Five-suit bridge called "Castle Bridge", in which the fifth suit of Castles looked like a Rook chess piece and was colored green. This pack reused the diamond courts for the new suit. The manual that came with this deck did not use Marseille's rules but Ammiel F. Decker's 1933 rules. Ultimately, the complexity of adding a new suit to the game led to it falling out of popularity by the summer of 1938. The rules are similar to regular contract bridge but the new fifth suit is ranked higher than spades but lower than no-trump in bidding. Decks usually came with one
Winner's curse to account for the winner's curse when bidding (an outcome that, according to the revenue equivalence theorem, need never occur). In a common value auction, the auctioned item is of roughly equal value to all bidders, but the bidders don't know the item's market value when they bid. Each player independently estimates the value of the item before bidding. The winner of an auction is the bidder who submits the highest bid. Since the auctioned item is worth roughly the same to all bidders, they are distinguished only by their respective estimates of the market value. The winner, then, is