We have seen how to bid over two-level and three-level opening bids. Pre-empts can take another form without a jump in the bidding. This comes in the form of the weak No Trump. An opening bid of one No Trump, taking away the entire one-level, shows a balanced ten to 12 HCP’s.
Weak No Trump works the best when the opponents feel that the contract is being stolen from them and they make an ill-advised bid. The partner of the weak No Trump opener knows his hand and his partner’s hand and is in the best position at the table to decide whether the opponents should play doubled if they step into the wrong auction.
The bidding: West, with a balanced ten to 12 HCP’s, opens One No Trump and partner passes because he knows game is out of reach. South is worried that they are missing a contract and bids his six-card Spade suit. East cannot believe his luck and has an easy double for penalty.
The Play: West leads the King of Hearts and then follows it with the Jack. East wins the Ace of Hearts and puts the Queen of Diamonds on the table. The defense will get two Hearts, two Diamonds and three Spades for down two and 300 points. This is a huge result on a hand that East and West had settled for a part score.
In order to best defend against a weak No Trump, one must have a system of bids that show two-suited hands. Once again, shape and not just points becomes important. If one shows two-suits, there is an element of safety because there is a good chance that partner has a fit with one of them.
A system like Cappelletti is very useful because a double shows a hand of 15 points or more and the desire to let the opponents play doubled. Two Clubs shows an unspecified long suit, Two Diamonds shows both Majors and a bid of a major shows that major and an unspecified minor. Two No Trump asks for the minor.
When partner bids Two Clubs showing a single-suited hand, one bids a relay of Two Diamonds allowing partner to pass or correct. If the Right Hand Opponent does anything besides pass, the relay is not needed.
Weak No Trump paid off for East and West because South should have stayed out of the auction with a poorly-textured suit.