[p_t_red]

This auction shows a hand that specifically has 6 hearts and 5 spades. GIB was 4-4.
GIBW GIBN -Me- GIBE
Pass Pass Pass 1♣
Pass 1♥ (promises 4+ hearts) Pass 2NT
Pass 3♠ (promises 5+ hearts, 4+ spades) Pass 4♥ (signoff)
Pass 4♠ (promises 6+ hearts, 5+ spades) 4NT
Pass 5♥ Pass 6NT
Pass Pass Pass

GIB's hand was:
♠AT86 ♥AJT8 ♦864 ♣Q3

The correct rebid here is 3NT over 2NT.

Another example (maybe GIB changed Standard (have to check 2/1, but I wouldn't expect it to be different) and forgot to tell everyone):
GIBW GIBN GIBE -ME-
Pass Pass Pass 1♦
Pass 1♥ Pass 2NT
Pass 3♠ Pass 4♥
Pass Pass Pass

GIB's hand was:
♠QJ98 ♥AT87 ♦K65 ♣T6

Normally this sequence promises at least 5 hearts, 4 spades unless GIB is reserving New Minor Forcing for that hand. Still it's pointless to checkback for 4 spades unless GIB has also changed the meaning of 2NT, so that it no longer denies 4 spades.

[manudude03]

p_t_red, on 2011-January-10, 13:13, said:

This auction shows a hand that specifically has 6 hearts and 5 spades. GIB was 4-4.
GIBW GIBN -Me- GIBE
Pass Pass Pass 1♣
Pass 1♥ (promises 4+ hearts) Pass 2NT
Pass 3♠ (promises 5+ hearts, 4+ spades) Pass 4♥ (signoff)
Pass 4♠ (promises 6+ hearts, 5+ spades) 4NT
Pass 5♥ Pass 6NT
Pass Pass Pass

GIB's hand was:
♠AT86 ♥AJT8 ♦864 ♣Q3

The correct rebid here is 3NT over 2NT.

Someone correct me if I'm wrong, but isn't 3S described as "4H 4S 7+points" or something?" It would bid 3D (NMF) if it had 5+ hearts. I do think GiB should just pass 4H, but if it had another king, it would probably be endplayed into bidding 4S since 4NT is probably RKC for H.

[Rain]

3S is described as 4H, 4S, 11-HCP, 7-12 TP, whether or not 1C or 1D was opened. The alert should not be telling you 5+H, 4+S. Please check again and screenshot, then report if it's bugged.
I'm not saying bidding 2NT is the best option. But it is what it is, and you have been warned (via pop up alert) Tweaking this is another story, Uday can comment when free.
------------
GIB plays 2/1, not SAYC.

--------------
I have noticed GIB will never stop at NT if it thinks a suit is unstopped.

[barmar]

Here's another one, although not up in the stratosphere:

#9747 ACBL Robot Duplicate

---

When it couldn't show its club suit because it would be NMF, I guess it defaulted to rebidding its original suit. Was I supposed to bid 2♦ instead of 1NT? That also goes down 2. Luckily I had plenty of company, and a number of players made things worse by bidding 2NT; GIB then decided to show its clubs, but they took preference back to spades and went down even more. So I got a 63% board for this. The two players who won the boards were the ones who avoided rebid problems by opening this 1NT (a point shy AND a singleton!), which GIB passed, and the bots couldn't find the defense that should also set it 2 tricks (they instead let declarer make it).

[Bbradley62]

Rain, on 2011-January-11, 14:26, said:

3S is described as 4H, 4S, 11-HCP, 7-12 TP, whether or not 1C or 1D was opened. The alert should not be telling you 5+H, 4+S. Please check again and screenshot, then report if it's bugged.

OP did not say that the explanation given was 5+H; OP says he wants GIB to bid his way.

[Bbradley62]

p_t_red, on 2011-January-10, 13:13, said:

Normally this sequence promises at least 5 hearts, 4 spades unless GIB is reserving New Minor Forcing for that hand. Still it's pointless to checkback for 4 spades unless GIB has also changed the meaning of 2NT, so that it no longer denies 4 spades.

In GIB's system, and in many humans' systems, 2NT shows a balanced hand too strong to open 1NT but not strong enough to open 2NT, without denying having 4 of any unbid majors.

[Bbradley62]

I suspect that GIB's understanding of the first auction is:
Pass -- 1♣
1♥ (4+H) -- 2NT
3♠ (4+H; 4+S) -- 4♥ (choice of major)
4♠ (H slam interest; first-round S control) -- 4NT (RKC)
5♥ (2 KC w/o ♥Q) -- 6NT
Pass

GIB's hand was:
♠AT86 ♥AJT8 ♦864 ♣Q3

[ahydra]

But with 4H, surely the human would raise hearts directly instead of bidding 2NT? So GIB shouldn't be looking for a ♥ slam without a fit...

If GIB doesn't play checkback, it ought to bid the hearts and spades the other way (1C-1S-2NT-3H) so that even if it hears 3S (3-card support), it can still bid 3NT.

ahydra

[phil_20686]

I honestly think that a large fraction (even a majority) of expert players play 1m-1h-2N-3S as showing 4-4 exactly. With 5 hearts you just bid 3H and wait to see if partner has spades. Obviously it would be different if you played a system where you would rebid 1S with 18-19 bal and 4 spades, but not sure that is really playable.

Not sure how GIB would show a slam try in hearts on this sequence though. What does it think 1d-1h-2n-4c is? Anyone know?

[barmar]

Actually, GIB plays that with 4-5 majors you bid New Minor Forcing.

I suspect it plays that 1♦-1♥-2N-4♣ is Gerber, but I'm not sure.

[helene_t]

It's a little weird to go for a heart slam with a known 4-3 fit. If GIBs bidding makes sense then 4♥ is some kind of slam try for spades.

[Bbradley62]

helene_t, on 2011-April-09, 02:21, said:

It's a little weird to go for a heart slam with a known 4-3 fit. If GIBs bidding makes sense then 4♥ is some kind of slam try for spades.

Bizarre labelling notwithstanding, it was the human player who bid 4♥. If GIB took this as a slam try in ♠, then 4♠ was a signoff.

Can a developer please tell us how GIB interprets this auction, instead of having us speculate? Thanks.

[helene_t]

Bbradley62, on 2011-April-09, 04:40, said:

Bizarre labelling notwithstanding, it was the human player who bid 4♥. If GIB took this as a slam try in ♠, then 4♠ was a signoff.

Yes that's what I mean. GIB took 4♥ as a slam try in spades.