Out! And so am I, by £40,000

The UK gambling industry is worth billions. But just 5% of customers are responsible for 70% of that revenue. Those are people like Hannah Jane Parkinson, desperate and deluded, watching their lives fallapart. Here she tells how she lost tens of thousands to date) and investigates an industry beset by corruption and organised crime

- HANNAH JANE PARKINSON

It's the middle of a third set tie-break on Wimbledon's Centre Court, and 15,000 tennis fans are clapping to their own beat, whipping up anticipation for a crucial line call. Hawk-Eye, the automated line system the tournament uses, the tennis equivalent of a Roman emperor's thumb - able to overrule the traditional linespeople with their ostentatious crouching - flashes on to the big screen. The clapping reaches a climax: Jannik Sinner, a wiry, 21-year-old Italian has hit a backhand long by a few centimetres of the All England Club grass. A few minutes later, he loses the tie-break - and I lose £800 ($940).

In the preceding two years, I have lost much, much more betting on tennis. I have lost £40,000. I didn't see it coming, the gambling addiction. Even now, I wince a bit at the word "addiction", though that is plainly what it is. "I really wish there had been a warning that gambling was addictive," I joked to a friend, though neither of us was laughing - at that point I was worried about paying rent and bills. I had lost all of my savings. I'd "spent" an entire book advance.

Along with many people, I still imagined gambling as the preserve of bored middle-aged men in rundown high street shops; Ladbrokes and William Hills nestled among kebab joints and pawn shops. Stubby pencils, receipts littering floors, rising voices as dogs with prominent ribs raced around a track on a TV screen. Often, that's not the way it is any more. Nowadays you can bankrupt yourself via an app on a mobile phone, or a never-closed browser tab.