GIB Bids 6NT Again

[sm101]

In the Robot Duplicate Tournament #773, Hand #2, I opened 1C, GIB bid 1D, I bid 2N, GIB bid 3C, I bid 3N, GIB bid 6N. We missed 2 aces and went down. I understand that GIB does not use Gerber. If that is the case, then he should not jump to 6N without knowing how many aces we have.

[manudude03]

I wonder why 3NT shows 19 HCP after 2NT showed 18-19. 4NT would be quantitative for most while 4C is natural so it's not so easy to ask for aces. It is only worth a 4NT bid at most though (I guess it simulated that there were 12 tricks more often than not).

 

[hv=http://www.bridgebase.com/tools/handviewer.html?bbo=y&lin=pn|sm101,~~M57282,~~M57280,~~M57281|st%7C%7Cmd%7C4S379KH9JQKDQAC45K%2CS56JH267D56C39TJA%2CS2QH4AD248JKC268Q%2C%7Crh%7C%7Cah%7CBoard%202%7Csv%7Cn%7Cmb%7Cp%7Cmb%7C1C%7Can%7CMinor%20suit%20opening%20--%203%2B%20%21C%3B%2011-21%20HCP%3B%20%7Cmb%7Cp%7Cmb%7C1D%7Can%7COne%20over%20one%20--%204%2B%20%21D%3B%206%2B%20total%20points%20%7Cmb%7Cp%7Cmb%7C2N%7Can%7CJump%20in%20notrump%20--%203-5%20%21C%3B%202-5%20%21D%3B%202-4%20%21%7Cmb%7Cp%7Cmb%7C3C%7Can%7C4%2B%20%21C%3B%204%2B%20%21D%3B%207%2B%20total%20points%20%7Cmb%7Cp%7Cmb%7C3N%7Can%7C3-5%20%21C%3B%202-5%20%21D%3B%202-4%20%21H%3B%202-4%20%21S%3B%2019%20HCP%3B%20%7Cmb%7Cp%7Cmb%7C6N%7Can%7C4%2B%20%21C%3B%204%2B%20%21D%3B%2014-16%20HCP%20%7Cmb%7Cp%7Cmb%7Cp%7Cmb%7Cp%7Cpc%7CH2%7Cpc%7CHA%7Cpc%7CH3%7Cpc%7CH9%7Cpc%7CD2%7Cpc%7CD7%7Cpc%7CDQ%7Cpc%7CD5%7Cpc%7CDA%7Cpc%7CD6%7Cpc%7CD4%7Cpc%7CD3%7Cpc%7CC4%7Cpc%7CCA%7Cpc%7CC2%7Cpc%7CC7%7Cpc%7CH7%7Cpc%7CH4%7Cpc%7CHT%7Cpc%7CHJ%7Cpc%7CS3%7Cpc%7CS5%7Cpc%7CSQ%7Cpc%7CSA%7Cpc%7CS4%7Cpc%7CSK%7Cpc%7CS6%7Cpc%7CS2%7Cpc%7CCK%7Cpc%7CC3%7Cpc%7CC6%7Cpc%7CST%7Cpc%7CHK%7Cpc%7CH6%7Cpc%7CC8%7Cpc%7CH8%7Cpc%7CHQ%7Cpc%7CCJ%7Cpc%7CD8%7Cpc%7CH5%7Cpc%7CC5%7Cpc%7CC9%7Cpc%7CCQ%7Cpc%7CDT%7Cpc%7CDK%7Cpc%7CD9%7Cpc%7CS7%7Cpc%7CCT%7Cpc%7CDJ%7Cpc%7CS8%7Cpc%7CS9%7Cpc%7CSJ%7C]400|300[/hv]

[iandayre]

Very valid points. What about it BBO, why is GIB bidding 6NT here with a 31 HCP max?

 

As for the action after 3C, seems to me that 3NT is the minimum bid. Any suit bid would show interest in a club slam.

[Bbradley62]

As for the action after 3C, seems to me that 3NT is the minimum bid. Any suit bid would show interest in a club slam.

That depends on how North would bid with various strengths and (04)54 shape. Does 3♣ deny a 4M? If not, should 3N deny one? (There needs to be some way of finding 4-4M fit without introducing the suit at the 4 level.)

 

Once you've limited your hand to a balanced 18-19HCP, I don't see how/why you'd need a way to show slam interest opposite 7+ total points.

[iandayre]

That depends on how North would bid with various strengths and (04)54 shape. Does 3♣ deny a 4M? If not, should 3N deny one? (There needs to be some way of finding 4-4M fit without introducing the suit at the 4 level.)

 

Once you've limited your hand to a balanced 18-19HCP, I don't see how/why you'd need a way to show slam interest opposite 7+ total points.

 

Point 1 - I know that the auction 1m-1H-2NT-3S is just 4-4 in the majors with GIB. Presumably it could show a major, if held, over 2NT in the current auction. I suppose it could be 4054 and have a Diamond suit, a club fit AND a major. I don't know what GIB would do over 2NT with that holding, most likely show the major and support Clubs later. That would suggest that 3C does deny a major and there is no need for opener to show a 4 card holding. Therefore 3M is a cue showing interest in a Club slam - see below.

