Bidding Quiz BRIDGE

Some sequences of bidding are regarded as impossible — that is, you simply can’t have a hand that fits the bids you’ve made. In each of the following sequences, specify whether South’s last bid is Possible or Impossible.

1. Impossible. Two notrump indicated 20 or 21 points, balanced distribution and allaround strength. Having spoken his piece by opening two notrump and responding to North’s Stayman inquiry, South cannot logically carry on to six spades when his partner might have as little as five or six high-card points for his bids. If there is a slam, the impetus must come from North, who knows much more about the combined strength of the two hands.

2. Possible. In general, when responder names a new suit, opener cannot pass. But there is an exception to this rule if opener specifically rebids one notrump, limiting his high-card strength and distribution. The two-heart bid here can therefore be passed. With a game-going hand, North could jump to three hearts to force South to bid again.

3. Possible. Four notrump is not Blackwood in this sequence. North should have 16 or 17 points and is inviting South to bid a slam in notrump if he has a maximum for his opening notrump bid. If South has 15 points, he should pass.

4. Impossible. Two diamonds was a jump-shift indicating 17 or more points and interest in slam. Therefore, the partnership is committed to reaching at least a game contract. North is most likely still angling for a slam and is seeking more information.

5. Impossible. Two notrump promised 13 to 15 points and committed the partnership to game. South cannot make a bid that is forcing to game and then change his mind at his next turn. North is presumably unhappy with notrump, but that doesn’t mean South can pass. Some partnerships now play that the jump to two notrump over a minor-suit opening shows 11 or 12 points, in which case North’s three club bid could be passed.

Tomorrow: Solution to a predicament.