Slam bidding tools

There are some tools to help players bid slams and to stay away when they do not have the appropriate cards.
Of primary importance are Aces held by the partnership.
To this end, Easley Blackwood devised the Blackwood convention in 1933.

Blackwood

A bid of 4NT asks partner for the number of aces; the responses:

5 C 0 or 4 aces
5 D 1 ace
5 H 2 aces
5 S 3 aces


Gerber

There were some situations where the 4NT bid was quantitative and could not be used for Blackwood.
In 1937 Johnny Gerber of Houston, Texas came up with a solution to this problem.
(Many players use the Gerber convention only if the first or last bid was No Trump)
In this system, a bid of 4C is used to ask for the number of Aces; the responses:

4 D 0 or 4 aces
4 H 1 ace
4 S 2 aces
4 N 3 aces

If the partnership has all the aces, a further bid of 5NT (or 5C) could be used to ask for kings.


Roman Key Card Blackwood

The Blackwood convention was enhanced to provide more information about the trump suit, in addition to the aces.
The enhanced system is called Roman Key Card Blackwood (RKCB).
Here, the trump King was counted as an ace and responses were modified to elicit information about the trump Queen.

5 C 0 or 3 Key Cards
5 D 1 or 4 Key Cards
5 H 2 (or 5) Key Cards but no Trump Queen
5 S 2 (or 5) Key Cards with Trump Queen

A 5NT call after this could ask for the number of Kings or the lowest suit with a King,
but it guarantees that the partnership holds all the Aces, the trump King and Queen.

After the reply of 5C or 5D, a relay could be used to determine if the partnership has the trump Queen.
For example, if the trump suit is Hearts and the reply to 4NT was 5C (0 or 3 Key Cards),
5D (the next available bid and not the trump suit) could be used to ask for the trump Queen.
The responses are:

5 H no Trump Queen
5 S Trump Queen and spade King
6 C Trump Queen and club King but no spade King
6 H Trump Queen but no Kings below trump suit

There are two interesting variations of RKCB:
1. Kickback - When the agreed suit is the minor jump to the suit above it to ask for Keycards e.g.
   1S-3D-4H; 4H is asking for Keycards with diamonds as the agreed suit.
   This gives room to respond and stop, if necessary, below the 6 level.
2. Double Keycard - If there are two agreed suits, count both the Kings as Keycards.


Intervention over RKCB

When there is intervention over RKCB there are two conventions which help the responder:
DOPI (short for Double 0(zero) Pass 1(one)) - used when the intervention is lower than the five level of the trump suit
DEPO (short for Double Even(0,2 or 4) Pass Odd(1,3)) - used when the intervention is at or above the five level of the trump suit

For example, if the trump suit is hearts and opponents intervene over 4NT with 5D:

Double 0 or 3 Key Cards
Pass 1 or 4 Key Cards
5H 2 Key Cards


Grand Slam Force

The Grand Slam Force is a free bid of five No Trump after a trump suit has been agreed upon.
It asks partner to bid seven of the agreed suit with two of the top three honours, else bid six.
The earlier scheme of responses have been enhanced

6 C Ace or King of trumps
6 D Queen of trumps or 2 trumps more than promised
6 H (space permitting) no honor, but one extra trump
6 N two top honours; allows partner to pick a slam
7 trump two top honours

If the agreed suit is a minor, a scheme similar to Kickback may be employed.


Go to:   Blackwood   Gerber   Roman Key Card Blackwood   Intervention   Grand Slam Force


    Home     Conventions