In 1936, Mr. Ely Culbertson devised the Grand Slam Force method of locating the top trump honors whenever the partnership had the opportunity to attempt a grand slam. This method was first published in The Bridge World, a publication started by Mr. Ely Culbertson, by his wife, Josephine Culbertson. This is the reason why this method is known as Josephine in some European countries.

After the partnership discovers that a slam is a certainty, and that a grand slam is a possibility, a bid of 5 No Trump by either partner is asking the responder to bid a grand slam if he holds two of the top three trump honors. It must be noted that this method does not apply if a bid of 5 No Trump is a natural No Trump raise, or if it is the natural bidding order of another convention included in the partnership agreement.

Any jump to 5 No Trump designates the last bid suit as the trump suit, provided the trump suit has not been specifically agreed upon in the continuing auction. The method is used to find out whether or not the other partner has at least one of the top three honors of the trump suit for a small slam, and two of the top three honors for a grand slam.

Used mainly for the Major suits, one method is to divide the responses into four steps. The First Step would show the weakest trump holding for the previous bidding showing 3 or 4 small trump cards without an honor. The Second Step would show at least 3 trump cards with the Queen of trump. The Third Step would show the Ace or King of trump (not the Ace and King) and at least 3 trump cards. The Fourth Step would show the Ace or King of trump (not the Ace and King) and additional length in the trump suit. If Spades is the agreed trump suit, then the Steps retain their original conceptual significance. If Hearts is the agreed trump suit, then the First Step and Second Step are combined. If Diamonds are the agreed trump suit, then the First Step and the Second Step are combined as is the Third Step and the Fourth Step.

Another method in partnership agreements is to sign off when holding inadequate trump support or trump support with no top honor. Responses at the Six Level are made inversely to the first method above, which means that a higher response indicates a weaker trump holding. In order to retain all four Steps to show the quality of control in the trump suit, even when a suit other than Spades has been agreed upon as the trump suit, this second method of Grand Slam Force allows the partnership to use Jumps to Five of the Suit above the agreed trump suit, instead of bidding 5 No Trump to initiate the Grand Slam Force.

There are a diversity of partnership agreements using different approaches to reaching a grand slam, and which incorporate different conventions and a combination of conventions. For example, the Grand Slam Force may also be used together with the Blackwood convention. The Romex System uses a bid of 5 No Trump also as a Grand Slam Force even after Blackwood has been initiated. Some partnerships use the Malowan Six Club Convention as the Grand Slam Force. After a conventional response to Blackwood, these partnerships bid 6 Clubs, with the proviso that Clubs is not an agreed trump suit. In the Schenken System, the partnership establishes a trump suit, and then cuebids First and possibly Second Round Controls before the level of 4 No Trump. Once 4 No Trump is reached and 4 No Trump is bid, then the partner rebids the trump suit with poor trump quality, rebids the lowest-ranking side suit with the King or Queen of the trump suit, the next ranking side suit with the Ace of trump, the highest-ranking side suit with two of the top three honors in the trump suit, and 5 No Trump with complete control of the trump suit.



If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.






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