[Ranmit]

Q regarding what is permissible under basic+ chart (lower level flights at NAP/GNT etc at the NABCs).

1. Are 'one under' good raises allowed (Ex: 1S 2H - showing good raise in S but not GF?)
2. Artificial 2NT opener showing 5-5 in 1 known + 1 unknown suit?
3. If playing strong club opening with 1D opening showing 12-15 pts with as few as 2 diamonds if balanced: an artificial 1H response to 1D showing 5-11 pts, need not say anything about hrts?
4. (Edited to add): Are there any restrictions on opener or responder's rebids? (I think not)

Thanks!

[johnu]

In my reading of the charts:

1. One under raise - Not allowed. Under allowable responses, this is not natural (1) and not game forcing (2). This would be allowed if it was a jump to the 3 level (or 2♠ over 1♥) (7).

2. 2NT showing a known and unknown suit - Not allowed. Under allowed opening bids, exception is if 2NT shows a very strong hand (7), or if 5-4 or better, both suits are known, average strength (8), or shows both minors (10)

3. 1♥ artificial response to 1♦ - Not allowed unless game forcing (2).

[Ranmit]

johnu, on 2025-August-02, 16:54, said:

In my reading of the charts:

1. One under raise - Not allowed. Under allowable responses, this is not natural (1) and not game forcing (2). This would be allowed if it was a jump to the 3 level (or 2♠ over 1♥) (7).

2. 2NT showing a known and unknown suit - Not allowed. Under allowed opening bids, exception is if 2NT shows a very strong hand (7), or if 5-4 or better, both suits are known, average strength (8), or shows both minors (10)

3. 1♥ artificial response to 1♦ - Not allowed unless game forcing (2).

Thanks. Also, are there any restrictions on opener's and responder's rebids? (I think not, but wanted to confirm).

[mycroft]

"Beginning with the Opening Bidder’s second call, all calls are allowed by both pairs."

And I don't read the chart at all differently from JohnU (except to add that transfer responses after 1suit-X are fine; but as he said, not legal if RHO passes or overcalls).

Note that your 2NT isn't legal on the Open Chart either, unless it guarantees Average values (Ro19). Two *known suits* is fine.

[Ranmit]

Another question on this topic:

The basic+ chart says, regarding allowed responses - "7. An Artificial jump response showing a raise (of any strength) of Opener’s Natural
opening bid is allowed"

So 1H 3C = limit raise with 3+ hearts is allowed.

But what if opponents bid 2D? Then 1H (2D) 3C is no longer a 'jump' response - is it then allowed as a 3 card limit raise for opener's major?

[blackshoe]

Nope.

[jillybean]

 blackshoe, on 2025-September-19, 13:03, said:

Nope.

Where does it say that?

[Ranmit]

Also (sorry for asking questions in this disjointed way) - in standard vanilla 2/1, after a 1D opener, if responder has < 4 cards in each Major and 6-9 points, the default bid is 1NT. (Since 2D is usually inv minor 10+ and 2C is GF). So this 1NT response could be with shortness (Ex: 1/3-4/5 or 1/3/3-6 distribution).
But my reading of the Basic+ chart suggests that this is not allowed, since a NT response with shortness is not 'natural'? Is that correct?

For context, this is for preparation for NAP. And at least this above point seems very weird. It would feel unfair if we change our bidding system to be within the rules, only to find that most people just play this 1D-1NT anyway, given it is so common, and directors are not going to disqualify half the field?

[akwoo]

A 1N response to 1D that could be on, say, a 1=3=3=6 hand is allowed, because it suggests playing in 1N and hence is natural. (See the last part of the definition of "Natural".)

Transfers after 1M-overcall are legal, under item 13 of "Overcalls and Competitive Bids": "After an opening bid and an overcall or double, any call (by either side) showing length in a known suit." So are transfers to NT, under item 14. Note this might not be okay if your transfers could be purely lead directing. This also says that 1H-(2D)-3C showing 3 card support in hearts is legal.

[barmar]

jillybean, on 2025-September-19, 14:47, said:

Where does it say that?

In Basic and Basic+, anything not allowed is prohibited. If it doesn't say this is allowed in interference, it isn't allowed.

[Ranmit]

akwoo, on 2025-September-19, 17:01, said:

A 1N response to 1D that could be on, say, a 1=3=3=6 hand is allowed, because it suggests playing in 1N and hence is natural. (See the last part of the definition of "Natural".)

That makes sense - thanks! I missed that last part.

akwoo, on 2025-September-19, 17:01, said:

Transfers after 1M-overcall are legal, under item 13 of "Overcalls and Competitive Bids": "After an opening bid and an overcall or double, any call (by either side) showing length in a known suit." So are transfers to NT, under item 14. Note this might not be okay if your transfers could be purely lead directing. This also says that 1H-(2D)-3C showing 3 card support in hearts is legal.

Can you let me know where this (1H-(2D)-3C showing 3 card support) is allowed? Point 13 says it must show Length in a known suit, with Length = 4+ cards?

[blackshoe]

jillybean, on 2025-September-19, 14:47, said:

Where does it say that?

In the section of the Basic+ chart on competitive bidding, where this bid does not appear (and is therefore not legal on this chart).

[mycroft]

I would be surprised if the intent was to not allow "known 8-card fit" in "bid that shows Length in a specific suit", but according to the letter of the regulations (where Length is "4+ unless otherwise stated", and it's not stated here) it's not legal.

Having said that, I would ask the director of the NAP about that specific situation. You may find a stickler for the letter of the Law, or someone who reads it the way I would (like to). Better to know *before the director call*, yes?

Worst case, the director says the same thing there I am here, and goes and checks with somebody who can give a Conventions Committee answer.

[barmar]

mycroft, on 2025-September-20, 11:46, said:

I would be surprised if the intent was to not allow "known 8-card fit" in "bid that shows Length in a specific suit", but according to the letter of the regulations (where Length is "4+ unless otherwise stated", and it's not stated here) it's not legal.

Showing a fit falls under the calls that "show a raise in opener's suit".

[mycroft]

Of which there is no allowance for an Artificial, non-jump raise on the Basic+ chart.

Unless it's GF.

Unless it's a Cuebid.

Or a double, I guess (transfers/1M-2x starting with double?)

But the only allowance for 3♣ specifically being a limit raise would be "Length in the suit".

Hence my "not legal, but could easily be a misstatement rather than intended."