I was a bouncer at a notorious nightclub: These are the secrets of the job – including the only way to answer the question, ‘How much have you had to drink tonight?’

It sounds like some nonsense you wouldn’t see in a Kung Fu movie, but I promise you it’s true.

Just by looking into someone’s eyes I can tell if he or she is going to be a problem or not.

Romance novels would have you believe that the eyes are the window to the soul – I’m not entirely sure about that, but I can tell you that they are a window into whether a heavily tattooed postcode gangster is going to punch you in the jaw or not .

He’s not some pseudo-philosophical tough guy. It’s basic psychology.

Direct eye contact, especially when there is hostility, is a dominant trait.

Avoiding eye contact, even for a split second, is submissive.

That’s why boxing and MMA fights stare down after the weigh-in.

Let me give you an example of when I risked my life and limb by running through the doors at one of Australia’s most dangerous nightclubs (number 2 on NSW Liquor and Gaming’s list of violent venues, to be precise).

If you tell someone something they’re not going to like, like, “Sorry buddy, I can’t let you in because we’re almost full,” and they look away for a moment, I know right away that I can. resolve the situation without violence.

Even if they get aggressive and yell at me.

On the contrary, if the person does not avert his gaze and looks directly back at me, there is a reasonable chance that I will have to strangle him.

Now it’s important to note a few things.

Just because someone looks away doesn’t mean they aren’t dangerous, or that they aren’t a skilled martial artist who could easily kick me.

Fully patched bikers and career criminals were regulars at the location I worked, and when I had to line them up, the meanest and most notorious goons would often look away.

It wasn’t because they were submissive or afraid of me. It’s because they didn’t mean to beat up a simple bouncer in front of cameras and witnesses.

They might have stabbed me in the parking lot after work or drove by my house, but at that moment I knew they weren’t ready.

Likewise, just because someone looks back doesn’t mean he or she is a good street fighter.

An attractive 6-foot woman in high heels who isn’t used to people telling her “no” is unlikely to break eye contact in my experience. And she is usually ready for conflict.

Although she is unlikely to become physically aggressive, she will make up for it by shouting disgustingly and throwing insults at you.

The only other caveat I would add is that when someone is into drugs, all bets are off when. You just can’t predict what they’re going to do.

It may seem unfair, but there’s a very good reason why goons like me police the city’s trendiest locations so tightly.

It comes from a common expression in the dark world of security: ‘Stop at the door.’

Basically, this means that if someone gets into trouble, it’s much better for the conflict to take place outside the venue than on the dance floor, where other patrons can get caught in the crossfire.

There is nothing more awkward than when someone refuses to leave a crowded room and becomes aggressive.

A typical encounter would unfold as follows.

Some deadly thug would hit another customer, sexually assault our bar staff, or literally urinate in the corner of the room (I’ve seen this).

“Sir, I’m afraid you have to leave,” I would say.

They’d reply, ‘What are you going to do about it, f*****?’

To be honest, it’s a very good question: what am Am I going to do something about it? There are few options.

You can stand there and engage in an endless discussion hoping they will change their minds – which never works and will inevitably lead to physical conflict.

Or you can try to grab the gentleman in question and wrestle him out the door in front of hundreds of clubgoers.

Because there are too many obstacles between you and the door, this is not a good plan.

There are too many opportunities for him to break free and throw punches, and this could lead to an all-in brawl in the middle of the dance floor if or when his friends jump in.

It’s always best to avoid hitting someone, for legal reasons of course, but mainly because it’s too easy to crack your hands on the skull.

When a belligerent postcode gangster challenged me in a room, I felt the best option was to simply choke them unconscious where they stood and carry their motionless bodies outside with the help of a Samoan colleague.

I looked them in the eye, told them to leave, and when they looked away, I knew there was an option to resolve the matter without violence, and then I gradually walked them out.

But if they were to play again, I would give them fair warning. And if that were ignored, I would cut off the blood supply to their brains by compressing their carotid arteries – either with my arms or with their own collar.

It takes about five seconds for someone to pass out. It’s quick and painless, at least for me.

If at any point during this process you considered calling the police, you would never make it as a bouncer.

The police do not have the time or manpower to participate. Plus, it looks bad for the location if cops show up every night, and it would immeasurably damage your badass reputation if you had to call for help.

Reputation is everything to bouncers, because if you show any kind of weakness, people will take advantage of it – or even try to outrank you.

A tipsy 21-year-old girl might get up and dance on a table for laughs. Harmless fun, right, what’s the problem?

Well, if something like this isn’t checked, within about ten minutes everyone will be dancing on tables and someone will break their neck – for which you and the venue will be liable.

So it’s crucial that you set the tone.

In cases where clients threw punches before I could strangle them, one of the best ways I found to discourage others from doing the same was to headbutt them.

Of course, there are safer and more practical options for self-defense, but nothing sends the message that you are a ruthless psychopath than the simple act of headbutting someone in the eyebone.

Although I wouldn’t do it again. Only for those rare occasions when an unusually large number of criminals, bikers and murderers visit your establishment.

So, how to use all of this to your advantage on a night when you’ve probably had too much to drink but still want to visit a late night spot.

The first test is usually at the door when the bouncer asks, “How much did you drink tonight?”

Many people fail at this.

Unless you’re absolutely plastered, the bouncer won’t care how much you’ve actually drunk. He or she is just gauging your reaction to find out whether you are aggressive, argumentative, or unreasonable.

Instead of stating an obvious lie, just do this.

Look away for a moment to show that you’re not going to be a problem, then say something like, “Oh, we had a few drinks, but nothing serious.” How was your night?’

Asking a question helps because aggressive people don’t talk politely.

And even though 99.9 percent of doormen have no conscious understanding of micro-expressions or psychology – eye contact is evolutionary – so it will work automatically on a subconscious level.

I mean… unless the bouncer is totally insane.

Levi Parsons now works for Daily Mail Australia as a Night Editor