Not by a long chalk
Q From Kriss Buddle, UK: Where does the expression not by a long chalk come from?
A This mainly British expression means “not by any means”, “not at all” and often turns up in conventional expressions such as they weren’t beaten yet, not by a long chalk.
It goes back to the days in which a count or score of almost any kind was marked up on a convenient surface using chalk. At a pub or ale house this might be a note of the amount of credit you had been given (often called the chalk in the early nineteenth century), which Charles Dickens refers to in Great Expectations: “There was a bar at the Jolly Bargemen, with some alarmingly long chalk scores in it on the wall at the side of the door, which seemed to me to be never paid off.”
But the expression almost certainly comes from the habit of using chalk in such establishments to mark the score in a game, a habit which now survives in British pubs mainly in the game of darts. A chalk was the name given a single mark or score, so that a person might explain that somebody or other had lost a game of skittles by four chalks or you needed 31 chalks to finish. If your opponent had a long chalk, a big score, he was doing well.
The expression indicates a determined intention to continue, though the game is going against you. Your opponent may have a long chalk, but you’re not done for yet.
For the earliest example, we must turn yet again to Thomas Chandler Haliburton of Nova Scotia, who included it several times in his book The Clockmaker of 1835: “Depend on it, Sir, said he, with a most philosophical air, this Province is much behind the intelligence of the age. But if it is behind us in that respect, it is a long chalk ahead on us in others.”
A related expression is not by a long shot. However, this is originally a military idiom, based on the difficulty of hitting a target at long range, hence an outside chance.