not be right. Objectively, they may have some glaring errors in approach or reasoning. Subjectively, though, their techs and errors have combined successfully enough with luck to allow us to gather on the same mat to discuss these things.
Objectively, a comprehensive self-defense system ought to have a solution they explore in preparation for a concievable assault. Likely, or unlikely. Note: Chapel says he thinks it's impossible, but he offers a SD tech/solution anyway. My experience of him as a professor is that he's not apt to waste time on something he considers completely useless. I consider the kenpoo techs for the rear full nelson weak, the attack flawed, but still make sure I drill my "assertive spasticity" solution with all my people, because it isn't self-evident in the rush of brawling. And some rehearsal is necessary for success, IMO. So I still address it.
Mr. Slosek wrote:
"...if you're going to train, and the goal is SD, why wouldn't you want to be as effective as possible?"
I would argue that training to remove yourself from a completed nelson is planned failure, which is always a bad theme in training. Some guy starts shooting on you and going for position, do you wait to see where he's planning on going with it before you react, or do you react to your attacker & environemnt and respond to the already extant conditions at hand? Training to be as effective as possible would, to me, invole the idea of working to knock a guy out, or sprawl, or reverse the throw, or block the mount, or escape the mount, or reverse position, or block a hand as it snakes around your throat, or not give up your back, or any of a number of options that present themselves on the way to finding yourself in a rear choke with hooks in...as opposed to working kenpo techniques against a completed rear choke,. If you find yourself there, the technology in your SD tech's that has failed you up to this point won't all at once kick in and provide you brilliant success from within a completed assault.
Sam ting with the nelson. You have all of the fighting ranges available to you that had to get worked through before he had a completed, unlikely control manipulation on you. He likely lobbed a puch at your head on the way in; or shot to a shoulder grab, arm control, or bearhug while transitioning to the nelson attempt; perhaps he approached from "the dark". He probably would be forced to get one arm at a time, giving you ample time to respond. Or, he's trying to slip both arms up and under your armpits, magically unnoticed as his fingers slip behind your neck and interlace. But you have no inclination he's there until he's got the hold completely on, and is compelling you downward? Nah. Plenty of opportunity to respond before this point. If you've let things get so bad that Scraping Hoof is your only remaining option, you suck at fighting and deserve to get tooled in the nelson.
2 scenarios I can foresee that might find you in a completed nelson, and you're screwed in each.
1. Bad guy holds you or loved one at gunpoint while his accomplice places you in it. Bad News = your or your loved one are still at gunpoint, regardless of your twicksy kenpo.
2. You've been in a brawl with multiples, and while messing with a couple of the first bad guys, a 3rd or 4th slips into the dogpile and goes for this, which you don't notice because of the melee chaos, so you find yourself in it, helpless. Bad News = if your losing this badly against multiples, you were going to lose, and were already losing, anyway...this is just a new nail in an already seconds-old coffin. He or his buddies were in the middle of beating the piss out of you in the first place for you not to see it coming.
To be as effective as possible in self-defense would include environmental awareness to see it coming and block it, just like we do when we raise a knee into the guys ribs to prevent him from mounting us from side-mount. It would also include knwledge of structural integrity issues that work for or against you in relative positions, and the ability to use this information to prevent your opponent from destabilizing your neuro-mechanical congruency (have your buddy place you in a full neslon, then try to force you over or down. Push both of your palms into your forehead, while activelt pushing your forehead forward into the palms. Let me know how well the nelson works). NOT just worst-case scenario planning. Otherwise, we'd be learning re-writes of some idiot version of Wings of Silk as a defense against being rear-mounted and choked in Mata Leon. Or is that in Form 4 somewhere?
Be good and train sensibly,
Dave