[ggwhiz]

All auctions are free run

1♥ - 1♠
2nt - 3♣
3♦

1♥ - 1♠
1nt - 2♣
2♦

1♦ - 1♠
1nt - 2♣
2♦

1♣ - 1♠
1nt - 2♣
2♦

All of the club bids by responder are artificial checking back for majors and alerted.

All of the (last) diamond bids are artificial, none of the above as to major suit length. Are all or just some of these diamond bids alertable?

I'm in the ACBL but curious as to how EBU or others handle this too.

[WellSpyder]

I can't see any reason why these wouldn't all be alertable in the EBU.

[RMB1]

WellSpyder, on 2017-January-24, 11:37, said:

I can't see any reason why these wouldn't all be alertable in the EBU.

All the club check-back bids and the final diamond bids.

[barmar]

I can't think of any reason why they wouldn't all be alertable in ACBL as well.

The Alert Procedures says that most conventional calls require alerts, then lists 7 categories of common conventions that are excluded. This isn't among them. It says that the list isn't exhaustive, but doesn't give any guidelines about other excluded conventions, so I presume the intent is that they should be similar to the ones listed. These checkbacks are not similar at all.

Is there some reason you thought they might not be alertable?

[sanst]

All conventional bids/special partnership understandings below 4♣ are alertable in Holland, so each and every one of these calls should be alerted. That's also the case when playing under WBF alerting rules.

[Zelandakh]

The third one is the only interesting case. If you are playing 2/1 and have the agreement that Opener rebids 2♦ in the auction 1♦ - 2♣ with any hand of 4+ diamonds and no 4 card major, would that be natural or conventional? Case 3 is actually similar in that the 2♦ call confirms that Opener holds real diamonds for their opening, so could be considered natural. The other 3 are clearly alertable and do not really need to be discussed.

[barmar]

Zelandakh, on 2017-January-25, 04:13, said:

The third one is the only interesting case. If you are playing 2/1 and have the agreement that Opener rebids 2♦ in the auction 1♦ - 2♣ with any hand of 4+ diamonds and no 4 card major, would that be natural or conventional? Case 3 is actually similar in that the 2♦ call confirms that Opener holds real diamonds for their opening, so could be considered natural. The other 3 are clearly alertable and do not really need to be discussed.

The OP said that all the final diamond bids were artificial, merely denying major holdings. However, if the pair plays the common style where opening 1♦ can be a 3-card suit only when the shape is 4=4=3=2, any bid that denies a 4-card major automatically confirms 4+ diamonds.

Is a bid considered natural if it's merely coincidental that it happens to be the same suit where the bidder holds length? If hearts are the agreed suit, is a 5♥ response to Blackwood "natural"?

[pran]

barmar, on 2017-January-25, 09:53, said:

The OP said that all the final diamond bids were artificial, merely denying major holdings. However, if the pair plays the common style where opening 1♦ can be a 3-card suit only when the shape is 4=4=3=2, any bid that denies a 4-card major automatically confirms 4+ diamonds.

Is a bid considered natural if it's merely coincidental that it happens to be the same suit where the bidder holds length? If hearts are the agreed suit, is a 5♥ response to Blackwood "natural"?

Certainly not. The 5♥ bid in this situation means (by agreement) that the bidder holds two aces, not that he holds any particular length in hearts.

[Zelandakh]

barmar, on 2017-January-25, 09:53, said:

Is a bid considered natural if it's merely coincidental that it happens to be the same suit where the bidder holds length? If hearts are the agreed suit, is a 5♥ response to Blackwood "natural"?

Clearly not but do you not see a difference between a heart call that shows "2 or 5 key cards" and a diamond call that shows "4+ diamonds, 0-3 hearts, 0-3 spades"? It is a matter of semantics whether this specific 2♦ call is described as natural or not. The main reason it is seen as artificial is that it fits into a wider artificial convention. Taken in isolation, the sequence itself certainly qualifies as natural. Whether the additional negative connotations qualify as alertable would then depend on local regulations. That is why this sequence is more interesting, it basically qualifies as alertable or not depending on how the pair choose to describe it. The problem with alerting this and using the description given above is that it hides the fact that real diamonds are being shown from the opps and many will not get that if it is not explained to them. That strikes me as more misleading than not alerting at all during the auction and explaining the negative connotations before the opening lead. Alerting and explaining the call in full should work out just fine as well of course.

