GIB Bug?

[skivt]

Today (#7835 bd 11), I dealt (none vul)and my GIB partner held QT954,T,JT76,T64.

 

Auction 2C p 2D p

 

2H X 2S 3C

 

4H p 5H!!!

[Bbradley62]

[hv=lin=pn|skivt,~~M39241,~~M39239,~~M39240|st%7C%7Cmd%7C1S6AH3569JQKAD4C25%2CS78JKH47D23QAC9JQ%2CS459TQHTD67TJC46T%2C%7Crh%7C%7Cah%7CBoard%2011%7Csv%7Co%7Cmb%7C2C%7Can%7CStrong%20two%20club%20--%2019%2B%20HCP%3B%2023%2B%20total%20po%7Cmb%7Cp%7Cmb%7C2D%7Can%7C2D%20bid%20waiting%20--%20forcing%20to%202N%20%7Cmb%7Cp%7Cmb%7C2H%7Can%7COpener%5C%27s%20suit%20--%205%2B%20%21H%3B%2019%2B%20HCP%3B%2023%2B%20tot%7Cmb%7Cd%7Can%7CTakeout%20double%20--%203%2B%20%21C%3B%203%2B%20%21D%3B%202-%20%21H%3B%203%2B%20%21S%3B%2014%2B%20total%20points%20%7Cmb%7C2S%7Can%7C2-%20%21H%3B%20biddable%20%21S%3B%20forcing%20to%203H%20%7Cmb%7C3C%7Can%7C5%2B%20%21C%3B%207-20%20total%20points%20%7Cmb%7C4H%7Can%7Cstrong%20rebiddable%20%21H%3B%2025%2B%20total%20points%7Cmb%7Cp%7Cmb%7C5H%7Can%7C2%20%21H%3B%20biddable%20%21S%3B%206%2B%20total%20points%20%7Cmb%7Cd%7Can%7C5%2B%20%21C%3B%2011-20%20total%20points%20%7Cmb%7Cp%7Cmb%7Cp%7Cmb%7Cp%7Cpc%7CH7%7Cpc%7CHT%7Cpc%7CH8%7Cpc%7CHA%7Cpc%7CHK%7Cpc%7CH4%7Cpc%7CC4%7Cpc%7CH2%7Cpc%7CS6%7Cpc%7CSK%7Cpc%7CS4%7Cpc%7CS2%7Cpc%7CCQ%7Cpc%7CC6%7Cpc%7CC3%7Cpc%7CC2%7Cpc%7CS7%7Cpc%7CS9%7Cpc%7CS3%7Cpc%7CSA%7Cmc%7C9%7C]360|270[/hv]

[1eyedjack]

I sympathise with the sentiments. Even giving South hands consistent with explanations 5H seems ambitious. But South did little to help.

 

Interestingly, you cannot make game, despite that North could have been weaker. He even has an entry. On that basis in some parts of the world South might not qualify to open 2C. Indeed if you rigidly apply GIB's hand evaluation you have 18 total points, one shy of GIB's requirements. That said it is certainly trivial to construct numerous hands for North in which North provides the one required trick for game, where North would pass a 1 opener. You would be relying on opponents to protect, which would have a high likelihood. But then you might not buy it in 4H, so you may want to cut them out.

 

Even having opened 2C you are not assured of an uncontested ride, and the prospect of a contested auction must be cause for concern. Had the opposing sides' trump fits been longer they may have tried harder to buy the contract, and South may be undersandably nervous if North starts doubling for penalties in the expectation of some defensive cards with South.

 

But GIB does not play Texas (I think) allowing for split-strength 4-level pre-empts. So let us accept that while 2C opener is borderline suspect, and perhaps not everyone's choice, it does not rank as the most heinous decision on the hand. It would be a nice feature if after the hand(/tourney?) has ended the user could interrogate what GIB would have chosen for each South decision (with explanations for bids attached).

 

Moving on, the 2H rebid is consistent with the earlier decision to open 2C. It might be instructive to learn what alternatives 3H and 4H would have meant for GIB. I hope that 3H would have been a GF powerhouse. Perhaps solid suit but overall hand stronger than this one. But what of 4H? If that shows a min 2C opener that knows where it wants to play, this may be the rebid of choice. Certainly helps crowd out the oppo.

 

Having chosen 2H rebid we do now have the luxury of seeing how GIB interprets South's 3rd bid of 4H. And this is really where South must take some of the blame. Sensibly or not, GIB expects 25+ total points. South may be borderline to open 2C, but it is nowhere near borderline to qualify for this description. I suspect that 3H is the bid of choice by GIB.

