Size, Numbers, Surroundings. We know that size matters. That’s why there are weight classes in MMA. In a SD/SF situation, you don’t want to get into a grappling contest, or a boxing match, with a guy who outweighs you by 100 lbs or can put up 400 lbs on the bench press. Rather, use speed and angle to your advantage. With multiple attackers, you definitely don’t want to get tangled up on the ground. The guy’s buddy may kick you in the head or even stab you. As for surroundings, try not to grapple on concrete. You risk serious injury. Use walls and natural weapons to your advantage. And know your escape route.
Non-confrontational hand placement. In a SD situation, there is usually a chance to talk your way out of the situation, to use diplomacy. You walk up to guy like a MMA fighter and you’ll likely instigate un-necessary action. Use what we call the “booby grab”. Neutral stance (no lead). Hands right about chest level, palms out, with a passive, “talking with your hands” approach. The further the opponent, you can lower you guard a bit to avoid perceived aggression. The closer he gets, the higher you place your hands. Outside, low chest level. Kickboxing range, chest level. Anything within striking range, chin level.
There is nothing wrong with backing down or walking away from a fight. If you think there is, you have some serious ego issues. Some guy stares you down, cuts you off on the road, or even spills beer on you at a bar. So what. Be the bigger man. It’s not worth going to prison over. Obviously, if you’re outnumbered or there’s a weapon involved, try to get the hell out of there. You’re not Steven Segal. Don’t be a hero. Heroes wind up dead. Being a “street diplomat” deciding whether or not to use force, is perhaps the toughest thing to learn. Never the less, these is a time for action. Strike first and strike fast. Consider it proactive self-defense.
Assuming you’ve played the non-confrontational role- if you even had a chance- you now perceive imminent danger. Attack the attacker. Strike first. Strike hard. Make him pay. If you let the guy strike first, relying on you blocking/ countering speed, or some defensive Judo/Aikido throw, you’re begging to get your ass kicked. You’re not that good. As for legalities, going to jail for striking first or being a “lethal weapon”, Never mind all that. If the threat is in your personal space, if you’ve tried diplomacy, rest assured, it is self-defense. Besides, it’s the law or your life.
Drunk Uncle, Serious Fight, or Life or Death Street Fight. An uncle or friend had too much to drink. He’s acting out of line and needs to get “sobered up”. The first level is 1 or 2 shots, preferably no blood, and maybe a gentle takedown. It’s different if you don’t know the guy. At a bar, a concert, or in the Best Buy parking lot, this guy is pissed and ready to go, the second level requires a minimum of 3-5 shot. With the third level, the guy is very serious about hurting you or even killing you. He’s bigger and stronger, you’re outnumbered, weapons, the ex-con type, etc. don’t stop hitting till the guy goes town for the count. 5-10 punch combos. Violent strikes to vulnerable areas. Eyes, throat, low kicks to break legs etc.