UI or not UI

[Trinidad]

I do not buy this at all. The laws talk about one alternative being suggested over another. So what we have to consider is purely whether spades is suggested over hearts; the fact that clubs is suggested over both is irrelevant.

The fact that a spade lead has a slightly higher chance for success than a heart lead is a red herring. If you can make your contract:

a ) on a finesse

b ) on dropping a singleton king, missing 8 cards in the suit

c ) on dropping a singleton king, missing 9 cards in the suit

 

you are not going to analyze that dropping the king missing 8 would be a better play than dropping a king missing 9. You take the finesse. Any other play would be silly.

 

This is the same thing. If partner doubles, you lead a club. It is irrelevant that a spade lead would have a 0.000001% probability of finding partner's suit and a heart lead would have a 0.0000001% (1 extra zero) probability of finding partner's suit, because we are not talking about success probabilities, we are talking about the probability that a player would chose this action: what percentage of players would chose this action.

 

The probability for dropping a king missing 8 cards in the suit is an order of magnitude higher than the probability for dropping a king missing 9 cards in a suit, but it doesn't matter: 0.0000000000% of the players would ever chose that play.

 

In a similar way, the probability for hitting partner's spade suit may be 10 times higher than the probability that you will hit partner's heart suit. It doesn't matter, since both probabilities are a 100 times smaller than that for finding partner with clubs, which means that 100.000000% of the players would lead a club. If 0.0000000% of the players would lead a heart with the UI and 0.0000000% would lead a spade with the UI, how can the UI suggest a spade lead over a heart lead, even if the probability for success for a spade lead is an order (or 4 orders for all I care) of magnitude higher than that for the heart lead?

 

Rik

[Trinidad]

The possession of the nine is strong reason to think that a top heart would normally be led. Indeed, I recall a Woolsey article where he argued leading a top card from KQ8x(x) was theoretically best.

I recall an article where someone (don't remember who) argued that it made a big difference whether you expect the strength to be over or under you. With strength over you start with the top card, with strength under you start low.

 

Of course, it doesn't matter what articles we have read. It matters what North read.

 

Rik

[lamford]

Of course, it doesn't matter what articles we have read. It matters what North read.

No that does not matter either. All that matters is what peers of North, playing the same methods, would lead without the UI, and what the UI demonstrably suggests. And any arguments in favour of a spade lead, even if they had validity which I do not accept, are irrelevant, as all that is needed for an adjustment (assuming we decide that the UI demonstrably suggests a non-heart lead) is for something like 20% of North's peers to seriously consider a heart lead, and 10% to actually choose it. That seems incontrovertible, on any poll.

[Finch]

If South was thinking about doubling, the double normally asks North to find South's suit. That means that the suggested lead would be a club.Suppose that South would have doubled to ask North to find his suit. Is there anybody here who would have tried a spade with the North hand? Or would everybody have led a club?I think that everybody (100%) would have led a club, because the club lead has objectively the best chance to find partner's long suit. There are no guarantees, but it is crystal clear that it is the percentage play. Any other lead than a club would be really, really dumb. If we would be talking about LA's here: there are no LA's, not even remotely.So, the BIT suggests a club lead and a club lead only. The BIT cannot suggest a lead that nobody would make if South actually would have doubled, rather than just thought about it. Hence, a spade lead is not suggested by the BIT, simply because the BIT says that it would be a really, really dumb lead.Rik

 

 

The only thing I am sure is that 9 tricks are not being taken, low heart is a normal lead with that holding and there is no reason to think other card would be used.

 

 

There are a lot of 'normally's going on here.

I am aware of 4 common meanings for the auction 1NT P 3NT dbl

1. Lead a spade
   
2. Find my major
   
3. Find my suit
   
4. It's going off / undiscussed
   

 

The one I have seen by far the most often is 'find my major'

If this pair played double as 'lead a heart' (which I haven't seen, but I can see an argument for it) then no-one would be ruling against them when he leads a spade.

 

Similarly, I think the K or Q (depending on honour leading agreements) is the 'normal' lead form KQ9x but I know that others don't.

 

What matters is what this pair's agreements are, not what 'normal' agreements are.

 

p.s. there is an argument that when a sophisticated player thinks then passes he wants a lead that isn't the one that double suggests (he is working out that he can't double, because it won't get the right lead). But every time I have seen this or similar pauses at the table, it's never been because of that - it's always been because they are simply deciding whether to double or not and they have the holding that double would suggest.

