I saw this knob today and for 
no apparent reason, the expression “One for his knob” came into my mind. “One for his knob” as an expression has intrigued me ever since I first saw people playing cribbage. And in these wonderful days of the internet, I decided to google it to see exactly what it meant. And having read “One for his KNOB is scored if the player holds a Jack of the same suit as the starter” I am absolutely none the wiser! However, I would caution against googling the expression unless you are particularly broad-minded…