The advance cuebid is, simply stated, a cuebid
of a first round control. However, the difference in the bidding sequence is the
fact, that only one partner knows the suit agreed upon. Since this is the case, the
partner left in the dark does not know exactly what his partner is up to, and this
can lead to a certain ambiguity.
The partner, who cuebids, is keeping the auction
alive and hopes that his partner can distinguish during the bidding process between
a normal raise and a raise based on controls, plus a certain distributional fit which
could make slam an excellent possibility, if his partner has a certain favorable
distribution.
First of all, North has no idea of the meaning of the 4 Clubs bid of South. South is cuebidding, but North does not yet know this. South is considering a possible slam, and after the jump raise in Spades, South realizes that North could have a solid Spade suit, and if North has a control in Diamonds plus the King of Hearts, then a slam in Spades is an excellent contract. The rebid by South of 4 Clubs is an advance cuebid, keeping the bidding alive even though North is still in the dark. North is first of all visualizing that South is holding a 5-card suit in Hearts and a 4-card suit in Clubs, a two-suiter.
North naturally assumes a two-suited hand by South, but cuebids first by keeping the bidding process alive by looking for a feature in Diamonds. This is the primary objective for North. If North has a control feature in Diamonds, then North bids 4 Diamonds. If North does not have a control feature in Diamonds, but does have the King of Hearts, then North bids 4 Hearts. In any case, North will not rebid his Spades. It is also possible that North cuebids a control feature in Clubs.
The nature of the Advance Cuebid also allows the use of the cuebid even after a jump shift by the opener. An example follows:
The holding of South indicates strongly a possible slam in Diamonds. Instead of simply raising the Diamond bid of North, South advance cuebids his Ace of Clubs before the trump suit has been agreed upon by both of the partners. Only one partner has the knowledge of the direction of the bidding and which contract will be the final contract. Any partnership using the Advance Cuebid as part of their Partnership Agreement must settle on the fact that the agreed trump suit is only implied.
In the above example, North will rebid any first round control in Hearts and/or Spades, bypassing Diamonds, and the auction will still remain on the four level. A game contract is definite, and the exploration for a slam is now underway at a safe level. Whatever North bids, the auction will be kept alive until the final contract has been reached.
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.