In poker, a full house or full boat
made up of cards of very low rank. The low valued cards are themselves referred to as rags, but when they become part of a full boat, they suddenly become a very strong hand. A rag boat generally occurs when a player finds himself involuntarily playing a very bad hand, or chooses to play them with the knowledge that it's a very bad gamble. Therefore, a rag boat is mostly luck. A rag boat also occurs in the sense of a hand that would have been made if such a bad gamble had been taken, but wasn't.
Player 1: "If only I'd played that three-eight, I would've ended up with a full boat and won."
Player 2: "It was better to fold, you'll go broke hoping for a rag boat."