[Bbradley62]

I may have helped create this situation... It used to be that direct-seat bids in competition were seen as invitational, not simply competitive, e.g.:
http://www.bridgebas...__1#entry461348
http://www.bridgebas...in-competition/
Now, it appears that these bids are strictly competitive and the invitational range may have disappeared.

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All ten Souths faced the decision of what to bid over 3♦; four bid 3♥, but I didn't because the description looked strictly competitive, not invitational, with the maximum of 15 total points. But, bidding 4♥ instead was too much. I didn't write down the description, and none of the Souths chose it, so I don't have it, but I think it was 18-22 total points.

It appeared that the only bid available for the invitational strength (16-17 total points) was double, which I was hoping would be read as a general-strength bid. I still don't know how it was read, but I was the only one of the 10 players who tried it... I don't honestly know what I would have done in the North seat...

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The four of the ten Souths passed 3♦, possibly thinking they were too strong for 3♥ but not strong enough for 4♥, and they got to defend 3♦ undoubled.

How "should" the auction go after 3♦?

[barmar]

The problem is that you're supposed to open 1NT with that hand. The whole reason to open 1NT with 5-card majors is to avoid rebid problems like this. By opening 1♥, you've denied holding a balanced hand in the 15-17 range, so all your rebids show something stronger or weaker.

[Bbradley62]

I guess that's a modern style that I will simply have to learn. Funny that none of the ten Souths in this tournament thought of it. Thanks for the explanation.

[Bbradley62]

Bbradley62, on 2011-November-07, 08:00, said:

I guess that's a modern style that I will simply have to learn. Funny that none of the ten Souths in this tournament thought of it. Thanks for the explanation.

PS: Of course, this doesn't change the fact that I could have been 3613, and therefore opening 1NT would have been bad. In this case, I'd still be facing a decision between rebidding 3♥ (12-15 total points) or 4♥ (18-22 total points). I completely understand that with only two choices I must either go or not, there is no in-between, but I think the two stated ranges should include 16 and 17 somewhere.

[barmar]

In most cases you'd have a game try available. You ran into one of the auctions that Maximal Double (aka Game Try Double) was invented for, but GIB doesn't play it. This is the same hole in the system that human players also have if they don't play this convention (and I suspect most don't).

Human players solve this problem by making a judgement call, either downgrading or upgrading the hand. The equivalent in GIB is simulations. I moved the little club into hearts and asked GIB what it would bid; it opened 1♥ and jumped to 4♥ over 3♦ in all simulation runs in IMP mode, and split 5/4/2 between 3♥, 4♥, and Pass in matchpoint mode (at IMPs you stretch to bid vulnerable games). However, when I reduced the quality of the heart suit, but kept the overall shape and strength the same (and even adding a point), it was less aggressive at IMPs as well. The simulations told it what human players know intuitively: it's better to have your high cards in your long suits, so upgrade those hands.

All bidding systems have holes, it's the nature of the game. It's simply not realistic to expect us to compile a bidding database equivalent to Meckwell's hundreds of pages of system notes. When you have judgement/simulations, there are diminishing returns to plugging all the holes in the system.

[cloa513]

Anyway 4♥ only just makes anyway as West should lead a low heart and win the A♦ and lead the A♥ and another heart, then you lose 3♦ and a heart, it weren't the incredibly lucky fact that N-S have those three top honours so with the hand as given you still make it because of the the lucky fact that West has one club. Really 4♥ making is lucky rather than likely.

[barmar]

Yeah, the ♦QJx should be downgraded with West bidding ♦. I wouldn't be thinking about trying for game with that hand.

[Bbradley62]

barmar, on 2011-November-07, 00:10, said:

The problem is that you're supposed to open 1NT with that hand. The whole reason to open 1NT with 5-card majors is to avoid rebid problems like this. By opening 1♥, you've denied holding a balanced hand in the 15-17 range, so all your rebids show something stronger or weaker.

Apparently, opening 1♠ doesn't deny holding a balanced hand in the 15-17 range, given the explanation of the 2N rebid below:

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Of the 10 human Souths, 3 passed 2♦, 3 rebid 2♠ and 4 rebid 2N, presumably either ignoring or not previewing the explanation.

[barmar]

You can rebid 2NT with 5224 distribution, which wouldn't open 1NT.

Also, GIB needs an explanation of the 2NT rebid if it comes up, even if most of the hands in the description should have opened 1NT. There's nothing better for this 2NT bid.

[myprac]

barmar, on 2011-November-07, 00:10, said:

By opening 1♥, you've denied holding a balanced hand in the 15-17 range, so all your rebids show something stronger or weaker.

In a previous version, GIB's system specified that 1NT denies a 5-card major. The system card (text version) still says this, but there was an announcement a while back that GIB's system would permit 1NT with a 5-card major and the rollover for an opening 1NT bid says "Could have 5M." When the change was posted, I asked about the criteria for determining whether to bid 1NT or 1M. The answer wasn't entirely clear, but it definitely didn't say or imply that 1NT is required or even preferred for all balanced hands within range, leaving me to conclude you could go either way with these hands based on preference or criteria such as strength and texture of the suit. Can you elaborate on the current thinking concerning these hands as seen in GIB's system?

[barmar]

With 15-16 HCP, GIB will open 1NT. With 17 HCP, it will open the major and rebid 2N, essentially upgrading the hand because of the 5-card suit.

[Bbradley62]

barmar, on 2011-December-09, 14:29, said:

With 15-16 HCP, GIB will open 1NT. With 17 HCP, it will open the major and rebid 2N, essentially upgrading the hand because of the 5-card suit.

Barry: Do you now control the GIB System Notes document? Helpful info like this should almost always be copied-and-pasted to the appropriate place in that document.

[myprac]

barmar, on 2011-December-09, 14:29, said:

With 15-16 HCP, GIB will open 1NT. With 17 HCP, it will open the major and rebid 2N, essentially upgrading the hand because of the 5-card suit.

Okay, not to be critical but just make sure we're clear, if this is true then the earlier comment that a 1♥ opener denies a balanced 15-17 is incorrect. I guess it denies a balanced 15-16, in GIB's mind anyway.

[Bbradley62]

barmar, on 2011-December-09, 14:29, said:

With 15-16 HCP, GIB will open 1NT. With 17 HCP, it will open the major and rebid 2N, essentially upgrading the hand because of the 5-card suit.

Does the rebid the same whether CHO responds 1NT goes 2/1? The explanation of 2N in post #8 above seems to contradict this answer.

[barmar]

Bbradley62, on 2011-December-10, 07:02, said:

Does the rebid the same whether CHO responds 1NT goes 2/1? The explanation of 2N in post #8 above seems to contradict this answer.

I was talking about 1♥-1♠-2NT and 1♠-1NT-2NT. After a 2/1 by a passed hand, 2NT is natural and invitational. With a stronger hand, it will make a game forcing bid or just bid game itself.