(Okay, so the bridge term of the week doesn't actually come out every single week.  I've got a job, k?)

Rueful Rabbit (noun): a bridge player whose worry-filled and mistake-plagued play is nonetheless successful through incredible good luck at the table

Origin: The Rueful Rabbit is a character in series of bridge books by Victor Mollo called "Bridge in the Menagerie".  Mollo is considered the most entertaining and influential writer on the subject of contract bridge - now there's something to put on your tombstone.  The books describe bridge games played at "The Griffin Club" among a group of characters who are all named after the animal that best characterizes their personalities and styles at the bridge table.

The Rueful Rabbit was a timid player who didn't understand the game, but succeeded entirely through blind luck.  Even when he dropped cards on the table because his hands were shaking so badly, the cards would end up being the correct one to play.  Some other characters in this game were:

Secretary Bird - the player who enforces every rule to the letter, always to his own detriment
Hideous Hog - the best player, he also likes to humiliate lesser players
Papa the Greek - a good but vain player, who considers himself better than the Hog despite always losing to him
Sassy Suzi - a decent player whose trash talking far outstrips her ability

Wait, that last one is a character in my upcoming book on bridge.