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Gib raise wrongly with wrong explanation

#1 User is offline   lycier 

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Posted 2014-April-08, 03:17



My 2 is a descriptive bid without forcing actually,let pd take prference,only.
but strangely Gib N raise 3,and its explanation is 4+,6 total points.
actually it have only 5 total points.
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#2 User is offline   Stephen Tu 

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Posted 2014-April-08, 08:52

2 spade shows a very strong hand, much stronger than what you held. I agree GIB should not raise 2nd suits on 3 cds though.
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#3 User is offline   barmar 

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Posted 2014-April-08, 13:49

2 is a reverse. A reverse shows at least 17 points when partner has bid, it should be even stronger when partner is silent and both opponents are bidding.

North is too strong to pass, because game is possible if South has a maximum for his bid (imagine a 6-5 with 18-20 HCP); take away one point and he would pass. But he has no sensible bid other than raising spades and playing in the possible Moysian, so that's what he does. This should be playable even if South has minimum for his bid.

#4 User is offline   Stephen Tu 

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Posted 2014-April-08, 16:27

View Postbarmar, on 2014-April-08, 13:49, said:

But he has no sensible bid other than raising spades and playing in the possible Moysian, so that's what he does. This should be playable even if South has minimum for his bid.


- I think 18-20 hcp 5-6 would rebid 3 not 2. One is supposed to bid a bit maniacally with 5-6 even opposite a silent partner.
- I think 3 preference is way more sensible than raising the PROBABLE Moysian. The short hand is getting the tap, let partner rebid 3 if he wants if really 5-6. GIB in general is far too quick to raise 2nd suits on 3, this should be absolute last resort.
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#5 User is offline   1eyedjack 

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Posted 2014-April-08, 22:04

I think that 2S is a reasonable bid with a human partner and appropriate agreements. But we have to accept for now GIB system. But then 3D by N is best. I prefer pass of 2S to raising. A remote possibility of missing nv game should be weighed against converting plus to minus.
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

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Masterminding (pron. mPosted ImagesPosted ImagetPosted Imager-mPosted ImagendPosted Imageing) tr. v. - Any bid made by bridge player with which partner disagrees.

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#6 User is offline   Bbradley62 

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Posted 2014-April-09, 09:02

Same hand, but different topic... Is West too weak for 2N over 1?
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#7 User is offline   barmar 

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Posted 2014-April-09, 10:02

View PostBbradley62, on 2014-April-09, 09:02, said:

Same hand, but different topic... Is West too weak for 2N over 1?

Yes, because of the vulnerability. It requires 12 total points when white, 15 total points when red.

#8 User is offline   Bbradley62 

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Posted 2014-April-09, 10:59

View Postbarmar, on 2014-April-09, 10:02, said:

View PostBbradley62, on 2014-April-09, 09:02, said:

Same hand, but different topic... Is West too weak for 2N over 1?
Yes, because of the vulnerability. It requires 12 total points when white, 15 total points when red.

Ok, thanks. I just haven't figured out when GIB considers vulnerability and when he doesn't.

GIB System notes said:

Notes
• Vulnerability does not affect opening/overcall decisions. GIB seems to consider vulnerability and form of scoring only when thinking about leaving in a double for penalties, and other competitive decisions (they get used when performing simulations and estimating the expected value of different outcomes)

Edit: Then I also guess that GIB has a very small range for Unusual NT when Vulnerable:

GIB System notes said:

Competitive Auctions
* Unusual NT (GIB only does Unusual NT with intermediate hands, xx-KQxxxx KQxxx for example)

This post has been edited by Bbradley62: 2014-April-09, 11:05

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#9 User is offline   barmar 

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Posted 2014-April-09, 11:36

There's no general rule about when vulnerability is considered, it's something we can choose to put into an entry in the bidding database. I think it was rarely done when that documentation was first written, but over time we've been adding it as needed as part of the ongoing improvement of the bidding system.

However, simulations take it into account automatically, since they make their decision based on the expected scores. So when you use advanced bots, it can affect its decision about whether to make the book bid versus some close alternative.

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