Tuesday, July 3, 2007

An interesting problem hand posted on BBF leads to an interesting auction:

Opener: ♠QJ10xxx ♥Axxx DQx ♣A

Responder: ♠A9xxxx ♥K DKx ♣KQxx

The auction seems rather straight-forward for the start:

1♠ (easy opening)
2♣ (I hate 2NT with 6-4 pattern)
2♥ (natural)
2♠ (sets trumps -- start cuebidding)
2NT (not two of the top three spades)
3♣ (two of the top three clubs, and Opener's weakness in trumps is not fatal)
3♠ (no diamond control, not two top hearts, but one top spade honor; note that this promises two or more diamonds, limiting pattern to 5422/5431/5440/6421/6430/7420/6520/5530/5521)
3NT (serious interest)
4♣ (one of the top three clubs; pattern is now 5422/5431/6421/5521)
4D (diamond control)
4♥ (heart control -- Ace or King)

Note that 4♥ is not Last Train because only the Serious 3NT bidder can use Last Train.

Responder now knows that Opener has the club Ace, the heart Ace, and one of the top spades. He also knows that Opener does not have the diamond Ace or a diamond stiff. Opener, therefore, has: (K/Q)xxxx(x)-Axxx(x)-(Q/x)x(x)-A(x)

So, Responder wants to know (a.) if Opener has the spade King or a sixth spade and (b.) if diamonds are protected.The five-level should be relatively safe, although admittedly we might lose a spade and two diamonds with a diamond lead.

One route is to bid 4NT as 1430 RKCB and hope for the King and for no diamond problem. If Opener had held the spade King, Opener would bid 5♣, which allows a neat 5D call to ask about the diamond Queen. As Opener has already denied the King, 5D cannot ask about the diamond King. Further, as Opener must have ♥A/♣A/♠K for this three controls, and as he has denied two top spades, the trump queen has already been denied by virtue of prior cuebids and the 1430 answer). Thus, 5D cannot be asking about the trump Queen.

A better course, however, may be a simple quantitative 5♠ call. As Opener cannot have another club card, spade card, or heart card of any interest, and cannot have the Ace or King of diamonds, or diamond shortness for that matter, the only interesting unknown card is the diamond Queen. As 4NT would clarify the spade situation as far as honors and would allow Opener to show the diamond Queen (see above), the inference is that Responder has play for slam opposite less than this. It is a tight inference, but there nonetheless. In the end, the sixth spade and probable useful diamond Queen should be enough to accept, whether on general principles or because Opener actually figures out the (esoteric?) nuance.

Of course, one might say that Opener needs Kxxxxx and the diamond Queen to accept. But, if Responder needs that hand, he would sign off at 4♠. Remember that a cuebid (4D) that yields the only possible cuebid (4♥) cannot result in a "sign off." 4♠ after 4♥ would still be ever-so-slightly forward going.

That last point should perhaps be restated. If the style is conservative, Opener being concerned about diamond-diamond-trump as three losers and not entering the five-level, Opener should probably bid on after a 4♠ call from Responder. A 5D cue, showing the diamond Queen, might work well. Then, Responder could last train if he needed Kxxxxx or simply bid the slam otherwise. Opener would surely not cue 5D with Qxxxx-Axxx(x)-Qx(x)-A(x).

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