The undertaking by declarer to win a number of tricks, in the denomination named, specified by the final bid of the auction. The number of tricks is six more then the bid, ie. you need ten tricks to make 4♠. A defender may double the contract, in which case a member of the declaring side may redouble. The lowest contract is 1♣ and the highest contract is 7NT redoubled.
Did you know there is a new free resource from BMB – The Bridge Gazette?
Click here to take a look