Obviously the best way to win a bar fight is to never get into one in the first place. Most fights start after someone escalates the situation which causes adrenaline that quickly results in physical aggression. By simply staying calm and trying to be passive as possible it's often possible to simply dissolve the situation before it starts. It might not make you look big but it will keep your face nice and pretty.
Don't be afraid to run away. All the best fighters in the world agree that it's often better to run from a fight than to end up reflecting on how poor an idea the whole fight thing was in the first place from a hospital or prison bed. At the end of the day if the worst that happens is you escape completely unharmed aside from perhaps a slightly battered ego you haven't done too bad. And you can always console yourself by pretending that if it had come to blows he would have come off worse. So really, you did it to protect the other guy.
If things are going to come to blows, get the first one in. If the guy is shoving you and it's obvious there is going to be a fight, don't let him get the upper hand by hitting you first. Paul Ivens of London Shootfights says that often the first punch is enough to set the tone for who will win the fight anyway. If you manage to get in that first blow you may just put them off their guard long enough to win the fight. Even if they are considerably tougher than you.
The One Hit KO
You've seen it on the TV and obviously in a fight the best thing to do would be to win within a single punch. The good news is, one-hit knockouts are not just reserved for the professional boxers. A right or left hook to the side of the jaw should be enough to knock anyone out cold. The reason most boxers keep their chins tucked within their hands is for this reason alone. If the guy is going to start the fight by sticking his face in yours, return the favour by placing your fist to the side of his mouth and watch him go out like a light.
Apply The Vulcan Death Grip
Ok so the Vulcan death grip would be a cool thing to do, however, in the hands of a normal human it isn't so easy. Luckily there is a real technique based on the similar pressure points which can be used to quickly finish a fight. Applying pressure to either side of the neck for a period of about 5-10 seconds is enough to put anyone to sleep. Commonly known as the sleeper hold and easier to apply from behind, this technique is a great simple way of ending the fight in a nice, gentle way as you slowly ease your opponent to sleep, cooing “nighty night” in his ear.
Get them on the ground
Trip them up, knock them down, do whatever it takes but keep them off balance. You're far more likely to win a fight if they are on the ground. In fact, regardless of whether you ultimately win or not, if you've managed to knock them down you're going to be able to claim some form of bragging rights. Keeping them down stops them doing nasty things like hitting you or kicking with their full force, something you're going to be thankful for if they keep attacking you.
Don't go to the ground
Don't let them knock you down! As soon as you hit the ground you're at their mercy. Even if they go down, don't drop to the ground yourself. Once you’re on the floor it's easy for someone to sneak up behind you or kick you as you're tumbling with your opponent. Try and keep to your feet, and resist any temptation to finish them off if they do go down themselves.
Watch your back
Be careful of their friends. It's not so easy to start a fight yourself, but when someone is watching you give their best pal a good kick it can sometimes trigger a response within their friends that tells them to do something honourable like hit you from behind. Try to keep your back to a wall or friendly people to avoid getting sucker punched.
Run away again
Once again, don't be afraid to run away. In an ideal world you'll have knocked down or put your opponent to sleep allowing you to be able to get some kind of breathing room from the violence. Don't use this time to gloat. Instead just get out of there before they regain consciousness or get up for another go. Maybe stop for one cool blockbuster movie style line, then make sure you run for the hills.
Of course the easiest way to win a fight is to only go to local bars and pubs where you already know the bouncers. Having a solid crew of 6 and a half-foot ex-army guys at your back is almost always the best way to win a fight. For the sake of the odd beer now and again you'll find it exceptionally easy to befriend these benevolent behemoths that will come to your aid should the necessary time arise. After all, the best time to plan for war is in a time of peace, especially if it's over a nice pint or two.