How Cue Bidding Works
When you've agreed a trump suit and you're already commited to game, bidding a new suit is a cue bid showing an ace, king, singleton or void in that suit and showing an interest in slam.
Cue Bidding To Avoid A Bad Slam
1♠ from North, I bid 2♥. North bids 3♥ and my mind is turning towards slam. What's the right way to explore slam here?
I'm not going to say right way! What are the different ways we might explore slam here? I could give up and just bid 4♥ but I feel I'm too strong for that. I could bid 6♥ straight away but maybe that's a little bit pushy. I could ask for aces but that might not solve my problem.
For example, if I ask for aces and North's got one ace, that's great, it must be the ♦A. But even if North has no aces, we still might make a slam. Perhaps North's got a singleton diamond, perhaps North's got ♦K.
Showing First or Second Round Control
As soon as our side has bid and supported a suit, we know what the trump suit's going to be. I've bid 2♥ and north has bid 3♥. I know hearts are going to be trumps. North knows hearts are going to be trumps. So if I bid a new suit now, rather than ask for aces, I can show my aces.
When I bid 3♠, North knows that I've got first or second round control in spades - either the ♠A, ♠K, a singleton or void.
North Continues Cue Bidding
North bids 4♣. Great! So North has either got first or second round control in clubs. I've got the ♣A. So North might have the KC. That would be second round control. North might have a void in clubs or a singleton club. All of that's great.
Now what? Well, I've got a bit of a problem in the diamond suit because I don't have first or second round control in the diamond suit. That's a potential disaster if we bid slam. So I'm going to bid 4♥. And when I bid four hearts, North will know that I do not have first or second round control in diamonds because if I did, I would have bid 4♦.
Stop In Game With Two Losers
So I bid 4♥ and North passes. Why did North pass? North also has a problem in the diamond suit.
So let's just look at that auction again. When I didn't bid 4♦ or 6♥, when I just stopped in game, North realised that I had at least two losers in the diamond suit. North also had two losers in the diamond suit so we stop in 4♥. We don't want to be in six hearts missing the ♦A and ♦K.
Cue Bidding To Get To A Good Slam
My hand is exactly the same as it was on the first example. So I'm just going to bid 2♥, same as before, 3♥, 3♠, 4♣. All the same.
We've got a heart fit. I've shown first or second round control in spades. North has shown first or second round control in clubs.
I have a problem in the diamond suit. So I stop in 4♥. But north bids 4♠.
Well, well, well. So north knows that I've got a problem in the diamond suit. But north is still interested in the slam. North must have either first or second round control in diamonds.
4♠. Well, that must be second round control in spades. It must be the ♠K, because I've got the ♠A. North's showing second round control. North bid 1♠ so he can't be void in spades. It can't be a singleton spade. So North's got the king of spades.
Now I could do various things. I could keep cue bidding or I could ask for aces now if I wanted to. But I'm just going to simply bid 6♥.
This Time We Can Make 6♥
And North's got that singleton diamond. That's exactly what we needed.
We got to slam without asking for aces. We were able to highlight that diamond, or I was able to highlight that diamond problem. And we get to 6♥ this time.