[barmar]

Compare sequences 3 and 4. In both cases, the 2♦ bid has essentially the same meaning: something like 2-3 ♠ 2 ♥ (or 1-2 if you would rebid NT with a singleton in partner's suit). The length in minors is not part of the meaning of 2♦, but merely a consequence of these constraints and your agreements about your shape for opening 1♣ vs. 1♦. If you happened to open 1♦, these consequences mean that the response to the checkback will happen to be natural. But it seems wrong to call this "natural" if you would give the exact same response when you'd opened 1♣ and didn't have length in diamonds.

[Zelandakh]

barmar, on 2017-January-25, 15:34, said:

The length in minors is not part of the meaning of 2♦, but merely a consequence of these constraints and your agreements about your shape for opening 1♣ vs. 1♦.

This is really the point here isn't it? We know these agreements but the opps probably do not. If we alert this then I think it is important to mention the "natural" side of the call in the description. The alternative, not alerting immediately but using the delayed alert process to describe the negative connotations in the majors seems to me to do just as good a job. This is a tricky one because it might affect the opps' agreements - we might play double of an artificial (could be 3) 2♦ as diamonds and double of a real (4+) 2♦ as a light takeout. Admittedly this is the third round so probably not but if you were an opp, would you not find the information about diamond length the more useful during the auction providing you got the full description before the opening lead, particularly given that practically every other possible meaning of 2♦ here would also be alerted?

[barmar]

Zelandakh, on 2017-January-26, 03:04, said:

This is really the point here isn't it? We know these agreements but the opps probably do not. If we alert this then I think it is important to mention the "natural" side of the call in the description. The alternative, not alerting immediately but using the delayed alert process to describe the negative connotations in the majors seems to me to do just as good a job. This is a tricky one because it might affect the opps' agreements - we might play double of an artificial (could be 3) 2♦ as diamonds and double of a real (4+) 2♦ as a light takeout. Admittedly this is the third round so probably not but if you were an opp, would you not find the information about diamond length the more useful during the auction providing you got the full description before the opening lead, particularly given that practically every other possible meaning of 2♦ here would also be alerted?

They heard the opening 1♦ or 1♣ bid (and there was presumably no alert or "could be short" announcement suggesting that it has an unusual shape) as well as the 1NT rebid. They should be able to make the same inferences we are in the discussion. There's no new information about diamond length in the 2♦ bid.

But the opponents need an alert of 2♦ to tell them that it denies certain lengths in the majors, and from that they can make this inference about diamond length.

[Zelandakh]

barmar, on 2017-January-26, 10:14, said:

They heard the opening 1♦ or 1♣ bid (and there was presumably no alert or "could be short" announcement suggesting that it has an unusual shape) as well as the 1NT rebid. They should be able to make the same inferences we are in the discussion. There's no new information about diamond length in the 2♦ bid.

But the opponents need an alert of 2♦ to tell them that it denies certain lengths in the majors, and from that they can make this inference about diamond length.

Strange, I thought we were meant to explain all aspects of a call when asked including negative inferences. I might feel a little frustrated if I have to ask you 20 questions to get at all of the relevant information. I wonder who the TD would charge time penalties to in such a case.

[barmar]

Zelandakh, on 2017-January-27, 03:18, said:

Strange, I thought we were meant to explain all aspects of a call when asked including negative inferences. I might feel a little frustrated if I have to ask you 20 questions to get at all of the relevant information. I wonder who the TD would charge time penalties to in such a case.

You aren't required to explain information generally known to bridge players. If someone has denied 3+ spades and 4+ hearts (or vice versa), anyone with basic understanding of the game knows that they have at least 4 cards in one of the minors, obviously the minor they opened unless they're playing short minor openings (which they would already have alerted or announced).