A control-showing cue-bid is a form of slam try, which ensures that the opponents cannot cash quick tricks off the top of a suit.

Convention Edit

After a suit has been agreed upon, a new suit bid at the cheapest level above 3NT[1], or when the auction is game forcing, is a control-showing cue-bid and is a slam try. It shows a first-round control[2] in the bid suit: either an ace or a void. If the suit is cue-bid again, it shows second-round control: a king, a singleton or a void. Control showing bids are a key aspect of slow approach.

Controls are bid from the lowest available suit up, while bypassing a suit denies control in that suit. An example:

Opener Responder
1 21
32 43
44 55
  1. agreeing the suit
  2. spade control, slam try
  3. diamond control, denies club control
  4. cuebidding the second time shows a second-round control
  5. an attempt to sign off

Follow-ups Edit

Once cuebidding has started, the auction can be stopped only at the agreed trump suit:

  • A non-agreed suit bid is a control-showing cue-bid
  • A trump suit bid is an attempt to sign off, showing either no more controls or no further interest. Partner can continue to cue-bid to insist the slam try.
  • 4NT is Blackwood.
  • A non-jump 5NT asks for the top honours.
  • Jumping to 5NT is grand slam force.


  1. If the agreed suit is , then 3 is the lowest available control-showing cue-bid.
  2. Some partnerships choose not to distinguish between the first and second round controls, thus promising either one by cue-bidding the suit.