The Sydney Morning Herald – Nov 22, 1981 by Dick Cummings
Once upon a time it was a safe bet to assume that a bid of four no-trumps from your partner in almost any position was an ace ask Blackwood convention. At least there were no misunderstandings. It came to be realised, nevertheless, that the use of 4NT just as Blackwood was highly inefficient. A sensible principle soon emerged: 4NT is natural when there has been no suit agreement and it is direct «raise» of no-trumps.
In sequences such as, opener: 1NT or 2NT; responder: 4NT accepeted practice is «I am interested in a slam in no-trumps; what do you think?»
Other exceptions developed on logical lines. In cue-bidding sequences, 4NT can be used as a pivot (neither Blackwood or natural); and in competitive auctions it is often played as a takeout device. Nowadays the affair has reached a further dimension.
Players are falling over themselves to get off the Blackwood band-waggon and use 4NT as a «general slam try somewhere.» There are signs of jealousy among rival groups in Sydney. As a sort of «who plays Blackwood the least?» competition.
My position is somewhere in the middle. Speaking frankly, would prefer to be playing 4NT as non-Blackwood more often than I currently do in partnership with Tim Seres. However, the evidence is that to drop the convention altogether is to court trouble. For an example of 4NT as an inferential slam invitation in no-trumps, offer board Number 1 of the Bermuda Bowl final in Port Chester:
Dealer North neither Vulnerable
Opening lead by East 10 of hearts.
Munir and Fazli use the Acol system. Theirs was a sensitive sequence, showing modern, natural bidding at its best. Although South held a heart suit, his two hearts was «fourth suit forcing», the correct move on a hand too strong for 2NT (11 to 12 points) or for 3NT (13 to 14 points). North’s three clubs confirmed a good suit and denied a reliable stopper in hearts. Then, when he heard the continuation of 3NT, Munir had a good picture of Fazli’s strength. The message of his next bid, 4NT, was, «I’m quite keen on my hand; how about a slam in no-trumps?» His partner, holding a key card in the king of clubs, was happy to accept. He bid six clubs rather than 6NT because of his doubleton spade, which could conceivably yield an extra trick via a ruff. Munir left it at that and was untroubled to chalk up 12 tricks 920 to Pakistan.
At the other table, Arnold and Soloder for the US had an identical sequence to the point of 4NT; but they finished in a contract of 5NT. The queen and jack of hearts won the first two tricks. Arnold could see he had missed a slam if clubs were breaking; so he played for them not to break! At trick three he ran the eight of clubs, losing to West’s jack. That was 460 to the US but 10 imps to Pakistan.