[iandayre]

Often when I look at results where there were one or two top results on a board, it comes not from good bidding or play, but very bad bidding that somehow induces GIB to go off the rails. Sometimes it is the masterminders who open 1NT with voids, don't show their major (even 5 cards) after Stayman, etc. But often it is just novice errors that do the job - here's an example.

http://tinyurl.com/kfgj3ja

Two people jumped back into this live auction with 1NT opposite a passed partner on the minimum S hand. Obviously a novice error. One can understand why GIB N next bid 3NT, certainly not a great bid, but I get it. What I can't imagine is how this auction managed to induce GIB E to bid 4♠.

Uday?? This unfortunately is not a unique or rare exception, this type of thing happens all too often.

[steve2005]

What's even funnier is the description for correction East North 4♠ bid actually is pretty close to North's hand. So, Gib is designed to bid hopeless 4♠ surely without a fit for partner when 3N doesn't look like it will make if South Gib has their bids.

[Bbradley62]

steve2005, on 2014-November-27, 14:25, said:

What's even funnier is the description for North 4♠ bid actually is pretty close to North's hand. So, Gib is designed to bid hopeless 4♠ surely without a fit for partner when 3N doesn't look like it will make if South Gib has their bids.

North didn't bid 4♠. Maybe East bid 4♠ expecting it to be a reasonable sacrifice (since his partner did show support) against a vulnerable game by NS?

Further comments/questions about the auction:

Why isn't this 1NT rebid 18-19? Wouldn't 20-21 have opened 2N?

If 2♦ shows spade support, why does West make this bid?

Nice double, North!

[iandayre]

I have come to the conclusion that, at least when it comes to bidding, GIB does not understand that there are only 40 HCP in the deck. It sees its own hand, gives full credence to partner's bidding, but apparently is also willing to believe that the opponents have full values for their bids, even when all of those suppositions cannot possibly be true.

[cloa513]

iandayre, on 2014-November-27, 13:54, said:

Often when I look at results where there were one or two top results on a board, it comes not from good bidding or play, but very bad bidding that somehow induces GIB to go off the rails. Sometimes it is the masterminders who open 1NT with voids, don't show their major (even 5 cards) after Stayman, etc. But often it is just novice errors that do the job - here's an example.

http://tinyurl.com/kfgj3ja

Two people jumped back into this live auction with 1NT opposite a passed partner on the minimum S hand. Obviously a novice error. One can understand why GIB N next bid 3NT, certainly not a great bid, but I get it. What I can't imagine is how this auction managed to induce GIB E to bid 4♠.

Uday?? This unfortunately is not a unique or rare exception, this type of thing happens all too often.

Its West's bizzaro bid that induces East's craziness- its not totally terrible assuming North has long minor.

[helene_t]

iandayre, on 2014-December-04, 12:53, said:

I have come to the conclusion that, at least when it comes to bidding, GIB does not understand that there are only 40 HCP in the deck. It sees its own hand, gives full credence to partner's bidding, but apparently is also willing to believe that the opponents have full values for their bids, even when all of those suppositions cannot possibly be true.

It is best in that situation to trust partner. Opps might be playing a funny system but GIB assumes opps to play the GIB system. If an opp makes a Polish 1NT overcall which GIBs interpret as 15-18, there could easily be 50 HCPs in the deck. The best GIB can do, then, is to trust partner.

[iandayre]

helene_t, on 2014-December-05, 05:16, said:

It is best in that situation to trust partner. Opps might be playing a funny system but GIB assumes opps to play the GIB system. If an opp makes a Polish 1NT overcall which GIBs interpret as 15-18, there could easily be 50 HCPs in the deck. The best GIB can do, then, is to trust partner.

I agree with what you say, but look at this hand. There is nothing about the bidding that indicates that the opponents can make 3NT or that you can make 4S.

[1eyedjack]

iandayre, on 2014-November-27, 13:54, said:

Sometimes it is the masterminders who <snip> don't show their major (even 5 cards) after Stayman

Actually, on Bayesian principles, the more cards that you have in excess of 4, the greater the potential benefit of denying 4 cards on enquiry from partner.

If you have say 6 Spades and 2 Hearts and partner Staymans you in an uncontested auction, the overwhelming likelihood is that partner has 4 Hearts and is not the least bit interested in how many Spades you hold. In contrast, the opponents are always intensely interested in how many Spades you hold, and by showing fewer than 4 when you actually hold more than 5 can derail the defence utterly. That has nothing to do with masterminding, but is simply an intelligent manipulation of probability theory. Opening 1NT with a 6 card major in the first place, well that could be masterminding, of course. But having done so, it behoves you to follow it up with the route most likely to capitalise on the tactic.

Eventually, of course, the opponents (other than GIB) may become familiar with your tendency to deny 4M when you hold 6, especially when sitting opposite an ethical human partner who alerts it, and then the benefits get wiped out rather quickly. Not dissimilar to opening the weaker minor when your "system" (ahem) is to open the better.

[iandayre]

1eyedjack, on 2014-December-05, 14:17, said:

Actually, on Bayesian principles, the more cards that you have in excess of 4, the greater the potential benefit of denying 4 cards on enquiry from partner.

If you have say 6 Spades and 2 Hearts and partner Staymans you in an uncontested auction, the overwhelming likelihood is that partner has 4 Hearts and is not the least bit interested in how many Spades you hold. In contrast, the opponents are always intensely interested in how many Spades you hold, and by showing fewer than 4 when you actually hold more than 5 can derail the defence utterly. That has nothing to do with masterminding, but is simply an intelligent manipulation of probability theory. Opening 1NT with a 6 card major in the first place, well that could be masterminding, of course. But having done so, it behoves you to follow it up with the route most likely to capitalise on the tactic.

Eventually, of course, the opponents (other than GIB) may become familiar with your tendency to deny 4M when you hold 6, especially when sitting opposite an ethical human partner who alerts it, and then the benefits get wiped out rather quickly. Not dissimilar to opening the weaker minor when your "system" (ahem) is to open the better.

Interesting. Perhaps this would be right long-term. Still, I very much enjoy it when one of the players with massive amounts of BBO points gets burned doing this. I remember a recent hand where (is it OK to say the name?) did not show his 5 card H suit after Stayman. His GIB partner did hold 4H and only Axx of S, declarer's weak suit. He was able to cash 9 tricks but got a cold zero when decent play made 11 tricks in H and even poor play could not make less than 10.

[1eyedjack]

iandayre, on 2014-December-07, 13:42, said:

Interesting. Perhaps this would be right long-term. Still, I very much enjoy it when one of the players with massive amounts of BBO points gets burned doing this. I remember a recent hand where (is it OK to say the name?) did not show his 5 card H suit after Stayman. His GIB partner did hold 4H and only Axx of S, declarer's weak suit. He was able to cash 9 tricks but got a cold zero when decent play made 11 tricks in H and even poor play could not make less than 10.

It was probably me. It has certainly happened to me a few times. Not enough times for me to change tactic, although state of the match is also influential. If I am going into board 12 of a 55% rebate on 53% I am more likely to do it than if I have 57% to date.

It is certainly a high-variance tactic.