When first we met, four and a bit years ago, Derren Brown was a bit of a cult – generating a cool buzz on Channel 4 with his not-quite magic tricks that also mixed in suggestion, hypnosis, “mind-reading” and showmanship.

Then came Russian Roulette, in which he apparently risked blowing his head off live on air. Bang! Nationwide notoriety. How do you top that?

Simple. In quick succession you make Séance, in which you persuade students they are communicating with the dead; Messiah, in which you convert atheists to evangelical Christianity (and back again); The Gathering, in which you hypnotise the whole audience; The Heist, in which you induce ordinary people to commit a bank robbery; and Trick or Treat, in which you drive a man insane to the point of leaping in Trafalgar Square fountain, and convince a careless driver that she is a ghost witnessing her own death.

And you spice up your series of shorter stunts with celebrity escapades, from sticking daggers in Robbie Williams to brainwashing Simon Pegg.

Oh, and you somehow find time along the way to diversify – picking up an Olivier Award for your Something Wicked stage show, writing the book Tricks of the Mind, and making your caricatures of celebrities available for sale on your website.

“I’ve had about three weeks off in these past four years,” Brown says, with no evident weariness or ran-cour. “There are huge blocks of time with no evenings or weekends free. But if I had time off I’d only use it for evil,” he adds, with a devilish grin.

Today, he’s taking time out from conquering America (a mix of new material and old clips on the Sci-Fi Channel), preparing yet another stage tour from February, and writing a second series of Trick or Treat for spring, in order to do voice-overs for a new one-off TV special. In The System, he promises nothing less than to demonstrate a system for predicting which horse will win a race, 24 hours in advance. Every time.

“I realise that this is a farfetched claim,” Brown says, “but it really does work, it’s not hypnotism. I take a member of the public. She gets an e-mail in advance, not mentioning my name, and at the bottom is a racing tip to whet her appetite. She watches, out of curiosity. The horse does win, and she’s intrigued. Then she gets a whole series of tips, and they win, so she starts to bet her own money on it: first a fiver, then a tenner, £20, right up to £150, and then finally a whole lot of money, much more than she can afford . . . and I can’t tell you how that ends because it would spoil the show.”

But you can’t predict a result, surely? What if a horse simply trips?

And if the system is that foolproof, won’t all the bookies be selling up and moving to the Costa del Sol? “The promise throughout the show is that I’ll explain. And when I do, you will see why it has to work. Anyone is free to use the system – though you probably wouldn’t, when you find out how much work has gone into it.”

It sounds impossible, but then so did Brown’s claim that he could take on nine chess grandmasters simultaneously. His system? He gave the first one’s move to the second, and so on – so that, effectively, they played themselves.

“I’m not a gambler,” he explains. “It doesn’t appeal to me. What does appeal is the psychology of it, and the science of winning systems. I came up with the idea out of an interest in systems, and then I had to find out about horse racing because I didn’t know much about it.”

Nevertheless, his card-counting skills have got him banned from every casino in Britain. In a previous programme, he taught a dear old granny to read bluffs well enough to humiliate professional poker players. Why not play himself, and make his fortune? He sighs. “I’d love to if I had the time, but I don’t quite have that delight in sitting up all night. And no one wants to play poker with me now!”

Besides, it seems that, at 36, the mini-Machiavelli of magic is growing up. He discreetly came out in a newspaper column last September – no surprise to those of us who saw the beautiful young man in his wake at a launch party last spring. And when I remark that Brown’s trademark is not so much the mentalism, but his habit of getting the punter to guess an answer rather than watch Brown do it, he gives an unusually candid answer.

“When you get better and better at magic, and get to know the fakery, the science of it, you’re not allowed to communicate that because it spoils the magic, so the only thing you can do is project a personality that’s a bit mysterious. And the public will soon get bored of that.

“So I’ve discovered that it’s important to get away from your ego as a performer. All that’s doing is saying ‘Look how clever I am, to make things appear and disappear’. Whereas to me, it’s all about how interesting and clever we are, how our minds work. Or the opposite, showing when people aren’t so clever, and fall into the traps of mind readers and psychics. It’s all about us, not someone else.”

Horse races notwithstanding, it’s this that could prove the self-deprecating showman’s most winning and unlikely trick – to make himself disappear.

Derren Brown: The System, Friday, Channel 4, 9pm

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