[lamford]

 pran, on 2015-May-15, 10:52, said:

How does North "know" for a fact that the ♣10 led by South was a singleton?

He does not. If partner has a doubleton club, which is the only alternative as you can see the nine and they were playing standard leads I believe, then cashing a red ace is even worse. A high club does not cost if partner has a doubleton.

I tend to think SB deserves three PPs on the same hand. He concluded from the fact that his partner dropped two cards that his partner had been in a hurry to lead a singleton. He used the UI of what these cards were on two occasions, and he did not carefully avoid taking advantage of the UI. In addition his play of the three of clubs used the UI that he "knew" his partner had a singleton. Otherwise he would have returned a medium club.

It is quite possible, in fact more likely, that East has ♠KQxxx ♥xxx ♦xx ♣Kxx or ♠KQxxx ♥xx ♦xxx ♣Kxx or even ♠KQxx ♥xxx ♦xxx ♣Kxx. In all cases, cashing a red ace is wrong and in the last case you need to cash both red aces to let it through (in some cases declarer can make anyway by playing a diamond to the nine, but has no reason to do so). North only cashed the red aces because he cheated selected from logical alternatives one demonstrably suggested by the three pieces of UI. Tut, tut, SB.

[lamford]

 mycroft, on 2015-May-15, 10:15, said:

I freely admit I had a braino on my last comment - I just didn't see the problem. I must have been asleep (it was 1000, all decent directors are still asleep).

 mycroft, on 2015-May-15, 10:15, said:

Yes, I do think that the fact that partner has a stiff club is AI

How do you conclude this? From partner's seeming haste to lead it? I would suggest that you need to sleep until 1230.

[lamford]

 pran, on 2015-May-15, 10:52, said:

I agree that North is allowed to plan his play based on that assumption (which can hardly be derived from the penalty cards) and the hope that South has a trump high enough to execute an uppercut. That obviously leads to a permissible line of play cashing the two red Aces and play of a second club.

When people use "obviously" they are often on uncertain ground. It is "obvious" to me that playing a club at trick two is a logical alternative, as cashing either red ace may let through the contract immediately. South is around 68:28 to have a doubleton club rather than a singleton. No doubt he is a strong favourite to have a singleton when he leads it so quickly that he drops two other cards at the same time.

[RMB1]

 lamford, on 2015-May-16, 04:22, said:

... No doubt he is a strong favourite to have a singleton when he leads it so quickly that he drops two other cards at the same time.

Especially if the cards he drops are not clubs.

[pran]

 lamford, on 2015-May-16, 04:22, said:

When people use "obviously" they are often on uncertain ground. It is "obvious" to me that playing a club at trick two is a logical alternative, as cashing either red ace may let through the contract immediately. South is around 68:28 to have a doubleton club rather than a singleton. No doubt he is a strong favourite to have a singleton when he leads it so quickly that he drops two other cards at the same time.

You may be aware that I explicitly wrote "based on this assumption".

That does not imply that I find this assumption likely and I certainly do not discuss its rationality.

But if we accept that North assumes (or hopes) that South had a singleton Club and has a worthy trump then his line of play seems "obviously" correct (unless we can show that his assumption and/or hope is mainly based on the existence of the penalty cards, which I find rather questionable.)

[lamford]

 pran, on 2015-May-16, 06:37, said:

But if we accept that North assumes (or hopes) that South had a singleton Club and has a worthy trump then his line of play seems "obviously" correct (unless we can show that his assumption and/or hope is mainly based on the existence of the penalty cards, which I find rather questionable.)

North's assumption or hope that his partner has a singleton club and his assumption or hope that partner's penalty cards are in hearts and diamonds are all based on UI. The AI, that partner led a club without dropping any other cards and without undue haste, makes returning a club at trick two a logical alternative. It is "obviously" the best defence as well, and cashing the two red aces before playing a club is "obviously" cheating selecting from logical alternatives one demonstrably suggested by the UI.

Even if North hopes or assumes that South has a singleton club, he must put this hope or assumption out of his mind, because it is at least partially derived from UI.

