Sometimes you need to know which aces or voids partner holds, rather than how many (Blackwood). When it comes to looking for specific controls, including singletons and voids, a different approach is required. Now you need cue-bidding, which tells you about specific controls.
When is it a cuebid and when it is simply a new suit?
• When the partnership is already committed to at least game, and has found an obvious fit, the bid of a suit in which the partnership can’t want to play is a cuebid, showing interest in reaching a slam contract
• With a choice of cuebids, make the most economical (cheapest) cuebid first.
Cuebidding a Void
In trumps, a void can be as effective as an ace since it controls the first round of a suit. Cuebid a void as though it were an ace. Either player may cuebid a void. e.g. you hold: ♠KQJ7642 ♥AJ ♦62 ♣AQ partner holds ♠AT83 ♥72 ♦AK85 ♣973
You open 1♠ and partner bids 3♠. You are holding the ♣A, so show it by bidding 4♣. This shows first round control in clubs. If partner now bid 4♦ it would show first round control of diamonds.
Once the spade fit has been agreed, South suggests going beyond game by showing first round control of clubs. North cooperates by showing first round diamond control, which is good news to South’s ears. There’s no need to keep cueing as South has the ♥A, so they Blackwood instead to ask for controls in the trump suit.
One of the rules of cue bidding is that you don’t show trump suit controls when cueing. Bidding the trump suit allows you to get out of the cueing process if you have nothing more to show. Or, use Blackwood if you need to know about trump controls.
Second Round Controls
Cuebidding is initially used to show first-round controls- aces and voids- but can be used to show other controls as well. A King is a second-round control since it offers protection against the defenders taking the second trick in the suit. A singleton has the same effect as a king: the opponents may be able to take the ace in that suit, but they can’t take a second trick.
Generally aces or voids are shown first in cuebidding sequences. If there are still some questions as to the best contract, the partnership continues by showing kings or singletons.