The game of cribbage is comprised of two main parts-- the play, where players take turns playing cards, one after another, trying to reach combinations that are worth points or, alternatively, score a go, and the show, where players show their cards, starting with the person to the left of the dealer (in a two-player game, the person who does not have the crib). Scoring during the show is crucial, as many a game has been so close that the order of the show (non-dealer's hand, dealer's hand, then crib) has determined who the winner was. The value of a hand can range from anywhere between no points and 29 points. The latter is achieved only when a player has three fives and a jack in his or her hand and turns over a five that corresponds to the jack in hand (12 for four of a kind + 8 for fives and jacks for 15 + 8 for the different combinations of fives to make 15 + 1 for his nobs = 29) and is incredibly rare.
The Big Score
The majority of points in a cribbage game come from the show, which is why so many people forego worrying about the play and instead focus on coming up with the best possible arrangement of cards for the big reveal. Players can score points by making runs (three or more cards in sequence in any suit, such as a 3 of spades, 4 of hearts, and 5 of clubs), pairs, cards totaling fifteen (such as 9 and 6), flushes, and having “his nobs” (a Jack in the hand of the same suit as the card that is turned up).
Many cribbage players (especially those in tournament play) will use a rule called “Muggins,” whereby an opponent can claim any points that the player failed to count. This can be particularly deadly when counting fifteens and pairs, as many medium to high-point hands contain multiple counting combinations that are easily overlooked by novice players. Flushes are straight-forward, although some players will miss counting the starter card. His nobs is another point that is often overlooked when counting. Runs, like flushes, are easy to spot, but players sometimes run into trouble when they have a run with a duplicate number (such as 4♣,4♦,5, 6), because this should be counted as two separate runs (4♣-5-6 and 4♦-5-6) and a pair, plus any potential 15 combinations (in this case 4♣-5-6 and 4♦-5-6 both make a 15, for an extra four points). This is further complicated if the starter card is another duplicate number in the run (such as another 6, for this example). Likewise, multiples of the same card (such as three Jacks) are counted by every possible combination of pairs that they can make; rather than calculate the combinations, most cribbage players simply remember that three of a kind is worth 6 and four of a kind is worth 12.
Don't miss points!
In a game where one point can make all the difference, potentially missing out on points (or worse-- giving them to the other player) is something that every one should try to avoid, so it is best to practice a great deal so that one can intuitively understand all the possible combinations in each hand.