 

 

Point 2 - 7+ does not have an upper limit. The example hand is much better than 7, and I would presume that it could be stronger. It could be a hand good enough to set Clubs as trumps planning to bid Blackwood the next round, or one nearly that good that wants to judge opener's interest in slam.

[Bbradley62]

I disagree with everything you've said (except that it's odd that 3N says 19, not 18-19) and it would be nice to know how GIB actually handles these things.

[steve2005]

I disagree with everything you've said (except that it's odd that 3N says 19, not 18-19, and it would be nice to know how GIB actually handles these things.

Yes why is 3N 19 hcp cant it be 18-19 hcp without a good hand for a minor suit slam with both majors stopped? Without that meaning is it possible to play in 3N with 18 hcp?

 

 

 

 

 

[iandayre]

Yes why is 3N 19 hcp cant it be 18-19 hcp without a good hand for a minor suit slam with both majors stopped? Without that meaning is it possible to play in 3N with 18 hcp?

 

I also dissgreed with 3NT showing 19, it should be the generic response showing little/no slam interest.

 

As for BB's disagreement, I feel confident about my position. Perhaps Stephen Tu will weigh in.

[1eyedjack]

Once you've limited your hand to a balanced 18-19HCP, I don't see how/why you'd need a way to show slam interest opposite 7+ total points.

 

<snip>

 

Point 2 - 7+ does not have an upper limit.

Did you not answer your own question in the same post?

[Stephen Tu]

I think 3♣ should deny 4 cd major. I don't think 3M should show slam interest necessarily; game before slam. Without agreement I'd take it as initially showing concentration of values and perhaps shaky stopper in the other major, not wanting to play in 3nt opposite a small stiff. Wait until 3nt is bypassed before the cues definitely show prime values for slam.

 

I think one major problem on the auction is that 2nt/3nt by GIB still show 2-5 diamonds? Surely 2nt should be 4 diamonds at most and 3nt should probably be assumed 2 diamonds, as I think most hands with 3 diamonds ought to bid 3d over 3c. With less of a fit possible North would probably bid less?

[Bbradley62]

Did you not answer your own question in the same post?

That was my question he was answering, not his own. He lost the "end quote" command, so it's not clear where my post ends and his begins.

[Bbradley62]

I think one major problem on the auction is that 2nt/3nt by GIB still show 2-5 diamonds? Surely 2nt should be 4 diamonds at most and 3nt should probably be assumed 2 diamonds, as I think most hands with 3 diamonds ought to bid 3d over 3c. With less of a fit possible North would probably bid less?

The descriptions of almost all of GIB's NT rebids allow for impossible distribution; it's been my favorite dead horse to beat for a while now. Given that the 2N rebid shows balanced 18-19HCP and that GIB opens 1♦ with 4-4m, 2N shouldn't even include 4 diamonds. 3N over 3♣ should allow for something like AKx, AKx, xxx, KJxx.

[1eyedjack]

I think 3♣ should deny 4 cd major.

I don't agree with this. Unless opener is rebidding 2N with a non-classically-balanced hand (and I don't think that it ever does) then opener has 2-4 Spades, 2-4 Hearts, 2-3 Diamonds and 3-5 Clubs. The explanation shows 2-5 Diamonds but it would have opened 1D with more than 3. Even so, a 5-3 Diamond fit is possible.

 

A fit in either minor is possible, and more likely than a major fit. Sure, a major fit is more important to find, but finding it below 3N remains available after 3C, provided of course that 3C does not deny a major.

 

A fit in a minor can still be found, of course, by responder bidding 3M, but only by venturing beyond 3N. Why tie yourself down like that? If 3M showed something approaching your full shape then I would go with it, but apart from showing 4-5 in M-D it is not particularly descriptive.

[Stephen Tu]

A fit in a minor can still be found, of course, by responder bidding 3M, but only by venturing beyond 3N. Why tie yourself down like that? If 3M showed something approaching your full shape then I would go with it, but apart from showing 4-5 in M-D it is not particularly descriptive.

 

Huh? Having 3c deny major removes considerable ambiguity from the rest of the auction IMO. If you have 4-5 M-D isn't that the most important thing to show? After 1c-1d-2nt-3M-3nt-4c, this shows your pattern very well. If you start with clubs, partner can never really be certain whether your subsequent major bid is a cue bid, probe for 3nt, etc., and your pattern will not be known, he doesn't know you aren't 3154 instead of 4054. If you reserve major bids after 3c to show actual 4 card suit to find 4-4 M fit, then you hamper yourself considerably when responder does have just both minors and is worried about major stoppers and the decision is between 3nt and 5m.

[georgi]

6NT needs 13+HCP at the moment, bidded directly or after new suit on next round, by responder.

 

So 3NT would be fixed to be used with all hands under 12HCP or directly over 2NT if no better contract seems possible which might be hands like 4♦333/44minors 32 or on next round, once there is no major fit found.

 

To be found such major fit thought, GIB needs 5D4M, so with 4D4M, major will prevail always.