Gerber Convention

Developed by John Gerber in order to learn the number of Aces for NoTrump Slams. Blackwood Convention is not efficient for NoTrump Slams, because it is hard to understand if the bidding 5 NT is Game or a question for the number of Kings.  In this convention number of Aces are asked by bidding 4 Clubs after 1 NT or 2 NT opennings.  The responses are as follows:

4 Diamonds :            0-4 Aces

4 Hearts      :               1 Ace

4 Spades     :               2 Aces

4 NT          :               3 Aces

After then, you can ask the number of King by bidding 5 Clubs, the responses are given in the same manner. If the opponent overcalls 4 Clubs, the responses differ as shown below:

Double        :            0-4 Aces

Pas             :               1 Ace

1st Step      :               2 Aces (for instance 4 Spades over 4 Hearts overcall) and so on. (See DOPI)

If the 4 Clubs bid is doubled, then Redouble shows 0-4 Aces, rest is the same. (See ROPI)

• Rolling Gerber : Number of Kings are asked by bidding the next step after the response to 4 Clubs Gerber. Let's say the response to Gerber is 4 Hearts, then you can ask the number of Kings by bidding 4 Spades. This is a more common application than Rolling Blackwood because the players knows that the game will be NoTrump.