Five-card majors for offensive purposes. However, if the trump cards break 4-1 or 1-4, then drawing trump will result in no trumps left for offensive purposes. The value of five-card majors can be understood then on two levels: But five-card majors have several drawbacks: Both partners must agree to follow the five-card major bidding treatment on their opening bid. Opener must have at least five cards in hearts or spades to start the bidding with that suit. Responder is expected to show support with three-card support, indicating an eight-card fit. With only four cards in a major suit, the opening bidder is
Jump bidding Jump bidding In auction theory, jump bidding is the practice of increasing the current price in an English auction, substantially more than the minimal allowed amount. At first glance, jump bidding seems irrational. Apparently, in an English auction, it is a dominant strategy for each buyer whose price is above the displayed price, to always bid the minimal allowed increment (e.g. one cent) above the displayed price. By bidding higher, the bidder gives up the opportunity to win the item at a lower price. However, in practice buyers increase the displayed price much more than the minimal allowed increment. Often,