In the Times, Janice Turner wrote that she had been watching Remainers and Leavers ‘like degenerate gamblers, double down, bet all their chips to bag the purest prize, then throw in the farm and their firstborn child. Anything but fold.’

There is much doubling down at the moment. Beatrice Wishart, a Lib Dem MP, said that the Scottish government should ‘face up to the situation they are in and double down on recruitment efforts’. I think she just meant double.

Double down is a phrase from blackjack, an American casino card game resembling pontoon. It entails a player doubling his stake in return for only one more card from the dealer. It is not just the behaviour of degenerate gamblers. By the laws of statistics, it is right to double down if, for example, you have a six and a five and the dealer shows a jack (a knave as Estella would call it).

In blackjack an ace may score as one or 11. It scores as 11 unless that would make the hand go over 21. Any hand with an ace valued as 11 is called a soft hand. All other hands are hard. I wonder if this language too crept into Brexit.

Frankly I do not understand probability. I know that the odds of tossing a coin and getting heads are 50:50, even if you have just got seven heads in a row. That is the joke in Tom Stoppard’s Rosencrantz and Guildenstern are Dead.

A curious word is used to describe a system that convinces some roulette players. It is a martingale and specifies that each time a player loses, he should double the stake. Then he’ll make up all his losses, eventually. The term derives from the town of Martigues in south-east France. Hose that fastened at the back were in the 15th century called chausses à la martingale; the name came into use in Italian and Spanish. Why, from the 18th century, the gambling system took the name martingale is unknown. It might be that, like the men of Gotham, those of Martigues possessed or assumed a foolish disposition.

I don’t recommend the martingale. As someone in Shakespeare said: ‘Double, double, toil and trouble.’