Quick summary

Controls for slams are:

Only show slam controls after suit agreement. How?

Partner then does same

Use cue-bidding when you have

Can't use with NT contracts!

After cue bidding has started, all side suit bids are cue bids.

After 1st round controls have all had a chance to be shown, can repeat with 2nd round controls

Bidding Trumps means "enough".

Bidding NT means

More modern versions exist: on the first cue-bid below 4NT they show either 1st or 2nd round control, with equal probability.


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Bridge Venue

Example Deal
spade 3
heart K 8 5 4
diamond A K J 10 9 6
club K 5
Example Deal
You: North
Dealer: East
Vuln: all

Sorry partner, we should have been in a Slam…
Go to quiz (& full page) of deal # 126032

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p ???

#2+<-- click the + for explanation of relevant Bidding Techniques

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«  0168  »

Slams: Cue-bidding for controls

"Partner, which Aces, Kings and voids do you have ?"

Cue bidding will reveal the exact location of "controls":

  • A first round control is an Ace or a void;
  • A second round control is a King or a singleton

When you're contemplating a Slam in a suit, it may not be enough to know that your partner has "one" Ace - you might need to know which one. In this case use Cue bidding. (Oh, and since we are talking only about suit slams, a void can control a suit just as well as an Ace).

Only do it if you have already explicitly agreed the trump suit.

A Cue bid is a dual purpose bid - it both shows a control and requests help in finding missing controls.


Say for example you hold KQx in one suit and Qxxx in another suit, and a void in a third suit. None of these is the agreed trump suit. If partner holds the Ace in the first suit (where you have KQx), you could still be wide open to attack in the suit where you have Qxxx. So the contract could go down inside the first couple of tricks. However, if your partner holds the Ace or King (or a void or singleton) in the exact suit with Qxxx, then you still have a chance for a small slam. But an Ace in the suit where you have a void is no use.

In other words, don't use Blackwood, use Cue bidding, because you need to know which suit your partner may control.

When is Cue bidding useful?

When bidding for a suit slam, you often need to know in which suit a particular Ace or void lies. For example:

  • You have weak suits:  Suits with 2 or more cards must have an Ace or King. Otherwise you might lose 2 tricks straight off. Use Cue bidding when you need to know whether your partner has control opposite any specific weak suit of yours.
  • You have void suits:  Aces and voids are powerful. It's a waste though if they are directly opposite each other in the same suit. 
  • You are a bit too weak for a 4NT Blackwood enquiry.
  • If the response might go too high for Blackwood:  For instance, if club are agreed as trumps, and you need 2 key cards from partner for slam, then a 5diamond Blackwood reply showing only 1 key card is a disaster. You are forced to bid 6club. In other words, you need to hold more key cards yourself to use Blackwood if the agreed suit is club. It can also be a problem if it's diamond. Use Cue bidding and the Losing Trick Count.

When to avoid Cue bidding:

  • If responder has shown a minimal holding, then avoid Cue bidding if it would take the bidding beyond a game contract.
  • If a Slam is not possible.
  • When your partner doesn't understand it.
  • When you don't understand it.
  • When knowing specifically how many Aces / Keycards you have is sufficient - just use Blackwood /RKCB.
  • With No Trumps! That would be insane. The last thing you want in NT is a void.

Two types of Cue bidding

Our favourite type is the simpler version

This is the one that simply establishes whether all 4 suits have some degree of control, either first round or second round. If there's any suit that's uncontrolled - then you know that it's generally wise to reduce your ambitions to a game only bid. After all, your enemy can run off two immediate tricks in that suit, and there goes your Slam.

If you've got all 4 controlled to some level, that's step one. But if they are only 2nd round controls (King or singleton) - you could lose one trick in every suit, unless of course you can see 4 Aces or voids in your own hand. Step two is to switch to Blackwood, to ask your partner about the quantity Aces he has to make up for the quantity of Aces or voids that you can't see in your hand. If the answer comes back that your team's only missing one of the 5 keycards (the 4 Aces and the king of trumps), then you have all 4 suits under control, and no more than one trick winner missing. Slam on.