[pran]

 lamford, on 2015-May-16, 07:17, said:

[...]
Even if North hopes or assumes that South has a singleton club, he must put this hope or assumption out of his mind, because it is at least partially derived from UI.

Would you care to elaborate on the nature of that UI?

[lamford]

 pran, on 2015-May-16, 07:44, said:

Would you care to elaborate on the nature of that UI?

a) That South led quickly, and dropped two cards in his haste, as stated in the OP. That makes it much more likely that he has led a singleton, but that is UI. As RMB1 points out, the fact that the penalty cards were not clubs strongly suggests that the lead was a singleton. North is not allowed to know what the penalty cards are or how they came to be penalty cards. The most likely card to be dropped is one of the same suit as the one led, providing UI that South is more likely to have a singleton than the a priori probability of about 68:28.

b) The fact that South's penalty cards are the ten of hearts and the ten of diamonds makes it more attractive to cash the aces in those suits. If either penalty card were a small trump, then North would play a club, as cashing either ace could be fatal. North is using the UI of the identity of the penalty cards in both cases. The logical alternative of a club has become less attractive by viewing the penalty cards, as no trump promotion is possible without cashing both red aces first.

[blackshoe]

 lamford, on 2015-May-16, 08:21, said:

a) That South led quickly, and dropped two cards in his haste, as stated in the OP. That makes it much more likely that he has led a singleton, but that is UI. As RMB1 points out, the fact that the penalty cards were not clubs strongly suggests that the lead was a singleton. North is not allowed to know what the penalty cards are or how they came to be penalty cards. The most likely card to be dropped is one of the same suit as the one led, providing UI that South is more likely to have a singleton than the a priori probability of 68:28.

b) The fact that South's penalty cards are the ten of hearts and the ten of diamonds makes it more attractive to cash the aces in those suits. If either penalty card were a small trump, then North would play a club, as cashing either ace could be fatal. North is using the UI of the identity of the penalty cards in both cases. The logical alternative of a club has become less attractive by viewing the penalty cards, as no trump promotion is possible without cashing both red aces first.

In your op, you asked "how do you rule?" If you knew the answer all along, why did you ask the question?

[RMB1]

 blackshoe, on 2015-May-16, 08:30, said:

If you knew the answer all along, why did you ask the question?

lamford wouldn't be the first to post a ruling question (even a composed one) when they think they knew the answer; and he won't be the last

[blackshoe]

 RMB1, on 2015-May-16, 08:40, said:

lamford wouldn't be the first to post a ruling question (even a composed one) when they think they knew the answer; and he won't be the last

Noted. I'd still like to know his motivation.

[lamford]

 blackshoe, on 2015-May-16, 08:50, said:

Noted. I'd still like to know his motivation.

Because I expected there to be a massive difference in the application of Law 50E by TDs worldwide, partly because they have been misled by gibberish from the WBFLC, which contradicts an earlier minute from the same body. [Actually, I lie; my motivation was to see how many upvotes the thread would get - a purely selfish motivation].

In addition, I asked "How would you rule?" I did not know the answer to that question, so my motivation was just that, to find out how the TDs on this forum would rule.

[pran]

 pran, on 2015-May-16, 07:44, said:

Would you care to elaborate on the nature of that UI?

 lamford, on 2015-May-16, 08:21, said:

a) That South led quickly, and dropped two cards in his haste, as stated in the OP. That makes it much more likely that he has led a singleton, but that is UI. As RMB1 points out, the fact that the penalty cards were not clubs strongly suggests that the lead was a singleton. North is not allowed to know what the penalty cards are or how they came to be penalty cards. The most likely card to be dropped is one of the same suit as the one led, providing UI that South is more likely to have a singleton than the a priori probability of 68:28.

b) The fact that South's penalty cards are the ten of hearts and the ten of diamonds makes it more attractive to cash the aces in those suits. If either penalty card were a small trump, then North would play a club, as cashing either ace could be fatal. North is using the UI of the identity of the penalty cards in both cases. The logical alternative of a club has become less attractive by viewing the penalty cards, as no trump promotion is possible without cashing both red aces first.

