Is It Nibs or Nobs in Cribbage?

In cribbage, nobs is the name given to the Jack of the turn-up suit. That is, if the turn-up card is a four of Diamonds, then the player holding the Jack of Diamonds scores an extra point in her hand, known as "one for nobs" (sometimes "knobs") or "one for his nob" (or sometimes "his nibs").

Why is it called nobs?

"Nob" is British slang for "head". So "one for his nob" means "one for his head." On that understanding it makes sense that "his nob" scores 1 point (a real person has just one head) while "his heels" scores two points (a real person has two heels).

What are knobs and heels in cribbage?

By common rules, "his nobs" refers to when any player holds a Jack in his hand which has the same suit as the starter card. "His heels" is awarded to the dealer when the starter card itself is a Jack.