[billw55]

There are a lot of 'normally's going on here.

I am aware of 4 common meanings for the auction 1NT P 3NT dbl

1. Lead a spade
2. Find my major
3. Find my suit
4. It's going off / undiscussed

And for 1, 2, or 3, a heart lead is obviously ruled out.

 

I still think this is an adjustment unless someone can argue that leading a heart is not a LA.

[Sjoerds]

I still think this is an adjustment unless someone can argue that leading a heart is not a LA.

 

I polled what to start after this sequence without of course the UI

 

2x ♠x

1x ♦x

1x ♥K

 

I must say I was a bit surprised, but most argued that starting a ♥ would bring you only 1 trick and if you wait you get two.

 

I didn't change the score

[helene_t]

I really don't like EW's accusation. It is quite possible that North wouldn't have found the spade lead without the BIT but we can't know. If anyone deserves a PP it is EW.

[Trinidad]

There are a lot of 'normally's going on here.

I am aware of 4 common meanings for the auction 1NT P 3NT dbl

1. Lead a spade
   
2. Find my major
   
3. Find my suit
   
4. It's going off / undiscussed
   

 

The one I have seen by far the most often is 'find my major'

That's very nice. But I suspect that where Sjoerd is playing 4 is the most common one, followed at a long distance by 3. If Sjoerd would suggest meanings 1 and 2 at his club, the members would start to gaze at him and wonder whether he has been smoking those funny mushrooms again.

 

Rik

[billw55]

That's very nice. But I suspect that where Sjoerd is playing 4 is the most common one, followed at a long distance by 3. If Sjoerd would suggest meanings 1 and 2 at his club, the members would start to gaze at him and wonder whether he has been smoking those funny mushrooms again.

 

Rik

OK, this is different situation that I expected. In this case it sounds like nothing special is suggested, and Sjoerd's poll seems to show that a heart lead has few fans. With these facts, I would now say no adjustment.

[aguahombre]

Great player, strange club --polling players at same club. It does change everything for me, as it did for Bill above..to no adjustment. Maybe a visitor was Declarer.

[lamford]

I polled what to start after this sequence without of course the UI

 

2x ♠x

1x ♦x

1x ♥K

 

I must say I was a bit surprised, but most argued that starting a ♥ would bring you only 1 trick and if you wait you get two.

 

I didn't change the score

Even though you only polled four people, that was enough to establish that a top heart was an LA. You should, I think, also poll to find out what they think is demonstrably suggested by the UI. If, as I believe, that is a non-heart lead, you should still have adjusted, or at the very least have extended the poll.

[Cyberyeti]

Maybe south was thinking about bidding a suit at this vul, 4♠ is one off because the A♣ is wrong and a good save if you weren't going to beat 3N, I don't think any suit is particularly suggested although hearts may be slightly non-suggested.

[aguahombre]

That's very nice. But I suspect that where Sjoerd is playing 4 is the most common one, followed at a long distance by 3. If Sjoerd would suggest meanings 1 and 2 at his club, the members would start to gaze at him and wonder whether he has been smoking those funny mushrooms again.

Perhaps, at this club, the correct thing to do would have been give the peers two polls:

 

1N-3N &

 

1N- (P) 3N (X).

 

This would be time-consuming, however. Sjoerd would have to wait about 15 minutes for them to forget the first poll before doing the second one.

[StevenG]

Even though you only polled four people, that was enough to establish that a top heart was an LA. You should, I think, also poll to find out what they think is demonstrably suggested by the UI. If, as I believe, that is a non-heart lead, you should still have adjusted, or at the very least have extended the poll.

But I'm going to lead a spade without the UI. If I want to use the UI, I'm going to switch to a club, because that's the best chance of finding partner's long suit. Since I've got four spades, it seems very unlikely that partner's suit will be spades. (Given the auction and my hand, what is the (Bayesian) probability that partner's suit is spades?)

 

If we assume that double wouldn't have asked for a spade, then not only does it demonstrably suggest a non-heart lead, it also demonstrably suggests a non-spade lead.

 

Of course, if double does ask for a spade, then the meaning of the UI is completely different.

