One of the key strategic decisions in Cribbage is discarding. You are dealt 6 cards and must choose 4 to keep, the other two go to the Crib (either yours or your opponents). A card is cut after the discarding decision is made, so one must account for uncertainty in that card in the decision-making.
The full game state relevant for discarding is the 6 cards, player score, opponent score, and who has the upcoming crib.
Skilled humans typically weigh a couple of different things when discarding:
Expected value of the hand for possible 4-card combinations that could be kept. I don't do a full calculation in my head as that is beyond my mental arithmetic abilities, but I typically run through all possible card combinations in my head and note which combinations have a good chance of combining with many possible cut cards to increase their value.
Expected value/loss for the cards thrown to the crib. There are a few heuristics for this:
You can find tables of average crib values for all possible discard combinations derived from historic tournament play. Expert humans typically memorize these to one decimal place prior to tournaments, and could be leveraged in a computer agent.
A common rule that I typically use is that (5,5) is worth 4 points above average, (5, Any Ten card) is worth 2 points above average, (5, Any other card) is worth one point above average (though (5,6) and (5,4) are worth more), and (2,3) and (7,8) are worth somewhere between 1 and 2 points above average. These can be derived from the tables noted above. All other combinations are at or below average. Of particular note is that other than (5,5), throwing a pair to your crib rarely yields any benefits.
Discarding to your opponents crib follows similarly from the above. I typically think in terms of how many ways a pair of cards might be combined to score -- for instance, the safest throws to an opponents crib is one mid-card and one ten card that can't make a run, as they can never be combined to score.
Utility for pegging. Keeping a range of different cards gives more options for pegging, both offensively and defensively. Hands with many 5 or 10 cards can easily be exploited by a cunning opponent!
Finally, skilled humans make all of the above decisions in light of the current game score and take more risks when they are at a disadvantage and play more conservatively when they are at an advantage.
One of the key strategic decisions in Cribbage is discarding. You are dealt 6 cards and must choose 4 to keep, the other two go to the Crib (either yours or your opponents). A card is cut after the discarding decision is made, so one must account for uncertainty in that card in the decision-making.
The full game state relevant for discarding is the 6 cards, player score, opponent score, and who has the upcoming crib.
Skilled humans typically weigh a couple of different things when discarding:
(5,5)is worth 4 points above average,(5, Any Ten card)is worth 2 points above average,(5, Any other card)is worth one point above average (though(5,6)and(5,4)are worth more), and(2,3)and(7,8)are worth somewhere between 1 and 2 points above average. These can be derived from the tables noted above. All other combinations are at or below average. Of particular note is that other than(5,5), throwing a pair to your crib rarely yields any benefits.