Joseph Jagger knew through his work with textile wheels that no wheel could ever spin perfectly.
So when his business hit trouble and he faced the debtors’ jail, he came up with a clever plan to use this know-ledge to win him a fortune.
In 1881 he borrowed money to travel to Monaco and spent a month watching the roulette tables in the casino, without placing a bet, so he could identify which wheels had the most bias and thus which numbers were most likely to be winning ones.
Then, once confident of the numbers, he placed his bet – and won.
He continued for days and his winnings grew – so much so that casino staff tried to distract the father of four with drinks and women so he would lose concentration.
However, nothing worked and eventually the casino bell rang, signalling that he had broken its bank and won more money than the house had on hand to give.
Determined to stop him doing the same again, the casino spoke to the manufacturer of the roulette tables in Paris and asked it to come up with new tables that could be swapped from wheel to wheel so the same numbers would not keep coming up.
Mr Jagger, pictured, realised his tactics had been uncovered and called it a day – walking away with the equivalent of nearly €8.8million today.
He returned home to pay off his debts and bought 30 houses in Bradford to give to family and friends. He died in 1892, aged 61.
Now Anne Fletcher, his great-great-great niece, has written a book, From the Mill to Monte Carlo, about his exploits.
Mrs Fletcher, a historian from Aylesbury in Buckinghamshire, said: “I grew up on the story of Joseph. My dad used to tell me the tale about how this poor, working-class mill worker had travelled to Monte Carlo and come back a multi-millionaire. It’s a fascinating story to have in the family.
“I come from an ordinary family with no traces of great wealth and it seemed odd that a multi-millionaire could once have been part of it. I am a historian so decided to look into it and my doubts only grew as I researched.
“There was no trace of Joseph in newspapers of the time and his will was not that of a wealthy man.
“I began to wonder if the story had been made up and started a search for the truth. My book reveals what I found out.”
Mr Jagger’s story was overshadowed by the success of gambler Charles Wells, who broke the bank at the casino 10 years later.
Mrs Fletcher said: “I think the casino in Monte Carlo didn’t want anyone to know about how Joseph won because his was a unique method, and so they didn’t publicise his win like they did so many others.
“Joseph, too, was a private man and didn’t want publicity and so he never talked about it. What makes him unique is that he is the only big winner that I found in Monte Carlo who broke the bank legally and kept all his money.
“Often the big winners used fraudulent methods and lost it all by continuing to gamble. Joseph’s motive was not to become rich but to save his family, a desperate but noble gesture.”