Mathematician David Robert Grimes was skeptical about Ryanair's double-your-luck claims (AFP/Getty)
Mathematician David Robert Grimes was skeptical about Ryanair's double-your-luck claims (AFP/Getty)

Ryanair steward's claim that 2-for-1 scratch cards 'double' your chances of winning roundly debunked by mathematician

'No Dice O'Leary' says mathematician in dismissive post on Twitter

Ronan J. O'Shea
Tuesday 05 December 2017 19:39

Flying Ryanair is a game of luck at the best of times, but a mathematician claims to have debunked a member of cabin crew's claim that buying two scratch cards for the price of one doubles the odds of winning.

David Robert Grimes, a doctor of physics and postdoctoral researcher at Oxford University, was travelling on the no-frills airline when he took exception to the claim that buying two scratch cards for the price of one would drastically boost a passenger's chances of winning.

The scientist posted a picture of a notepad on Twitter with a scribbled calculation working out whether what the airline said was true.

Concluding that claim was inaccurate, Grimes scribbled "No Dice O'Leary", in reference to the airline's chief executive, who has had a difficult year at the airline, with pilot shortages and complaints over Ryanair's seating policy.

The airline has also come under fire in the past with accusations that it does not pass on profits from its scratch card sales to charities, as it claims.

Grimes told The Independent: “In his defence, if your chances of winning per card, p, are absolutely miniscule, then the claim that buying twice the number of cards 'doubles your chance of winning' is not a bad first-order approximation.

"Certainly it's less of a mouthful than 'increases your chance of winning by a factor of 1 + (1-p)^n'. Though the only way the claim could strictly be true is if your chances of winning are absolutely zero, or if you buy zero cards - probably not the ringing endorsement Ryanair intended.”

Grimes conceded that the airline's slogan was "more catchy" than his calculation.

He was keen to note that calculations like the one in his tweet are "quite removed" from his usual line of work, which focuses on mathematical modelling of tumours and science writing. “It's all a bit of fun pedantry," he tweeted. "I was simply procrastinating on a short-flight instead of actually being productive, but as most of my work consists of cancer modelling or debunking dangerous pseudoscience in media, it was a pleasant distraction. Promathstination if you will.”

It's not the first time experts have disputed Ryanair's claims. Earlier this year, Oxford scientists worked out that there is more chance of winning the lottery than beating the airline's "random" seating allocation policy.

In this case, Ryanair, and its long-suffering cabin crew, can probably stick with the more "catchy" claim.

Ryanair told The Independent: “All of our 129 million customers are already a winner thanks to our unbeatable low fares and our scratch card game offers great prizes including cash, luxury cars and the chance to win €1 million, while supporting charities across the UK and Europe. We also offer a bundle of 7 cards for the price of 5!”

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