I’m pretty sure that, all other things being equal, bigger-stronger guy has the advantage.
Why else would they have weight classes in competition?
Ali at his peak would defeat Leonard at his peak for sure.
I forgot to add: the aim of self-defense is not to beat the other guy up, it’s to either disable the attacker so you can run away, or put him into a secure hold and call the police.
In any martial arts style, there’s a basic defensive position, where you can cover the vulnerable parts of your body and your balance can’t be broken. You open yourself up everytime you leave that position to attack. In competition, you only score points if you attack, so both open themselves by attacking.
But in self-defense, the defendant can win if all he keeps doing is to defend himself without ever attacking (just dodging and deflecting). Yes, it doesn’t sound bad-ass like Bruce Lee beating people senseless, and it wouldn’t look showy. But it works.
Some boxers use this technique to exhaust the opponent with greater weight and less stamina - keep them coming, evade and deflect, until the other collapses from heart attack. 
Because, like I said, the heavier guy, once he is moving and therefore, off-balance, easier to throw down with a circular movement.
A bigger guy has a higher center of gravity than a smaller guy and is therefore easier to throw than vice versa.
A heavier guy has to move more mass around, which affects his stamina.
If you look at two black belts from the same style, but with different body types - one distintivly smaller than the other - you can see how the smaller has the advantage. I have seen many fights in front of the class by higher belts instead of official competition and it is easy to see.
Not because the bigger would win easier, but to make things more equal so you compare only the skill and not the other factors.
Sorry, I don’t know who you mean here. What kind of martial art and what people are you talking about?
I’ve only seen a little MMA on the tube, and the stronger guy sure seems to have the advantage there. Inertia is overcome by strength, with a little extra power left over. I’m not talking a fat guy vs a skinny guy. I’m saying that 180 lb of skilled bone and muscle will have an advantage over 160 lb of skilled bone and muscle.
Two of the best fighters who have ever lived:
Ali
and,
Sugar Ray
With Muhammed Ali being the absolute best.
I think it would be interesting to see Ali at his best vs that little guy you’re talking about, at his best. Both would, of course, train specifically for that fight.
Cecil!
I’m shocked!
You overlooked the female yellow-belt in karate who, among other things, disarmed the man who tried to rob her hairdressing shop.
Reference:
<http://www.russiatoday.ru/Top_News/2009-04-14/Hairdresser_turns_robber_into_sex-slave.html>
God yes, same here. When I was 18, I had taken classes in female self defence. I had learned to deliver a killer backwards kick. Then, one night a couple months later, I stood waiting at a gas station, when I felt a hand stroking my butt.
I don’t know why I looked behind me before I delivered that kick. As I wore heavy booties, my kick could have crushed a shinbone. But I looked over my shoulder before kicking.
Behind me, his face on knee height, was a little toddler smiling up at me, his hand raised to pat my butt again to get my attention for whatever it was he wanted to show me.
Apparently being out of it for years can erase some of the muscle memory. Several years after stopping martial arts, I was skating and fell. I threw out my right arm and landed on my hand and broke my wrist. A year later I went back and took some more martial arts.
My wrist still bothers me to this day 
I also had a girlfriend who took several years of martial arts, including training how to fall. One day she was running through a park and ran over one of those park table-benches (with the wooden benches attached to the table). On her descent, the bench broke and she fell. Instead of tucking and rolling, she threw out her arm and broke her elbow. Some weird instincts!
Yeah, well, well trained anyone is going to take me down regardless of their weapon. I wouldn’t go against my Jujitsu Sensei even if I had a gun and he was unarmed. I’d assume that he would win.
I want to be clear that I don’t think going up against someone with a gun is advisable. If you can talk your way out of it, go for it.
Stranger on a Train is dead wrong though that a gun is deadlier close quarters than a knife. You can control someone’s gun hand as easily as their knife hand. Once when training with one of my old Sensei’s I had a practice knife and he got my hand in an arm lock and took me to the ground. I let go of the knife and caught it in the other hand and drew it across the back of his knee where the femoral artery is. That’s a killing shot. The look on his face when he felt it was priceless, I’ll never forget it. I would’ve had a broken arm but he would have been dead. So Stranger makes it sound like controlling someone’s knife hand is an easy task.
Measure for Measure Obviously yes the exit velocity of a bullet is more than the water from a water gun, but still even Jet Li isn’t going to be fast enough to dodge water AFTER the trigger has been pulled at ten feet. You have to dodge before the trigger has been pulled. Again it’s only a simulation, not a perfect representation of a bullet travelling 700mph.
EDIT: I think **Stranger **probably knows far better than I do, and he probably COULD control someone’s knife hand. I’m just pointing out that it’s not as easy to control a knife hand as he made it sound. He’s talking about a trained person controlling a knife. It’s also much harder to control a knife when you have a gun in the other hand. Also if I were working with a knife and someone were trying to control my knife I’d be slashing at the arm and hand that’s trying to control. You can exanguinate someone from extremities as well.
