I have been playing Pinochle since the 1960's. It is a fairly complicated card game to play. Basically, 2 Euchre decks are combined so there are two of each card--the 9, 10, Jack, Queen, King, and Ace of all four suits, for 48 cards per deck. Deal 12 cards to 2 sets of partners, then bid, then pass 3 cards to your partner, then meld, then play hand to take tricks with "count". Count cards are A, 10, K. Meld + count on tricks must meet or exceed bid. Simple!
Meld is made of 'marriages' (Q,K of same suit), 'arounds' (J,Q,K, or A of each suit), 'runs' (J,Q,K.10, and A of same suit), ''Pinochle" (J of Diamonds and Q of Spades), and the 9s of trump are always meld. Better meld is a double Pinochle, doubles around, and double run. The double run is the most points a player can meld. I've been playing Pinochle for almost 50 years and have never seen a hand with a double run until now--I've only seen doubles around twice in that same have a century.