I agree with your point b) but am rather reluctant to agree with the logic in point a).

Frankly I am a bit puzzled by the deductions from dropping the two red tens together with the opening lead. How did that happen? Did he sort his cards according to rank rather than denomination? If that had been my hand the two tens would have been far away from each other (although the ♦10 might quite likely have been next to the ♣10).

[dburn]

North does have some AI - East has not required a spade shift, as he would have done had either of South's penalty cards been a trump.

[lamford]

 pran, on 2015-May-16, 09:11, said:

Frankly I am a bit puzzled by the deductions from dropping the two red tens together with the opening lead. How did that happen? Did he sort his cards according to rank rather than denomination? If that had been my hand the two tens would have been far away from each other (although the ♦10 might quite likely have been next to the ♣10).

There are two possibilities, given that it was the Rueful Rabbit. The less likely one is that he had recently been playing Canasta and sorted his hand with cards of the same rank together. The other more likely one is that he sorted black, red, black, red, as he usually does, as that minimises the number of times he revokes. He had also been advised not to always sort in the same order within suits, as unscrupulous players can work out when a card is withdrawn from his hand how many higher cards he has. He actually sorted his hand ♠ J9 ♥ 2346T ♣ T ♦ T8532. North could conclude from his knowledge of RR's sorting habits that the "lead" of the three tens is almost certain to include a singleton club.

Are you saying that neither the haste of the opening lead, nor the fact that the penalty cards are not clubs is UI?

[lamford]

 dburn, on 2015-May-16, 09:35, said:

North does have some AI - East has not required a spade shift, as he would have done had either of South's penalty cards been a trump.

Not if he had ♠KQxx ♥xxx ♦xxx ♣Kxx, ♠KQxx ♥xx ♦xxx ♣Kxx or ♠KQxx ♥xx ♦xxx ♣Kxx when he would hope that North would try for a trump promotion by cashing one or both red aces first on a fishing expedition for non-existent red penalty cards. East would know that North is not allowed to know that the penalty card is a trump either. The only time East might require a spade lead is when he has four clubs and the penalty card is the queen of spades, the only dangerous layout.

[pran]

 dburn, on 2015-May-16, 09:35, said:

North does have some AI - East has not required a spade shift, as he would have done had either of South's penalty cards been a trump.

Requesting a spade shift (from North) was not an option for East?

[pran]

 lamford, on 2015-May-16, 09:40, said:

There are two possibilities, given that it was the Rueful Rabbit. The less likely one is that he had recently been playing Canasta and sorted his hand with cards of the same rank together. The other more likely one is that he sorted black, red, black, red, as he usually does, as that minimises the number of times he revokes. He had also been advised not to always sort in the same order within suits, as unscrupulous players can work out when a card is withdrawn from his hand how many higher cards he has. He actually sorted ♠ J9 ♥ 2346T ♣ T ♦ T8532. North could conclude from his knowledge of RR's sorting habits that the "lead" of the three tens is almost certain to include a singleton club.

Are you saying that neither the haste of the opening lead, nor the fact that the penalty cards are not clubs is UI?

Would you say that if South had not exposed the two "extra" cards with his opening lead (so that there had not been any penalty cards at all) then the "haste" of the opening lead was such as to prohibit North from continuing that suit?

[lamford]

 pran, on 2015-May-16, 09:52, said:

Would you say that if South had not exposed the two "extra" cards with his opening lead (so that there had not been any penalty cards at all) then the "haste" of the opening lead was such as to prohibit North from continuing that suit?

No, because then there is no other LA to a club. If South has a doubleton, nothing is lost as one pitch on the king of clubs is of no value. If South has a singleton club and the queen of spades, then a club gains. Cashing a red ace can never gain. I find it quite remarkable that seemingly intelligent people on here can find no ethical fault with North's line of cashing both red aces. For me the only issue is the size of the PP.

[lamford]

 pran, on 2015-May-16, 09:47, said:

Requesting a spade shift (from North) was not an option for East?

dburn is suggesting that North has AI that the penalty card is not a small spade because of the lack of prohibition of a spade lead. I do not think North can conclude this for the reasons I gave above.