My Kung Fu instructor asked us once who the most dangerous person in the room was. He pointed to one of the black belts who had a broken rib. And the reason was not because he was a black belt but because he had a broken rib, so he’d fight like a wounded animal.
In competition fighting you aren’t trying to maim the dude, you are trying to pummel them into submission. The constraints of competition give the big dude the advantage. In a real fight everyone has weak spots. There is no way to really protect your throat just because you are bigger. Knees are still weak and a kick straight down on the top of a knee cap will still shred the patellar bursa just like it will on a smaller guy. The bigger guy definitely has SOME advantages, but being big won’t make your Jaw that much proportionally more strong, or the bridge of your nose, or if you get put onto the ground it won’t help you against a knee with 150 lbs behind it slamming into your temple. The problem with competition is that the dirtier tricks that give the advantage to the smaller guy are things you don’t really want to do because you are not trying to damage them permanently.
Overall the plusses do go to the bigger guy. The advantages of being small, if any, are miniscule by comparison.
I wonder, do the (MA) teachers tell students that size doesn’t matter? Or do they teach them how to try to overcome the disadvantages of being smaller.
I know that in boxing your coach won’t tell you that size is nothing. They teach that size is an advantage, and how to try to onercome that advantage. Of course, the bigger guy learns how to counter that training.
Boxing is a sport, not a martial art in the way real self-defense arts are.
Realy! How about kick boxing? And I’ve quite a lot of boxing going on in televised ma contests.
Remember, the competitive stuff isn’t self defense. Not at all.
Kickboxing, Tae Kwan Do, Karate, Judo, Kendo, Boxing, Wrestling, they are all sports not martial arts in the same way Krav Maga or Jiu-Jitsu are martial arts.
Martial arts includes, eye gouges, throwing sand in people’s eyes, cutting their cheek open with your keys, slamming their hands or their heads in car doors, dropping your knee on their temple, spraining or breaking their neck, dislocating their jaw, kicking them in the balls, breaking their knee caps, hitting them with your shoulder, clawing, elbowing, headbutting, biting off someone’s ear.
If any of those things are not allowed it’s a sport, not a ‘martial’ art. It’s the arbitrary limitations set upon the competitors that makes it a sport.
Kickboxing is the sport version of Muay Thai in the same way Judo is the sport version of Jujitsu or Kendo is the sport version of Kenjitsu.
Reading threads about martial arts gets me so angry. Even on a board devoted to fighting ignorance, threads on martial arts inevitably devolve into idiotic regurtitations of urban legends.
For instance, I’m having a lot of trouble believing that a supposedly intelligent person would honestly believe that being bigger and stronger isn’t an advantage in a fight.
The sort of mindset that can believe this comes only from complete lack of experience competing against real opponents. Go train BJJ or Judo, or boxing and all your delusions about size and strength not being a factor will be completely washed away.
And the garbage about sport v. martial art is the same misinformation thats cropped up every frigging generation for the last thousand years. Every generation forgets that “sports” version of martial arts start up because people realize that people who train non-lethal techniques full-strength against resisting opponents can beat people who train “lethal” techniques that, because of their nature, can’t be trained full-strength against resisting opponents. How many times over human history is this fact going to have to be relearned?
If it’s the “martial” you have a problem with, then I can see your reasoning. The point of boxing it not to kill your opponent, but simply to knock him (or her) senseless. Scoring is merely an alternative so there can be a winner in case both go the whole match. The point of most sports is to take territory or a prize, not a captive.
There are a lot of adherents to those other disciplines you mention who are going to be annoyed with your opinion. 
Is a Jiu-Jitsu compitition match not martial art?
Ever heard of Ralph Gracie? There’s a Ralph Gracie Krav Maga/Jiu-Jitsu school right around the corner from me. One of several, I hear.
Maybe I’ll present him with the OP’s question.
What was the question?
My friend once asked me is I had to fight Mike Tyson or Bruce Lee which would I choose? No doubt in my mind I would fight Mike Tyson. I would be far more likely to be able to out run Mike Tyson than Bruce Lee.
I have to disagree with that. It’s not the martial art, it’s the martial artist. The entire “Martial Art A vs Martial Art Z” is hogwash. It’s who’s better trained in the discipline that they study.
And what was said earlier about the use of the voice and running - Preach It, Brother! Those are the second best self-defenses possible. The best is using common sense: controlling your environment and making sure you don’t get into bad situations.
Heh. That’s why I like 'em. I would feel differently if there was anything other than anecdotal evidence. Along those lines,
Um, cite that ju-jitsu is worse for self defense than sport martial arts? I would think that Krav Maga would be optimized for the battlefield while Boxing training would be optimized for the ring. Some of the skills would transfer of course. I find your argument plausible but lacking real evidence that’s as much as I can say.
I find your argument plausible but lacking real evidence that’s as much as I can say.