Its distinguishing motive is presence of a "vice" menace in one suit, where one defender holds cards of equivalent rank which split the declarer's pair of cards in front of him, where his partner has a winner in the suit.
A key feature of this game is the presence of a "vice" threat in one suit. One defender holds cards of matching rank that divide the declarer's pair of cards facing them, while their partner possesses a winning card in that suit.