Hi mav - good to see ya again

Now, darts has always been traditionally scored with chalk marks, and a long line of marks would indicate the completion of scoring throws, so to beat your opponent by a long chalk makes an obvious visual sense..

You're certainly spot-on [is that a dominoes expression? ] here; darts have always been scored with chalk marks. I've no actual recollection of chalk marks being used to score dominoes, and I suppose that would imply a little portable blackboard, as dominoes have to be played at a table. Dunno, there's something about that that rings a faint bell - image of little blackboards built into tables in old pubs?

Certainly pen & paper wouldn't appear in pubs. But I'd presume crib(-bage) boards have been around for years, so why not use them? Even if the ivory pegs get lost you can use matchsticks.