If the answer's that 2 are missing, then you can either back-off to game, or try to work out from the bidding if the missing one is opposite your shortage.

The more traditional and more complicated version starts by asking about first round controls. Then, as soon as any suit is either mentioned or passed over at the second opportunity, then possession of the "second round" control is established.

Making a Cue bid - traditional "first then second round" control

After trumps have been agreed, a bid of another suit below the 4NT level is a Cue bid, showing first round control in that suit (Ace or void) and suggests that you're interested in a slam. E.g. 1spade-3spade-4club.

You should first bid the lowest suit in which you hold a first round control. Missing out a suit indicates that no first round control is held in that suit. Partner will then go up the suit ranks and show his or her lowest-ranked first round control.

After first round controls have been shown for all suits, if you wish, you may then use Cue bidding to establish second round controls, namely kings or singletons.  If no more controls are held, or you wish to sign off ("let's stop here"), bid the agreed trump suit.

The process continues until one of the partners has sufficient information to make the contract decision.

The meaning of "No Trumps" in Cue bidding. After Cue bidding has started, the more common meaning of 4NT or 5NT is indeed for Blackwood, asking for Key cards.

It might be possible to deduce that you DO have the Ace and King of Trumps, but if not, and you need to find out then you can use Blackwood, provided the bidding hasn't gone beyond 4NT.

(Note that some cue-bidders use NT bids to describe their trump suit controls, but this should only be done if you and partner have agreed beforehand).

The meaning of "Trumps". Do not Cue-bid in trumps if trying to give information about controls in trumps, because trumps are used to sign off. Trumps means "Enough, from my point of view. Continue bidding only if you have a reason I don't know about".

The switch from first round to second round. If the bidding conversation about first round controls has not allowed the two of you to report the facts about a particular suit, then the first round continues until it has given you that opportunity. The very next Cue bid is a second round control.

Suit agreement

Suit agreement can be explicit, e.g.

1heart -3heart-3diamond is a Cue bid asserting control in Diamonds.

Or it can be implicit, e.g.

1NT-3spade-4diamond is not suggesting diamonds as an alternative suit. It's announcing agreement to spades as trumps and asserting 1st round control in diamonds. If Opener had not liked the spades, he would have returned to NT.   

(Beware above: when the trumps are a minor suit, some people insist that the first Cuebid is higher than 3NT).

Confusing with Trial bids ?

A bid of a new suit after minor trumps have been agreed is a Cue-bid. E.g. 1club-3club-3diamond is a Cue bid asserting control in Diamonds. Unless it's a Trial bid! (minor suit agreement, looking for support in an attempt to get to game in NT).

To avoid confusion, first assume you partner is aiming for 3NT. If he carries on after 3NT, then it must be a Cue-bid aiming for Slam in the established suit.
1club-3club-3diamond-3NT-End.  A successful minor trial bid, asserting stopper in diamonds, and asking partner to plug the other two.
1club-3club-3diamond-3NT-4heart-4spade-6club.  You have controls in diamondheart, partner has controls in spade. End up in Slam in Clubs

Confusing with Game try ?

A bid of a new suit after Major trumps have been agreed is a Cue-bid. E.g. 1heart-2heart-3diamond is a Cue bid asserting control in Diamonds. Unless it's a Game Try ! (Major suit agreement, looking for support in a second suit in an attempt to get to game in the Major).

To avoid confusion, first assume you partner is aiming for 3 or 4 in the Major with help in one suit. If he carries on after your reply, then it must be a Cue bid aiming for Slam in the established suit.
1heart-2heart-3diamond-4heart-End.  A successful Game try, asking for help in diamonds.
1heart-2heart-3diamond-3heart-End.  A failed Game try, asking for help in diamonds.
1heart-2heart-3diamond-3spade-4club-4diamond-6heart. You have controls indiamondclub, partner has controls in spade and second round in diamond. End up in Slam in Hearts.
1heart-3heart-3spade- etc etc   Must be a Cue bid, not a Game try, because the bidding cannot stop below game..

