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Rediculous defensive mistakes

#1 User is offline   lycier 

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Posted 2017-February-22, 17:22



1- Rediculous definsive mistakes.
2- Obviously, 4H is a descriptive mistake.
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#2 User is offline   m1cha 

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Posted 2017-February-22, 23:00

View Postlycier, on 2017-February-22, 17:22, said:

1- Rediculous definsive mistakes.
2- Obviously, 4H is a descriptive mistake.

Interesting. GIB seems to be very fond of bidding 4 after an initial 1NT. You may have seen my similar topic here: 11 + 12 = 26: the limit raise to full game.

I believe however that your case is a hand evaluation problem rather than a desriptive mistake. The raise to 4 should actually have 4 cards, so the label is correct. But GIB sometimes raises with 3-card trump support instead of 4 when there is no better bid; it's a kind of "smallest lie" and also okay so far. After having bid 1NT based on HCP, probably, it now sees the fit and finds a great hand with only 6 losers and a void, it seems right to bid full game. But GIB overlooks two problems. Firstly, playing in a 7-card fit instead of an 8-card fit, the hand should be down-valued. GIB fails to do this. Secondly, the void in partner's longest suit isn't worth much, if anything. It just means that the opponents have many cards in that suit and it may be impossible to play that suit high. Particularly, one may add, in a 7-card trump fit. Strongly overrating it's hand, East lands in a contract that should go down by 3.


Oh, I just see perhaps you mean the "3+ " part in the label. That is interesting indeed. One should check what a double over 2 would have meant. I believe it should be a penalty double; but if it would have been a take-out double, "pass" in this situation might imply "3+ ". This is just my attempt of an explanation.

As to the defense, I don't know why GIB played this way. Perhaps it found hands where East's diamonds got high if North plays the honors. Perhaps it played West for 5431 and thought you'd ruff anyway as South.
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#3 User is offline   lycier 

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Posted 2017-February-23, 17:18

View Postm1cha, on 2017-February-22, 23:00, said:


I believe however that your case is a hand evaluation problem rather than a desriptive mistake.


Very good, I agree.
However, I suggest that we would better start dealing with such sensitive issues carefully.
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#4 User is offline   johnu 

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Posted 2017-February-24, 11:25

View Postm1cha, on 2017-February-22, 23:00, said:

Oh, I just see perhaps you mean the "3+ " part in the label. That is interesting indeed. One should check what a double over 2 would have meant. I believe it should be a penalty double; but if it would have been a take-out double, "pass" in this situation might imply "3+ ". This is just my attempt of an explanation.


It's hard to believe that a double of 2 would be anything other than a penalty double, but who knows with GIB. Takeout to hearts since opponents have bid clubs and diamonds and opener had a chance to show hearts but didn't?
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#5 User is offline   m1cha 

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Posted 2017-February-24, 22:16

View Postjohnu, on 2017-February-24, 11:25, said:

It's hard to believe that a double of 2 would be anything other than a penalty double, but who knows with GIB. Takeout to hearts since opponents have bid clubs and diamonds and opener had a chance to show hearts but didn't?

I really wanted to know that now, and checked. In addition to what the first double shows, in round 3 East can bid:
X: 2+ → so it's a penalty double indeed, good;
pass: 3+ ; no suitable bid;
2: 4+ ;
2: 1;
none of them promising additional strength. I have not found a bid for a 0-3-1-9 distribution but that doesn't matter because South promised rebiddable . (All bids of at any level imply a "fit".)
Anyway, the "3+ " in the 4 label is indeed from the pass in the previous round. Why it's there will probably remain a mystery.* Strictly speaking - as an interesting side point - pass in round 3 should logically never happen because all hands that qualify for a pass also qualify for a double, so the "no suitable bid" part is an impossibility.

*EDIT: Okay, let me try some conspiration theory assuming (I have wondered before if this is true but I am not sure at all) that whenever GIB has two similar bids available, it will choose the one that is more restrictive in order to describe the hand more precisely. I will also assume that originally the pass did not promise diamonds and I also restrict myself to those hands that do not qualify for a call of 2 or 2. The remaining hands always contain several cards with some rare exceptions containing tons of . With these hands GIB would then always double. But someone might have complained that doubling at the 2 level is not always a good idea, and someone else may have wondered how to make GIB pass - and found out that the way to make GIB pass is to make the pass call more restrictive than the double by demanding that pass contain 3+ - and there we are. This work-around had the desirable effect of making GIB pass instead of double through the paradoxical situation that a pass requires more cards in opponents' suit than a penalty double. GIB would still double with exactly 2 cards in but that's irrelevant because it almost never happens.
Will try to check the latter, but not today. Stay tuned! ;)
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#6 User is offline   johnu 

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Posted 2017-February-25, 06:54

View Postm1cha, on 2017-February-24, 22:16, said:

I really wanted to know that now, and checked. In addition to what the first double shows, in round 3 East can bid:
X: 2+ → so it's a penalty double indeed, good;
pass: 3+ ; no suitable bid;
2: 4+ ;
2: 1;
none of them promising additional strength.


Double shows only 2+ diamonds??? while double of 2in passout position showed biddable clubs? C'mon GIB, you can do better.

Pass shows 3+ diamonds? If you say so GIB :rolleyes:

2 with 1 card spade support. I checked and it isn't April 1 but nice try GIB :P
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#7 User is offline   m1cha 

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Posted 2017-February-25, 21:04

Bingo!

View Postm1cha, on 2017-February-24, 22:16, said:

This work-around had the desirable effect of making GIB pass instead of double through the paradoxical situation that a pass requires more cards in opponents' suit than a penalty double. GIB would still double with exactly 2 cards in

I believe my thesis was correct. GIB indeed doubles with exactly a doubleton . I exchanged 9 and 9 in the following hand:



(Never mind the bidding by South, that was just necessary to complete the bidding sequence.)

I suggest if the double of 2 were corrected to "biddable " and "3+ " removed from the pass, we'd have a reasonable penalty double as well as a reasonable pass.

View Postjohnu, on 2017-February-25, 06:54, said:

2 with 1 card spade support. I checked and it isn't April 1 but nice try GIB :P

Well I can find some logic in this. Because with a spades doubleton East could bis 2 in the second round (at any point range, actually, if the pass by West shows a weak hand). Failing to do so denies that doubleton, so that 2 in the third round can show exactly a singleton; upon which West might run with just a 5-card suit. (Just to make one thing clear: I'm suggesting that, given the circumstances, this is a reasonable natural meaning of that bid; I'm not suggesting that actually using that bid were a good idea. ;) )
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