 For storage purposes, the boxes usually have either a covered compartment at the bottom to store the bidding cards or a cover which is placed over the bidding cards attaching to the box base.A bridge auction consists of a sequence of "calls" (a bid, pass, double, or redouble) made by each player in turn, until it is concluded by a sequence of three consecutive passes.With the transition from auction bridge to modern contract bridge, the bidding has become more complex, and conventional auctions often last through several rounds of bidding.