Confusing with Splinters ?

A double jump to a new suit after trumps have been agreed is a Splinter-bid, e.g. 1heart-3spade is a Splinter showing a singleton or void in Spades. 1club-2club-4diamond is a Splinter showing a singleton or void in diamonds. Partner of the splinter bidder will then typically bid game or use Cue-bids to investigate a slam.

Confusing with 16HCP alternative long suit ?

1heart-2spade is a single jump shift showing 16+ HCP and a long 6-card Spade suit.


If a Cue bid is doubled, e.g. as a lead directing double by the enemy, then redouble shows second round control of that suit. To pass is neutral, conveying some interest.

Dangers of Cue bidding ?

It can tell the enemy where your weaknesses are, and also give them opportunities to make 'lead directing doubles'. Click the link for an excellent example of both lead direction and Cue bidding.

Some other guidelines and alternative Cue techniques

  1. If responder has shown a minimal holding, then avoid Cue bidding if it takes the contract beyond game.
  2. Below game, make a Cue Bid only if slam appears possible
  3. To Cue above five of the trump suit is a try for a Grand Slam.

You should discuss and agree or disagree the following with partner first. If you haven't, don't use them:

  1. On occasions, especially if you are known to be weak, it is necessary to Cue a second round control before a first round control in that suit has been shown or denied.
  2. Cue bid unbid suits first (suits which so far remain unbid by you and your partner)
  3. Plan your Cue bids. The cheapest Cue bid may not be the best bid, as it may cause your next Cue bid to be higher than if you reversed the order. i.e., 4club-4x-4spade rather than 3spade-4x-5club.
  4. Avoid Cue bidding singletons or voids in a suit bid naturally by your partner.

Example bidding

168. Cue bidding for controls
West  East
1heart 12-19 opening hand, 6 or 7 losers 2 NT Jacoby 2NT: 7-loser 4-card Major support to game with Slam interest, no shortages
4club Strong (16-19, 6-losers), 4-card 2nd suit in club (3heart if 16-19 but no 2nd suit) 4diamond 1st round control of diamond
4spade 1st round control of spade 4NT 1st round control of trumps (heart). (Beware! This is unusual, and only be partner agreement. 4NT normally means "OK, Blackwood" - tell me how many Key cards you've got).
5club 1st round control of club
5heart No 2nd round control of diamond. Sign off in trumps (heart).
Sign off unless you have something good - I'm worried about missing Ks in clubdiamondspade
6club No 2nd round control of spade
2nd round control of club
6heart Sign off in small Slam. We have a 50% chance. No point going any further with 2 Kings likely to be missing (we have 28-31 HCP)

Deal 49277
S A Q J W     E  S 6 4
H Q 10 8 4 H A K J 9 7 5
D 10 8 D A J 5
C A K 10 8 C J 9

The 5club bid from West in the example above shows a first round control in Clubs, not a second round control, because up to this point there has been no opportunity to show Club controls. The very next Cue bid from East will then be a second round control, because there has been a chance to show all the other suits. West's bid of 6club is then a second round control.

Deal 1

spade J 4
heart A K 10 8 7
diamond Q 5
club A K 7 2
  1heart Pass 2spade Pass
  3club 3heart
  ? ?
 ? ?
 ? ?

West opened 1heart and East responded 2spade (game force, good spades and 16+ points). West rebid 3club and East bid 3heart. A slam is very likely, but how should the bidding proceed?


<---- Click the "+" for the Answer

Deal 2

spade A K Q 10 3
diamond K Q J 3 2
club A 4 2
  2spade Pass 3spade Pass
  4club 4diamond
  4heart ?
 ? ?
 ? ?

West opened 2spade. East raised to 3spade, showing at least three spades, with one or more aces and 8+HCP. 3spade is forcing to game and stronger than bidding 4spade directly. West Cue bid 4club, East Cue bid 4diamond, so West could cue bid 4heart showing control of Hearts. How should the bidding carry on ?


<---- Click the "+" for the Answer



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