[Siegmund]

Tonight I had this sequence with the bot:

1♦ - 1NT
2NT - 3♦

I expected the bot to have a terribly weak hand, that believed 3D was a safer contract than 2NT was.

The published description of 3♦ was "5+D, 3-H, 3-S, 6-10 HCP, 7+ total points", which seemed oddly fuzzy. Either this bid is game-forcing or it is to play; 6-10 is not a range that makes much sense for it.

The bot came down with
♠A6
♥K6
♦J753
♣J8643

And I was the only table not in 3NT, of course. (I was also the only person who chose 1D-then-2NT on my side of the table - but I have no complaint's with the 17-18 HCP semibalanced explanation of the 2NT bid, jsut with the bot's reply to it.)

[1eyedjack]

It is a peculiar sequence - almost redundant unless specifically defined to show something just to use up the bid.

With a weak "retreat" from 2N you would presumably have responded 3D to 1D rather than 1N on the previous round.

[biggerclub]

Siegmund, on 2014-July-27, 22:07, said:

Tonight I had this sequence with the bot:

1♦ - 1NT
2NT - 3♦

I expected the bot to have a terribly weak hand, that believed 3D was a safer contract than 2NT was.

The published description of 3♦ was "5+D, 3-H, 3-S, 6-10 HCP, 7+ total points", which seemed oddly fuzzy. Either this bid is game-forcing or it is to play; 6-10 is not a range that makes much sense for it.

The bot came down with
♠A6
♥K6
♦J753
♣J8643

And I was the only table not in 3NT, of course. (I was also the only person who chose 1D-then-2NT on my side of the table - but I have no complaint's with the 17-18 HCP semibalanced explanation of the 2NT bid, jsut with the bot's reply to it.)

I play 3♦ (or any other bid, but particularly 3♦) as forcing here. Bidding anything forces to 3NT.

I should say that not all my partners do. But, and I rarely say this or act like this, they are wrong. The only way to get out below 3NT is to pass 2NT. In particular a weak, distributional hand with ♦ (such as you hypothesize) will make an initial response of 3♦. With GIB's hand, I would likely call 3♣.

[ArtK78]

It is pretty standard for any bid over 2NT to be forcing. That is why some have adopted special methods over the 2NT rebid to get out.

[mike777]

I assume 2nt=invite so:

any bid over 2nt=gf\\

with less pass

[Bbradley62]

Siegmund, on 2014-July-27, 22:07, said:

The published description of 3♦ was "5+D, 3-H, 3-S, 6-10 HCP, 7+ total points", which seemed oddly fuzzy.

I would be interesting to know what differentiates this sequence from an immediate inverted raise.

[helene_t]

An immediate raise can be very weak. I think this sequence is stronger. It is certainly forcing. The actual hand looks like a 3nt bid though

[Bbradley62]

So, an immediate jump is fewer than 6HCP? That seems unGIBlike, but I can't find an example hand.

Funny... I went looking for an un-cut-off explanation of 2N but couldn't find one, because this (perfectly reasonable) South was the only one of the 7 humans who didn't open 1N

But it does appear that North plays 3♦ as forcing, as everyone has said.

[1eyedjack]

After uncontested 1D-1N-2N then as responder I reckon that 90%+ of hands I will be choosing between Pass and 3N. That other 10%- might justify having some mechanism available that involves bidding 3-suit.

However If any suit bid is forcing then you can up it to 98%+, because I see very little profit to be had in bidding 3-minor as a forcing bid.

If I had scraped up a 1N response with a 6 or 7 card Club suit and a borderline pass of 1D, partner raises to 2N, and I have no interest in 3N, I might as well play in a suit contract that has a prayer of making, especially at IMP. So I think that there is a strong case for having 3C non-forcing, even if it does not apply to 3D, and the only reason that the same argument does not apply to 3D is the overlap with a direct raise or jump raise as the case may be.

[Bbradley62]

1eyedjack, on 2014-July-27, 22:38, said:

It is a peculiar sequence - almost redundant unless specifically defined to show something just to use up the bid.

With a weak "retreat" from 2N you would presumably have responded 3D to 1D rather than 1N on the previous round.

Presumably, the specific definition is to show five diamonds to offer a choice of 3N or 5D as the final contract.

[1eyedjack]

Bbradley62, on 2014-July-28, 10:50, said:

Presumably, the specific definition is to show five diamonds to offer a choice of 3N or 5D as the final contract.

Presumably so, and yet 5D just ain't gonna happen. Both partners have already offered NT as a strain. After which is anyone really going to try to land on that pinhead?

[Bbradley62]

If the auction goes 1♦-1N-2N-3♦, responder has not really "offered NT as a strain"; he has made a convention bid of that strain to allow him to make a future description of his hand. If opener's 19HCP is something like Jx, AQx, AQxxx, AQx he very well may prefer 5♦.

[1eyedjack]

1N is non-forcing. If that does not offer a strain, what does?

I agree that on the hand that you give, there are hands where 5D is better than 3N. I also think that investigating that possibility is (a) likely to take you beyond 3N on hands where 3N ends up right, and (b) likely to give info to oppo that will allow them to defeat 3N where blasting it would let it through on a significant number of hands.

Open to arguments, mind.

[steve2005]

1eyedjack, on 2014-July-28, 13:04, said:

1N is non-forcing. If that does not offer a strain, what does?

I agree that on the hand that you give, there are hands where 5D is better than 3N. I also think that investigating that possibility is (a) likely to take you beyond 3N on hands where 3N ends up right, and (b) likely to give info to oppo that will allow them to defeat 3N where blasting it would let it through on a significant number of hands.

Open to arguments, mind.

Agree, but would add 5♦ being the right spot against the odds and really against the odds assuming this is matchpoints.

[Siegmund]

So I guess this really comes down to my usual GIBberish complaint, wishing the bots would be explicit about what they intend as forcing. Some time ago the line "forcing to 3n" got added to FSF explanations. The same might be handy in a few other places.

If 3D IS going to be forcing, it does still need some kind of definition added to it, so I know what the difference between 3D,3H,3S,3N by responder is (without discussion I would take 3M as "I have this major stopped but am afraid of the other" - not sure I'd ever make that bid in real life for fear of helping the opps find the right lead though.)

I can live with not having non-GF escapes (though I WOULD like 1D-1N-2N-3C to be to play), since GIB isn't nearly as fond of cute 4-HCP responses as most humans.