41 Slam bidding

4NT was not designed for getting into a slam, it was designed for staying out of one. A slam is just a game with overtricks, and primarily you need to feel that the overtricks could well be there. 4NT is just a safety measure.

If your partner has bid NT (any number) and your point count looks good enough, it is a matter of simple arithmetic - add your points to hers and see. You are looking for a total of 33 points between you. (This figure means that you cannot be missing two aces.) If you can see 33 even if her point count is minimum, bid 6NT immediately. If you cannot see 33 even if her point count is maximum, pass. But if the max would produce 33, then 4NT says “Go 6NT if you have a maximum, pass with a minimum, or 5NT with the middle figure.”

4NT over any NT from partner is NOT asking for aces: you could have all four aces and still be short of 33.

4NT over an agreed suit (or after the last suit just bid if no agreement yet) depends on what convention you are playing, the choice is yours, and it must be agreed with partner or trouble looms:

1. Gerber  This isn’t 4NT of course, it’s 4C. If you are playing this, I wish you weren’t; it has been called the biggest single cause of confusion in bridge, because it rules out 4C for other purposes, and there are several of these, not least as a raise of partner’s club bid. Do consider Blackwood at least. If you like Gerber because it keeps the bidding low, why are you seeking a slam if you even fear the 5 level?
2. Blackwood This 4NT bid means “How many aces, partner?” And the replies are: 5C = 0 or 4,  5D = 1, 5H = 2, 5S = 3.  Note that 0 or 4! Simple to remember.
3. Roman Keycard Blackwood (RKCB) is adopted by the more progressive players and 4NT means “How many keycards, partner?” There are five keycards: the four aces and the king of trumps, and the replies are: 5C = 0 or 3,  5D = 1 or 4, 5H = 2 and no queen, 5S = 2 + Q.  The queen of trumps is not a keycard, it’s an extra feature that you may be lucky enough to show. There are more options in the full version of RKCB but this will do for now.

How to use 4NT

Only use it if you need to. Only use it if you can cope with any response by partner. Avoid it if you have a void: what if partner has an ace there? Experienced players should learn how to cue-bid their aces before trying 4NT.

Splinter Bids

And here’s another useful aid to slam bidding. Your partner opens a major suit, say 1S. What do the following responses mean? 2D, 3D, 4D?

You should have no trouble identifying the first two – normal change of suit showing 8-10 pts, and jump takeout forcing to game showing 16+ pts. But a double jump? That’s a splinter bid, and it carries three messages: I guarantee 4S, I have mild slam interest, and I have a singleton or void in diamonds. This responding hand should not only have the singleton but good actual points as well, say about 12. Partner can now take suitable action: 4S shows no slam interest, so we go no further, but 4NT is often the next move. Of course it does not agree diamonds!