Back in the 1930s, Ely and Josephine Culbertson introduced their new Grand Slam Force (GSF) convention, a 5NT bid that asked partner to bid seven with two of the top three trump honors. This gadget was quickly accepted as indispensable and it’s been a mainstay of standard bridge bidding ever since.
Although the GSF is still “on the card”, it’s become something of a dinosaur in modern systems. Trump honors are now easily located with Keycard and Exclusion Blackwood, leaving 5NT available for other uses.
Today, the expert view is that 5NT is the GSF only when it’s a jump and there’s just one possible trump suit. The suit is usually a major that’s been raised, but it can also be one where the 5NT bidder’s fit is strongly implied (after partner opens a preempt, for example).
In other situations, 5NT is played as a quantitative notrump raise, a specialized cuebid or a request for partner to choose a small slam. Many of these ideas are now widely accepted as “expert standard”, but they aren’t just for experts. If you have an experienced or studious partner, it’s likely that he’ll assume the modern meanings, so you’ll want to be familiar with them, too.
What do you believe your 5NT bids should mean in the auctions below? And, more important, how do you expect your partner to interpret them?
LHO Partner RHO You
(1)
1NT Pass
2D
Pass 2H Pass
5NT
(2) 1NT Pass
2C
Pass 2H Pass
5NT
(3) 1D
1S 2H 4S 5NT
There should be little confusion about (1), which is a standard “pick-a-slam” auction. Your transfer-then-5NT sequence shows exactly five hearts and the strength for 6H or 6NT. If you had responded a direct 5NT, it would be a quantitative raise inviting 7NT.
(2) might be read as a trump ask because the original GSF was applied to the last-bid suit if it was a natural call. Although partner’s 2H showed hearts, this 5NT bid should still be treated as a search for a small slam. Since it’s possible you have a 4-4 spade fit, opener’s choices are 6S and 6NT.
The Culbertsons would have defined (3) as GSF for partner’s hearts, but the choice-of-slams interpretation is preferred here, too. This meaning takes precedence when there are two or more possible strains. The possibilities depend on the auction, but in general, they include any suit that was bid naturally, even if you haven’t supported. Notrump may be in the picture, too, if it was bid naturally.
Here, your 5NT suggests extra length in your suit and support for partner’s
suit, but doubt about which slam is better. You might hold
♠Void
♥964
♦AKQ982 ♣AK74
Partner will usually bid six of the suit he prefers. Although your 5NT shows
interest only in a small slam, he also has the option of bidding seven if he has
undisclosed strength.
In some situations, partner may even be able to offer you a choice. Over your
5NT, he can suggest yet another strain by bidding a natural 6C with a hand such
as
♠J64
♥AQJ72
♦Void ♣QJ1032
The choice-of-slams treatment is trending “up”, but its popularity doesn’t necessarily make it standard. If you haven’t discussed these auctions, you’ll want to think carefully about your partner’s bidding knowledge and style before you try a pick-a-slam 5NT. If he reads it as the Grand Slam Force and jumps to seven, he won’t have much sympathy for the excuse “But it’s expert standard!”
© 2011 Karen Walker