[lamford]

But I'm going to lead a spade without the UI. If I want to use the UI, I'm going to switch to a club, because that's the best chance of finding partner's long suit.

I agree that the BIT suggests a club over a spade, but it also suggests a spade over a heart. If partner has a suit he wants led, it is most likely to be clubs. However, you know partner does not want a heart lead, so all other suits are demonstrably suggested over hearts, and non-heart leads are therefore breaches of 16B.

[helene_t]

Perhaps, at this club, the correct thing to do would have been give the peers two polls:

 

1N-3N &

 

1N- (P) 3N (X).

 

This would be time-consuming, however. Sjoerd would have to wait about 15 minutes for them to forget the first poll before doing the second one.

Sounds like a reasonable approach but still not bullet-proof. The slow pass could be interpreted as a good hand not suitable for a double (whatever a double would mean for that partnership).

[ggwhiz]

It sure seems like if a heart was led (small or top) and beat the contract the police would be summoned anyway for the previously stated reasons that a spade lead is a legitimate choice and by the UI that partner is not close to broke indicating that a heart may well work. Especially the King if pard has length but realized they aren't good enough quality to double or we control the suit in time to switch to whatever the tank was about.

 

A lead of either minor suit would look like taking advantage of the UI imo but the auction, not the UI suggests a major and I see nothing outrageous or indicated with the choice that was made.

[StevenG]

I agree that the BIT suggests a club over a spade, but it also suggests a spade over a heart.

But it changes the probability of my leading a heart from 0% to 0%. If I use the UI, it changes the probability of my leading a spade from 100% (I think) to 0%. How does that constitute suggesting a spade over a heart?

[campboy]

But it changes the probability of my leading a heart from 0% to 0%. If I use the UI, it changes the probability of my leading a spade from 100% (I think) to 0%. How does that constitute suggesting a spade over a heart?

If the chance of leading a heart without UI was really 0% then it wasn't an LA so there is no issue. And that may be so for you. But suppose for the sake of argument that I am on lead; I believe a heart is an LA for me.

 

With UI -- well, if allowed to use that UI everyone would lead a club, of course. Therefore a club lead will be disallowed (if successful). So if I were unethical I might reason "I have the UI that partner wants me to lead his suit. The most likely lead to work is a club, but I can't lead a club because the director will rule it back. So I'd better try a diamond." Thus -- even though no-one would lead a diamond if allowed to use the UI -- it is suggested over a heart or a spade, because once you rule out a club it is the obvious lead. You can presumably see where this argument is going.

 

(In case it isn't clear, I am not in any way suggesting that the player at the table did anything unethical.)

[StevenG]

If we take the poll as gospel ( :rolleyes: ) then we start with the probability of a spade as 50% and a top heart as 25%. After the UI, the probability of a heart is, presumably, 0%. But what if the probability of a spade is, say, 20%? The probability of a spade has still dropped by more than that of a heart. What is our methodology on this?

 

The difficulty is that a heart, while not a LA for me, is a LA according to Law 16B. But the perception of its importance seems to be skewed by whether you consider it a serious LA, or something that rather scrapes into the list. With multiple LAs, if a minor LA (call it X) becomes less attractive after UI, do you automatically adjust for a non-X choice? Or is it only if it's a LA you perceive (rightly or wrongly) as one of the most likely?

[campboy]

If we take the poll as gospel ( :rolleyes: ) then we start with the probability of a spade as 50% and a top heart as 25%. After the UI, the probability of a heart is, presumably, 0%. But what if the probability of a spade is, say, 20%? The probability of a spade has still dropped by more than that of a heart. What is our methodology on this?

The probability of a spade has gone down less, in the sense that it is has been reduced by 60% whereas that of a heart has been reduced by 100%. But all that is irrelevant anyway, as I keep saying. What matters is not the actual probabilities of a heart or a spade lead, but what they would be if you were forced to lead one or the other. And I think the chance of choosing a spade over a heart would go up from maybe 75% to 100%.

[Trinidad]

If the chance of leading a heart without UI was really 0% then it wasn't an LA so there is no issue. And that may be so for you. But suppose for the sake of argument that I am on lead; I believe a heart is an LA for me.

