Slam bidding is a vast subject, so this topic merely gives a cursory introduction to the subject suitable for beginners.

There are two basic elements to bidding and subsequently making a good slam.

  1. Sufficient Strength. The two hands must combine to be able to produce twelve (small slam) or thirteen (grand slam) tricks. This roughly equates to 33+ and 36+ points for the two types of slam including distribution points in a suit contract. These ranges are merely guidelines and are subject to…..

  1. Controls. It’s no good having twelve tricks available if the defence cash the first two tricks. In simple terms this means that a small slam requires a minimum of three aces (assuming no voids), and a grand slam requires all four aces.

Of the two elements, strength is by far the most important. Declarer may survive after a luck opening lead if the ‘control’ position is shaky, but if the strength is missing the slam will invariably fail.

Strength can be assessed in the general bidding approach (as shown in the examples), and for beginners, the controls can be reasonably assessed by way of a convention called ‘Blackwood’.

Blackwood is a convention whereby a bid of 4NT asks partner to define the number of aces he has (more sophisticated versions are able to assist in defining which aces – but these are beyond the scope of the beginner).

(An exception is where 4NT is bid immediately after a1NT or 2NT opener – this will be left for the moment).

In response, partner bids:

5♣ with 0 or 4 aces (partner can surely work out which)

5 with 1 ace

5 with 2 aces

5♠ with 3 aces

Furthermore, if the original bidder is interested in investigating the possibility of a grand slam, he can then bid 5NT which asks partner to define the number of kings that he has (this bid must only be used if the original 4NT bid has ascertained that you have all the aces between you).

So the logical approach to slam bidding is:

- the partnership finds a fit (or possibly no-trumps if there is no fit)

- one player realises that the total strength of the combined hands is in the slam region

- check the necessary first round controls (aces)

- check the necessary second round controls (kings) if interested in a grand slam.

Exercises (North the opening bidder):

a)♠ KJ98b)♠ QJ98c)♠ AQ76d)♠ AK654e)♠ AQ10732

AKQ65 AKQ65 93 AK83 82


♣ Q65♣ Q43♣ AK863♣ 96♣ A43

f)♠ AK10732g)♠ KJ953h)♠ 87

J2 AK87 QJ742

QJ 7 K732

♣ KJ3♣ QJ10♣ A6

a)   1

2♠     - 16+ points, probable 6 card good suit.

4NT  - sufficient points,- Blackwood ask for aces (with the intention of bidding a spade slam)

5♠     - 3 aces (nothing to do with spades as a suit)

5NT  - Blackwood ask for kings

6♣     - no kings

6♠     - one king missing, so settle for the small slam

b)     - as (a) but after 4NT, South bids 5 showing only one ace. North now knows there are two aces missing, so merely bids 5♠

c)   1♣


3♠     - showing at least 16 points with spade support

4NT  - Blackwood for aces

5     - two aces

6♠     - most likely ace to be missing is A (North has opened 1♣), so try for the slam (but by no means guaranteed)

d)   1♠


4NT  - good heart support, partner has shown 9+ points so worth a try. It does depend upon partner having an ace (of clubs) – you wouldn’t risk it without a club stop.

5     - one ace

6     - enough