[suprgrover]

East-West are both competent players but were not able to stay on the same wavelength on this auction. Their agreement (like many club players in the ACBL) is that Texas transfers are used to sign off at the 4-level over a natural NT bid, and that strong hands do not bid this way.

What are East's logical alternatives at his second turn to call. And what are West's logical alternatives after each of those (yes, if East passes this second question is moot)?

---

2D=natural and weak; 2NT=15-18, natural; 4H=intended as natural, but East believes the agreement is that it is a transfer to spades.

[billw55]

If their agreement is that 4♥ is a transfer, then 4♠ is east's only LA.

After that, west continues to bid naturally. 5♣ seems clear but maybe someone could convince me that 5♥ is allowable.

[nate_m]

Unless West visibly reacts or something, East doesn't have UI and so ought not to be constrained.

West has UI in that pard probably alerted/announced. I think this is entirely duplicated by the AI that partner has bid anything other than pass. This is not the same as say, an auction like 1NT-(2♣)-2♦-P-2♥ where the 2♦ bid was intended as natural. The 2♥ bid does not necessarily show the wheels have come off, so the 2♦ bidder may not choose a LA suggested by the fact that 1NT opener thinks it's a transfer auction. In the actual auction there exists no hand that would EVER bid 4♠ after 4♥ UNLESS it was interpreted as Texas. IMO West should not be constrained either because AI duplicates UI.

[aguahombre]

As said, East has no UI at the time he bids 4S. Absent any squirming by West, he won't have any UI thereafter, either.

It has been established here in very old threads that an alleged Texas followed by 5H, unless it has some systemic meaning for this pair, is an obvious correction.

West has enough AI from the 4S bid itself, since 4H was not forcing or slammish. Bidding 5C would be suicidal. West already knows East misunderstood the auction, and is not required to propel it into the stratisphere.

Off-topic: a good idea for partnerships to reaffirm their methods. This thread, since the situation doesn't come up very often, was an opportunity for us to do so.

After a 2NT overcall of a weak 2-bid, we switch from systems on to approach-forcing 3-level bids and natural 4M jumps.

[blackshoe]

nate_m, on 2013-November-19, 19:59, said:

IMO West should not be constrained either because AI duplicates UI.

"AI duplicates UI" does not relieve a player who has received UI from his obligation not to use it.

[aguahombre]

blackshoe, on 2013-November-19, 22:54, said:

"AI duplicates UI" does not relieve a player who has received UI from his obligation not to use it.

I don't believe that is a concern here. Nor is it a concern in most cases. Authorized information is usable. Unauthorization is not. When a player has both, and they lead to the same conclusion, he is using the AI and not the UI. If he can articulate the AI he is using, good luck proving he is not telling the truth.

[GreenMan]

blackshoe, on 2013-November-19, 22:54, said:

"AI duplicates UI" does not relieve a player who has received UI from his obligation not to use it.

LHO deals, my partner opens 1♠ out of turn. RHO does not accept. LHO passes, partner opens 1♠. Is the fact that he has 12-21 HCP and 5+ spades AI or UI?

[campboy]

If the UI is duplicated by the AI then the UI gives you no extra information. So in fact, while it may be U, it isn't really I.

[barmar]

The issue isn't whether the AI duplicates the UI, the issue is whether the AI provides enough I to limit your LAs. If you only have one LA because of the AI, then you can't be prohibited from choosing it because it also happens to be suggested by the UI. That's the case in this particular thread.

But there can be other situations where the AI results in two or more LAs, and the UI suggests that one of them will be more successful. In that case, you may not select that option, even if it's the one you would have been more likely to choose simply on the AI alone.

[WellSpyder]

barmar, on 2013-November-20, 05:07, said:

But there can be other situations where the AI results in two or more LAs, and the UI suggests that one of them will be more successful. In that case, you may not select that option, even if it's the one you would have been more likely to choose simply on the AI alone.

But if the UI really does provide the same information as the AI, it can't suggest one of the LAs is more likely to be successful than you could judge based on the AI alone.

[barmar]

WellSpyder, on 2013-November-20, 05:12, said:

But if the UI really does provide the same information as the AI, it can't suggest one of the LAs is more likely to be successful than you could judge based on the AI alone.

