How to Cue Bid First and Second Round Controls
Before jumping to Blackwood, partnerships use control cue bidding to show first-round (Aces or voids) and second-round (Kings or singletons) controls up the line.
When exploring a slam, simply knowing how many Aces your partnership holds isn't always enough. If the opponents hold the Ace and King of the same unbid suit, they will cash two quick tricks before you ever gain the lead! To prevent this, partnerships use Control Cue Bidding. After establishing a trump fit, bidding a new suit shows a control in that suit. First-round controls are Aces or voids; second-round controls are Kings or singletons.
Why control cue bidding works
Blackwood (4NT) only tells you how many key cards you have, not which ones. If you are missing two key cards, you might still bid a slam if the opponents cannot cash two tricks in the same suit.
By bidding controls "up the line" (bidding the cheapest available suit where you hold a control), you map out where your stoppers are. If neither partner cue bids Diamonds, it means the Diamond suit is "wide open." You can stop safely in game instead of charging into a doomed slam.
A worked example: Showing an Ace
Spades are agreed as trumps.
Your Hand (South):
♠ A K Q 9 4
♥ 8 3
♦ A 7 5
♣ K 6 4
The Auction:
- North: 1♠
- South: 3♠ (Game try/slam interest)
- North: 4♣ (Cue bid: Club control)
- South: 4♦ (Cue bid: Diamond control)
Caption: Partner's 4♣ bid says, "I have slam interest and the Ace (or void) of Clubs." You bid 4♦ to show your Diamond Ace. Notice that you bypassed Hearts—this explicitly denies holding the Ace or King of Hearts. If partner also lacks a Heart control, they will sign off in 4♠.
Four common mistakes
- Cue bidding before a trump suit has been firmly agreed upon (it sounds like you are just showing a new suit!).
- Skipping a suit where you have a control, leading partner to believe that suit is wide open.
- Cue bidding a singleton in partner's natural side suit (usually not helpful since partner wants to establish those cards, not see them ruffed).
- Rushing into 4NT when a slow cue-bidding sequence would have revealed two fast losers in an unbid suit.
When the rule does not apply
If you lack the points or shape to investigate a slam, do not initiate cue bids. A cue bid commits the partnership to at least the game level and strongly encourages slam exploration.
Key takeaways
- Used only after a trump fit is agreed.
- Bid up the line to show controls (Aces/Voids, then Kings/Singletons).
- Bypassing a suit denies a control in that suit.
- Prevents bidding slams with two fast losers in one suit.