Calls made during the auction phase of a contract bridge game convey information about the player's card holdings. Calls may be "natural" (that is, are based on a holding of the suit bid, or a balanced distribution in the case of a notrump bid) or "artificial" (show a feature unrelated to the named denomination). A bridge convention is an agreement about an artificial call or a set of related artificial calls.Verlag BoD NorderstedtISBN 9783744817349