 

With UI -- well, if allowed to use that UI everyone would lead a club, of course. Therefore a club lead will be disallowed (if successful). So if I were unethical I might reason "I have the UI that partner wants me to lead his suit. The most likely lead to work is a club, but I can't lead a club because the director will rule it back. So I'd better try a diamond." Thus -- even though no-one would lead a diamond if allowed to use the UI -- it is suggested over a heart or a spade, because once you rule out a club it is the obvious lead. You can presumably see where this argument is going.

 

(In case it isn't clear, I am not in any way suggesting that the player at the table did anything unethical.)

This argument is going nowhere.. The probability that anyone would like to lead a spade with the UI is equal to the probability that anyone would like to lead a heart with the UI: zero.

 

As a matter of fact, I asked my wife. Without the UI, she picked a spade lead. I asked whether there were any LA's and she said: "not really, but I guess that someone just out of the bridge course might lead 'fourth best from longest and strongest'". Whatever..

 

But then I gave her the UI and asked what lead it suggested and we had the following, very fast exchange:

"A club."

- "What suit next?"

"A diamond."

- "What suit next?"

"A heart."

- "A heart?!? Why a heart and not a spade?"

"Partner has a long, broken suit and one or two entries. It's obviously a minor, so it doesn't really matter, but you wanted to know the difference between the major suits. So suppose -for argument's sake- that it's a major: If it is hearts, you will get the contract down immediately. If it is spades, declarer will hold the stopper(s), since dummy will likely show up with a good minor to justify his raise to 3NT on a combined 23-24 points or so."

- "All nice, but how did you get the idea that partner has a long, broken suit? Shouldn't he have a solid suit?"

"Of course not. He can't have a solid suit. If he would have had a solid suit, he would not have thought about doubling... He would have doubled... "

 

Rik

[campboy]

Ok, we agree at least that the order starts club, diamond. Obviously you disallow a club. Do you disallow a diamond? After all, just like hearts and spades, the probability of leading a diamond if allowed to use the UI is zero.

[blackshoe]

Could a club demonstrably be suggested over some other LA? Yes. Can't lead a club. Could a diamond demonstrably be suggested over some other LA? Yes. Can't lead a diamond. Could a heart demonstrably be suggested over some other LA? Yes. Can't lead a heart. Could a spade demonstrably be suggested over some other LA? Apparently not. So if a non-spade is led, we adjust to whatever would have happened with a spade lead. The fact that's the lead that would have been made without the UI is irrelevant. The fact that a heart is "only a little bit suggested" is irrelevant. Now you should probably look at the spades and ask "which cards are LAs, and which is suggested over which other one(s)?" In this particular case, I don't think that will be fruitful, but in some others perhaps it might.

 

This reminds me of a more general (and hypothetical) thread we had some years ago: A is suggested over B, B is suggested over C, C is suggested over A. Now what? I don't remember that we came to a satisfactory conclusion. The point being that in our actual case here if a spade could demonstrably be suggested over something else, we're stuck. The law does not provide for a construction such that "A is more suggested over B than is B over C" and so on. So I suppose the choices are to throw the board out for this table (score it as "not played") or treat it as "there are no LAs". Neither is palatable, so I hope I'm right that a spade is not suggested over another suit.

 

Added: the probability of a particular LA is IMO a red herring. The only question is whether it demonstrably could be suggested over another LA.

Edited October 31, 2013 by blackshoe
Added a line.

[Trinidad]

I think it would be good to use a concept of "noise".

 

At some point, actions are so improbable, given the UI, as in a spade or a heart lead here that the difference between the two is less than the "noise".

 

One can say that a spade lead has a 10^-7 probability for succes and a heart lead has a zero probability of succes, if one assumes that the BIT is based on a solid suit. Following this assumption, one could argue that a spade lead is suggested over a heart lead.

 

However, we cannot be sure that the assumption is true. There is always some degree of uncertainty. This uncertainty creates "noise". In this case the uncertainty that our assumption is true (reasonable as it is) is much larger than the difference between the effect of a heart or a spade lead. That means that we cannot discern between the spade and heart lead.

 

In this case, I would think that the probability that the BIT is based on a broken suit is much higher than the probability that a spade lead will be succesful if the BIT is based on a solid suit. P(BIT because of broken suit) >> P(Spade lead is succesful | Partner has a solid suit)

 

Therefore, the error introduced by our assumption is much larger than the difference between the heart and spade lead, making this difference not measurable (below the detection limit of our system).

 

Rik