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ACBL: When does UI become AI?

#1 User is offline   Flem72 

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Posted 2012-August-26, 09:24

Sparked by a long discussion on BridgeWinners following an article by Debbie Rosenberg:

P fails to alert. I gather taht at some point in the auction, P may make a call (usually one that was required by his mistake????) that in effect removes the UI constraints. This question may be way too vague for any clarity at all, but can someone spell out the whys and hows of this kind of thing? Examples welcome, since I don't even know enough to generate one....
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#2 User is offline   blackshoe 

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Posted 2012-August-26, 10:04

You look at your hand. You look at the bidding. You have several possible calls you can make (logical alternatives, or LAs). Which one do you choose?

If you have no UI, you can choose any one you like. If you have UI, then you may not choose an LA which demonstrably could have been suggested over another by that UI.

How does AI figure into it? If the AI eliminates all the LAs but one, you can make that call even if it demonstrably could have been suggested by the UI.

Some will tell you the constraint is even looser, that if you have UI that suggests a call, and AI that also suggests that call, you can legally make that call. They're wrong.
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#3 User is offline   gordontd 

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Posted 2012-August-26, 10:23

If you have UI (unauthorised information), you have UI. However, you may also have AI (authorised information) that reduces the number of logical alternatives (LAs) there are to the action that was suggested by the UI. This may reach the point where there are no LAs to that action, and then you could do it, despite it being suggested by the UI.
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#4 User is offline   rwbarton 

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Posted 2012-August-26, 12:02

 blackshoe, on 2012-August-26, 10:04, said:

If you have no UI, you can choose any one you like. If you have UI, then you may not choose an LA which demonstrably could have been suggested over another by that UI.

How does AI figure into it? If the AI eliminates all the LAs but one, you can make that call even if it demonstrably could have been suggested by the UI.


AI figures into it in a more basic way than that. "could demonstrably have been suggested over another by the extraneous information" means an action that, in view of the UI together with our AI, appears more likely to succeed than it would have based on our AI alone.

For example, we need not consider UI obligations when the opponents ask about a call and our partner explains it according to our agreements and our own understanding at the time of the call.

(I know this is not the kind of scenario the OP envisaged in which we gain AI subsequently to the UI, but answers in this thread ought to apply correctly to this case as well.)
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#5 User is offline   TimG 

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Posted 2012-August-28, 11:06

How about this example:

Your partner opens a 12-14 NT and you respond 2D (transfer to hearts) intending to signoff in 2H, but partner does not announce/alert. Your LHO pass, as does partner. RHO doubles!

You have UI that partner may not know you hoped to signoff in hearts. Are there conditions under which you can/cannot now bid 2H?
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#6 User is offline   blackshoe 

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Posted 2012-August-28, 17:19

 TimG, on 2012-August-28, 11:06, said:

How about this example:

Your partner opens a 12-14 NT and you respond 2D (transfer to hearts) intending to signoff in 2H, but partner does not announce/alert. Your LHO pass, as does partner. RHO doubles!

You have UI that partner may not know you hoped to signoff in hearts. Are there conditions under which you can/cannot now bid 2H?

This gets kind of complicated. My first reaction when partner fails to announce my transfer is usually "Oh, damn, he's forgotten we play transfers!" With some partners it's more "Oh, damn, he's asleep again!" :) In both cases I have UI, but while in the former case it suggests I bid on, In the latter I don't think it suggests anything. (but it may be difficult to convince a director of this, and it will likely be impossible to convince my opponent). When partner passes, it just reinforces my thought. In the first case, I'd feel like I was taking advantage of UI if I bid on (in most cases). In the second, I wouldn't. Note that I haven't said a think about LAs here. I'm not talking about Law 16B — that's the director's part of the ship — I'm talking about Law 73C and its "must carefully avoid taking advantage" provision which is the player's part of the ship.

This hand:

would, I think, qualify as "no logical alternative" to bidding 2, even after an unannounced transfer. Anything better (or less bad) for play in diamonds would not, IMO.
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#7 User is offline   rwbarton 

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Posted 2012-August-28, 21:32

What if we can produce written evidence of an agreement that a pass of the transfer shows tolerance and a bad hand for playing in :)
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#8 User is offline   ahydra 

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Posted 2012-August-29, 05:54

Quote

How about this example:

Your partner opens a 12-14 NT and you respond 2D (transfer to hearts) intending to signoff in 2H, but partner does not announce/alert. Your LHO pass, as does partner. RHO doubles!

You have UI that partner may not know you hoped to signoff in hearts. Are there conditions under which you can/cannot now bid 2H?


Surely you are allowed to bid 2H (keep playing according to the system), but your partner must keep playing according to "the system from his point of view" and correct to 3D if he prefers diamonds, at which point things get interesting?

Yes you have UI from a failure to alert, but I don't really think you should have to try to put yourself in partner's shoes and imagine what he's thinking. How exactly is one meant to know what partner is thinking?

ahydra
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#9 User is offline   mycroft 

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Posted 2012-August-29, 11:25

 ahydra, on 2012-August-29, 05:54, said:

Surely you are allowed to bid 2H (keep playing according to the system), but your partner must keep playing according to "the system from his point of view" and correct to 3D if he prefers diamonds, at which point things get interesting?
Other way up, I'm afraid. You have UI, partner (unless you flinched) does not. If the auction reminds *him* that he's forgotten transfers, he's allowed to wake up (calling the TD and correcting his own failure to Alert/Announce, of course).

If partner had cheerily Announced 2 as a transfer, and then slammed the pass card on the table with a smile, would you pull with some random hand like T86 AJ865 T74 32 ? Of course not - in fact, you'd probably bid 3 when the double gets pulled. You're keeping playing according to the system by passing - partner heard you had hearts and decided to play 2. Maybe he'll change his mind now that he knows about the bad break, and play in the weak hand's long suit - maybe he's 3=2=6=2 and won't. Of course we know it doesn't break badly - well, 4-4 isn't a *bad* break, just unfortunate - but that's based on the UI!).

Quote

Yes you have UI from a failure to alert, but I don't really think you should have to try to put yourself in partner's shoes and imagine what he's thinking. How exactly is one meant to know what partner is thinking?
The UI is obvious - partner forgot to announce, and one of the options - in fact the likely option - is "partner forgot we're playing transfers". If you do anything to cater to the fact that partner forgot as opposed to partner decided to pass *anyway*, it will be ruled back. You don't have to work out what partner *is* thinking, just the likely possibilities that any bridge player could see if explained. And in the case of "failure to Alert", the obvious, clearly demonstrable thought is "partner doesn't think it's Alertable." - that you're showing the non-Alertable meaning.
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