A method is presented that determines optimum bids in a competitive-bidding situation where each competitor submits one closed bid. The number of bidders may be large or may be unknown. This method makes use of the previous “bidding patterns” of all possible opposition bidders and in the case where the bidding is on contracts, the estimated probability distribution of the cost of fulfilling the contract. The case where a number of bids are to be submitted simultaneously is also discussed.