Let me take a different direction, because what you're looking for isn't really what you think it is. You want skills that will work under a specific pressure. You need to shape your training towards that pressure, instead of towards the ring or sparring. If you do that -- it doesn't matter what you train in. I suspect that the Systema folks hereabouts will tell you that it's impossible to learn Systema from video or in the way that you're describing because there's more to Systema than the physical techniques.
Look into the reality based self defense movement. Take some of their exercises and drills, and use your boxing skills within in those drills.
I believe I explained myself improperly. There are 3 reasons I study martial arts - sports, self defense, and offense. I'm not saying that I'm gonna grab a knife and slice everyone's throats if I feel threatened, but I will feel a lot more comfortable if I will know how to properly use a knife in battle for example. That's why I'm leaning more towards military martial arts - they not only teach you to defend yourself but to break joints and bones, fight with a knife/stick and even kill with your bare hands(or with a weapon). Such moves are not taught in any of my local classes.
@jks9199 I'm sorry, I'm not sure I understand what you mean.
In your original post, you wrote:
After 3 years my gym closed, and so did my boxing class. But I still wanna continue training. I've been attacked several times during my life, and it taught me the same thing again and again - I am not capable of defending myself. I rock at the ring(best in my class), but in a real battle it's harder to control myself. Especially because there are *always* numerous attackers, and it's *always* a surprise. And please trust me when I say I do my best to avoid danger, and it still happens.
So anyway, I would like to learn something more modern and actual for today's streets.
Full points: You've already realized 2 truths about real violence on your own. The odds are never fair, and attacks are typically unexpected.
But you've locked into the idea that there's some system out there that'll give you the answer to how to survive a fight. There's not. There is no system that will, in and of itself, prepare you for real violence. Instead, there are training methods that will do the job -- whatever the system you train in. Taekwondo is an easy example. There are many people who go to TKD classes on Tuesday and Thursday, and practice their patterns and one steps in class, and spar... but would be completely lost if you actually threw a punch at them. But... the ROK Marines base their hand-to-hand on Taekwondo. Or Taiji (tai chi chuan)... The slow hippy dancers aren't much to look at. But if you ever have a chance to have someone really skilled show you the combative applications, you'll be scared silly. It's a cliche -- but it's not the system, it's the person that matters.
You're looking for the ability to actually apply your skills in a real situation. That takes a particular type of training. There are several ways to get there, ranging from practicing classical koryu kata to Peyton Quinn's bulletman suit or other variants. Rory Miller will give you a lot of tools if you buy his book Drills: Training For Sudden Violence. (Shameless plug for someone I really need to actually train with, rather than bounce ideas. Consider anything of his worth the money; I do.) You have to expose yourself to realistic situations in a controlled environment so that you can then apply the lessons learned in chaotic environments.
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