[AlexJonson]

gordontd, on 2011-April-09, 11:36, said:

I would have thought seven is the most likely number of spades for this auction, if 3♥ had been natural.

Did partner show a key card, otherwise how would you explain his 4S with QJxxxxx.

If he showed more like KQJxxxx or QJTxxxx and club ace, then very different outcome, if I was opposite, (slam in spades in case there is any doubt).

[blackshoe]

If North has seven spades, then they have an eight card fit. But the likelihood of that, given that North thinks 3♥ was a splinter in support of spades, is pretty slim. Yes, that given is UI to South, so he may be constrained to act as if he believes North has seven spades — which would suggest passing. But it doesn't change the fact that South knows darned well that if he passes, odds are North will be playing in a 4-1 or 5-1 fit.

[Adobe BC]

blackshoe, on 2011-April-07, 11:32, said:

1. What jurisdiction?
2. Why did South not attempt to change 3♥ to 2♥, if the latter was the intended bid?
3. What were the meanings of 4NT and 5♦?

1. The Jurisdiction is ACBL.
2. All that is known is that he didn't attempt to change it.
3. 4N is Key Card Blackwood. 5♦ indicates zero key cards.

[blackshoe]

Since the player did not attempt to change his call, 25A does not kick in.

North's alert and explanation provide UI to South that North believes that South has a spade fit and heart shortage. South has bid BW and then passed a 5♦ response. So there are a couple of questions to answer: is pass of 4♠ an LA to 4NT? Is bidding something over 5♦ an LA to passing? If the answer is yes in either case, then could the action taken demonstrably be suggested by the UI? If the answer to that is yes, then if the action not taken gives a better result for the NOS, the TD should adjust the score. But the TD needs to investigate thoroughly, determine all the facts, and in particular take a poll or two to determine what the LAs are.

Having done all that, let's say that the TD determines that pass of 4♠ was an LA to 4NT, that 4NT could demonstrably have been suggested by the UI, and that NS do worse in 4♠ than in 5♦. The TD should adjust the score for EW to whatever number of tricks in 4♠ is likely, and for NS to whatever number of tricks is at all probable. Without looking at the hands, let's say that 4♠ is likely to go down two, but might possibly go down three. Let's also say that EW are unlikely to double 4♠ (perhaps for fear of giving NS an "out"). Then the TD adjusts to 4♠ down 2 for EW, and to 4♠ down 3 for NS. Law 12C1e (the ACBL version) applies. The irregularity to which that law refers would in this case be the 4NT bid.