Sure it can, because something can be an LA even if it's not the one you judge more likely to be successful. It's an LA as long as a significant number of your peers would consider it, and some might choose it.

The odds of success are not a significant factor when deciding LAs, but they are a factor when deciding whether you can select it when constrained by UI.

[campboy]

barmar, on 2013-November-20, 05:25, said:

Sure it can, because something can be an LA even if it's not the one you judge more likely to be successful.

The issue is not whether it's an LA, the issue is whether it's suggested. And if the UI adds no new information then it can't suggest anything.

[suprgrover]

aguahombre, on 2013-November-19, 21:29, said:

As said, East has no UI at the time he bids 4S. Absent any squirming by West, he won't have any UI thereafter, either.

It has been established here in very old threads that an alleged Texas followed by 5H, unless it has some systemic meaning for this pair, is an obvious correction.

Let's say that (1) West squirms over the 4♠ call and bids 5♥, and (2) 5♥ has no systemic meaning for this pair because they don't use Texas transfers to do anything other than sign off. Obviously, East has UI from West's squirming, but is their now any logical alternative to passing 5♥?

[blackshoe]

aguahombre, on 2013-November-19, 23:09, said:

I don't believe that is a concern here. Nor is it a concern in most cases. Authorized information is usable. Unauthorization is not. When a player has both, and they lead to the same conclusion, he is using the AI and not the UI. If he can articulate the AI he is using, good luck proving he is not telling the truth.

This is a flawed interpretation of the law. In particular, Law 16B1{a} does not mention AI at all — it says that when a player has UI, he may not choose from among logical alternatives one that could demonstrably have been suggested by the UI. The presence of AI "saying the same thing" is irrelevant.

[helene_t]

no but the presence of ai means he doesn't have ui. The information he has is that 4♥ was interpreted as texas. That information is either ai or ui.

It would be different if the alert reinforced his suspicion. But here he knew for 100% that 4♥ was taken as a transfer, just from the 4♠ bid alone.

[GreenMan]

In my example, obviously if LHO opens e.g. 1♦ instead of passing and partner overcalls 1♠, everyone would agree that I have AI that he has spades and values, and UI that he is not in the 8-11 range (or whatever distinguishes opening and overcalling hands in our partnership). The overcall and opening bid convey different, overlapping, sets of information, and the parts outside the intersection of those sets are UI.

But I would think, and it seems others agree, that if the two calls convey the SAME set of information that the whole set is AI. But Ed, at least, seems to be arguing that some part of that set is UI, and I'm supposed to sort out exactly what it is, and thus what actions it suggests. So how does a player do that?

[blackshoe]

GreenMan, on 2013-November-19, 23:31, said:

LHO deals, my partner opens 1♠ out of turn. RHO does not accept. LHO passes, partner opens 1♠. Is the fact that he has 12-21 HCP and 5+ spades AI or UI?

I suppose it depends on whether the original BOOT is "another source" (Law 16A1{a}). I would say no: the source is partner in either case (the original BOOT or the replacement bid). So the information from the replacement call is AI. Once might say the only "I" from the original BOOT is that partner was a bit too eager to open — this may imply that he has more than a minimum for his opening bid. That would be UI.

[blackshoe]

campboy, on 2013-November-20, 04:31, said:

If the UI is duplicated by the AI then the UI gives you no extra information. So in fact, while it may be U, it isn't really I.

That's not necessarily true. See my previous post.

[blackshoe]

barmar, on 2013-November-20, 05:07, said:

The issue isn't whether the AI duplicates the UI, the issue is whether the AI provides enough I to limit your LAs. If you only have one LA because of the AI, then you can't be prohibited from choosing it because it also happens to be suggested by the UI. That's the case in this particular thread.

But there can be other situations where the AI results in two or more LAs, and the UI suggests that one of them will be more successful. In that case, you may not select that option, even if it's the one you would have been more likely to choose simply on the AI alone.

I agree with this message.

[blackshoe]

helene_t, on 2013-November-20, 07:29, said:

no but the presence of ai means he doesn't have ui.

Not generally true.

helene_t, on 2013-November-20, 07:29, said:

The information he has is that 4♥ was interpreted as texas. That information is either ai or ui, it can't be both. In this case it is ai.

How does he know that 4♥ was interpreted as Texas?