In "precision" or "exact-prediction" games, all players choose their winning condition independently: to win precisely a predicted number of tricks (Oh Hell) or card points (Differenzler). Each player's bid stands (in partnership games the partners' bids are often combined), and each player or partnership then tries to take exactly the number of tricks or points they bid, and are rewarded or penalized for doing so independently of anyone else's success or failure in meeting their bid. This type of game began to mature in the 20th century. Other games generally falling into the exact-prediction category are Spades and Ninety-Nine.