Ingberman Convention

This convention was named for Monroe Ingberman of New York, who was a mathematician and bridge player. He was also known for Fragment or Splinter bids and the 3NT response as a forcing Major raise. The concept of the Ingberman convention deals with bidding situations, in which the partner reverses and the responder is holding minimum values of 6/7 high card points. The point count, from the perspective of the responder is insufficient to guarantee game and the responder must communicate this information to his partner, in the case that the partner, who has reversed, also has minimum values. The opener may have only 15/16 high card points for the reverse, and there must be an escape sequence available to the responder to avoid a final contract, which may be too high for the partnership to make. The following illustrations should clarify this concept.

1	Pass	1	Pass
2	Pass	2NT	Pass
?

The second response of of 2NT is artificial and is a Relay bid, and it is strongly indicating a holding of values insufficient for game or around the minimum response of 6/7 high card points, with no substantial support in Clubs and/or Diamonds. East is communicating to West that if they hold minimum values for the Reverse, then they should accept the Relay of the 2NT second response and bid 3. East can then pass or correct to 3 for the final contract. If West, on the other hand, has more than a minimum requirement for a Reverse bid, then with the expected minimum values held by East, plus the extra values held by West, the partnership, captained by the West, should refuse the relay.

A correction by East to 3 would be the following auction:

1	Pass	1	Pass
2	Pass	2NT	Pass
3	Pass	3

East could have a holding such as the following:

J98 K864 Q875 54 in which case, East is simply taking a preference for the Diamond suit. The number of trump cards between the partnership could possibly be only seven, meaning some sort of Moysian fit, but which would prove to be a better contract than No Trump, or the lesser of two evils.

Ingberman realized that this concept is definitely not perfect as is all conventions, and included the following bidding sequence to indicate a possible auction, whereby a partnership agreement is definitely required in advance to handle such bidding sequences:

1	Pass	1	Pass
2	Pass	3*

* The question is whether the second response of East of 3, after the Reverse bid shown by West, is forcing for one round, semi-forcing, invitational, game-forcing or non-forcing. His conclusion was that the agreement should be a partnership understanding. The general partnership agreement is that such a bidding sequence should be treated as semi-forcing. The two following illustrations should assist in understanding this feature. West could hold the two holdings shown below or something similar:

95 65 AKJ8 AKQ108

In this case, the best option of West is to simply pass 3.

9 K65 AK84 AK1087

In this case, the best option of West is to bid 4.

Ingberman, however, logically and mathematically surmised that if the Reverse bidder held holdings such as the following:

AJ 74 KQ86 AKQ95 then, with a maximum of values, the Reverse bidder, after the partner has communicated minimum values and little suit support by bidding 2NT on the second round, should simply bid 3NT as the final contract since the high card points held by both approximate the values needed for game.