[barmar]

In ACBL, you're not required to alert negative inferences. So you don't have to alert when partner makes some call other than a support double. You also don't have to alert a raise because it promises 4-card support. You only have to alert the support double itself. I think the reason for this is that this meaning of double is artificial and relatively unusual. But pass and raise are pretty close to the meaning they have if you're not playing support doubles.

[Vampyr]

Antrax, on 2011-April-10, 23:04, said:

A new question came up - do you ever give an alert for pass? Last night we had the following auction:
1NT-(X)-P
Partner's pass of a penalty double to 1NT requests opener to redouble, at which point he passes for penalties or we look for a fit etc. Is that alertable?

I don't think that many forum members are familiar with the alert regulations in your NBO. This pass, though, is probably alertable everywhere.

Quote

What about the following situation:
1♦-(P)-1♥-(1♠)
Double now would show 3-card support for hearts. Is a pass in this situation alertable? (since partner now knows I don't have 3 hearts)

Without specific knowledge of the local regulations, I would alert.

[barmar]

Is there an echo in here?

[Antrax]

Well, dan_ehh is a forum member and he seems fairly knowledgeable
I'm not sure in Israel you alert support doubles, I think there's a regulation that says you never alert any double or redouble (and never a call above 3NT).

[aguahombre]

The good pairs seem to always alert a pass when a double would show 3-card support. they alert any other bid, too if they would always double with 3-card support.

[dan_ehh]

Antrax, on 2011-April-11, 00:26, said:

Well, dan_ehh is a forum member and he seems fairly knowledgeable
I'm not sure in Israel you alert support doubles, I think there's a regulation that says you never alert any double or redouble (and never a call above 3NT).

Thank you for the compliment. I'd like to consider myself knowledgeable, yes...
As to your questions, the redouble-demanding pass is very much alertable. Whether the 2nd one (denying 3 card support) is alertable is not clear in the regulations (as far as I know). This is mainly because the regulations are not written in details anywhere visible. I personally alert it, and I think it doesn't hurt to alert. The principle of "when in doubt - alert" is strong in the IBF regulations.
You're right about the doubles and redoubles - they are never alertable regardless of their meaning (another silly regulation in my opinion).



I'd like to add something about announcements. As several posters already said, announcements do not violate the UI laws any more than alerts and explanations do.
The difference is basically what barmar said - announcements are used in very common bidding sequences such as a 1 or 2 level opening bid, stayman, transfers, or other very simple situations. These are auctions where it's extremely unlikely that the announcement will give partner any meaningful UI.
Quantumcat, do you really think someone will forget they play stayman? Or weak 2s? And in the unlikely event that someone is such a weak player that they actually do forget that 2♣ is stayman, not clubs, and the announcement wakes them up, they've probably already misbid that it won't help much, plus the director can usually determine that the announcement gave them UI and that they used it (because they'll be holding clubs, not majors, for the 2♣ bid).

Finally, an interesting and very important point about the announcements: they are designed to protect the announcing side just as much as the opponents.
Example: we play better minor. Occasionally, I open a 3 card minor suit, and LHO has a real suit in this denomination. He wants to overcall it, but obviously can't because that would be artificial.
Under the old regulations, better minor was not alertable in Israel, so LHO would make the pseudo-cheating remark "is that really a ♣/♦ suit?" and then you'd say "promises at least 3" and they'd pass. Then their partner would magically lead the opening bid suit against 3NT...
Under the new regulations, the opening bidder's partner quickly says "at least 3 cards" and the opponent has to shut up. The announcement serves to reduce UI because it negates the element of questioning the opening bid.

[mycroft]

Ah, the dreaded "how many cards does that show?" "Fewer than you, obviously" sequence.

I used to see that before the weak NT Announcement here in the wilds of Canada.

• 1NT - Alert - X was the nuts;
  
• 1NT - Alert - "what is it?" - "12-14" - X was "equal values";
  
• 1NT - Alert - "what is it?" - "12-14" - p was "feel free to balance, partner";
  
• 1NT - Alert - pass was "got nothin', pard"

with similar gredations on overcalls. Our score on weak NT auctions in 1991 went up about 20%. I can't imagine why.

And as for QuantumCat (besides the arguments that Alerts do the same thing, even without explanations, and the law around it), L40B2a says in part, "The Regulating Authority may prescribe alerting procedures and/or other methods of disclosure of a partnerships methods" - so if they say ya gotta Announce, ya gotta Announce (and, more importantly, and unfortunately, not always adhered to, if they don't say ya gotta Announce, then ya better not Announce!)

[blackshoe]

I get "could be as short as 2" and similar variants here for "short club". The one pair here (in their 80s) who always plays Precision alerts 1♦, apparently on the grounds that it's limited to 15 HCP (though they don't alert the similarly limited major openings).

I get "weak" when a weak 2 is opened. Sometimes I get "weak" or "preemptive" for a WJS not in competition. Announcements, not explanations of alerts.

I've given up trying to get players to change, or trying to get the TD to do anything about it.

[mycroft]

I am willing to live with "could be as short as X" for "could be short", mostly because if they don't tell me, I ask - and because it is important, the difference between 2 and zero. My partner for years Alerted 1D because that's what he had to do back when he learned; he now Announces, but it wasn't a big deal.

Having said that, Announcement creep does bother me, too.