Bidding box for home-played games. Use of bidding boxes has several advantages over oral bidding: it reduces noise in the room, prevents bidding being overheard at neighboring tables, allows easier review of the auction, and reduces the opportunity to pass unauthorized information to one's partner (intentionally or not) by the manner and intonation in which one makes one's bid. A bidding box is typically a plastic box with two slots, each containing a set of bidding cards. One slot contains 35 cards with symbols of bids (5 denominations—clubs (), diamonds (), hearts (), spades (), and notrump (NT)—in seven levels of bidding,
Common value auction case, where there is always a SBNE (see first-price sealed-bid auction). The following example is based on. There are two bidders participating in a second-price sealed-bid auction for an object. Each bidder "i" receives signal "si"; the signals are independent and have continuous uniform distribution on [0,1]. The valuations are: where formula_5 are constants (formula_6 means private values; formula_7 means common values). Here, there is a unique SBNE in which each player bids: This result is in contrast to the private-value case, where in SBNE each player truthfully bids his value (see second-price sealed-bid auction). This example is suggested as