 

If you hover over bids before committing you can see GIB interpretation of each option. You cannot reproduce them in forum postings, but at the table you could see in advance what the different Heart bids would have meant at each of South's turns to bid.

[Antrax]

Moving on, the 2H rebid is consistent with the earlier decision to open 2C. It might be instructive to learn what alternatives 3H and 4H would have meant for GIB.

Nothing, unfortunately. The description is identical to 2♥, except now you're a level higher. Neither sets trump - it's currently impossible to set trumps in GIBberish after a 2♣ opener.

[steve2005]

North has no expectation of a trick in support of south, so I just don't see 5♥ as improving the contract.

 

 

 

 

What about 2♣-2♦-4♥ anyone know the explanation for this bid? that's what I would do if I chose to open 2♣

 

 

 

[Bbradley62]

Indeed if you rigidly apply GIB's hand evaluation you have 18{17} total points, one{six} shy of GIB's requirements.

FYP. (GIB "takes back" the doubleton point for Ax.) But, as you say, total points are not really relevant here.

[Bbradley62]

What about 2♣-2♦-4♥ anyone know the explanation for this bid? that's what I would do if I chose to open 2♣

I like your suggestion, but none of the 28 players in the tournament did it. The vast majority opened 4♥. Those who opened 1♥ got doubled when they got to 4♥, which might have been a top board opposite a slightly different North. Other options were:

[hv=lin=pn|mtt1127,~~M39265,~~M39263,~~M39264|st%7C%7Cmd%7C1S6AH3569JQKAD4C25%2CS78JKH47D23QAC9JQ%2CS459TQHTD67TJC46T%2C%7Crh%7C%7Cah%7CBoard%2011%7Csv%7Co%7Cmb%7C2C%7Can%7CStrong%20two%20club%20--%2019%2B%20HCP%3B%2023%2B%20total%20po%7Cmb%7Cp%7Cmb%7C2D%7Can%7C2D%20bid%20waiting%20--%20forcing%20to%202N%20%7Cmb%7Cp%7Cmb%7C3H%7Can%7COpener%5C%27s%20suit%20--%205%2B%20%21H%3B%2019%2B%20HCP%3B%2023%2B%20tot%7Cmb%7Cp%7Cmb%7C3S%7Can%7C4%2B%20%21S%3B%205%2B%20total%20points%3B%20forcing%20%7Cmb%7Cp%7Cmb%7C4H%7Can%7C19%2B%20HCP%3B%20twice%20rebiddable%20%21H%3B%2023%2B%20total%20%7Cmb%7Cp%7Cmb%7Cp%7Cmb%7Cp%7Cpc%7CH7%7Cpc%7CHT%7Cpc%7CH2%7Cpc%7CHA%7Cpc%7CHK%7Cpc%7CH4%7Cpc%7CC4%7Cpc%7CH8%7Cpc%7CSA%7Cpc%7CS8%7Cpc%7CS4%7Cpc%7CS2%7Cpc%7CS6%7Cpc%7CSK%7Cpc%7CS5%7Cpc%7CS3%7Cpc%7CCQ%7Cpc%7CC6%7Cpc%7CC3%7Cpc%7CC2%7Cpc%7CCJ%7Cpc%7CCT%7Cpc%7CC7%7Cpc%7CC5%7Cpc%7CC9%7Cpc%7CS9%7Cpc%7CC8%7Cpc%7CH3%7Cpc%7CHQ%7Cpc%7CD3%7Cpc%7CD6%7Cpc%7CD9%7Cpc%7CHJ%7Cpc%7CD2%7Cpc%7CST%7Cpc%7CD5%7Cpc%7CH9%7Cpc%7CSJ%7Cpc%7CD7%7Cpc%7CD8%7Cpc%7CH6%7Cpc%7CS7%7Cpc%7CSQ%7Cpc%7CDK%7Cpc%7CH5%7Cpc%7CDA%7Cpc%7CDT%7Cpc%7CCK%7Cpc%7CD4%7Cpc%7CDQ%7Cpc%7CDJ%7Cpc%7CCA%7C]360|270[/hv]

[hv=lin=pn|jjcoca,~~M39262,~~M39260,~~M39261|st%7C%7Cmd%7C1S6AH3569JQKAD4C25%2CS78JKH47D23QAC9JQ%2CS459TQHTD67TJC46T%2C%7Crh%7C%7Cah%7CBoard%2011%7Csv%7Co%7Cmb%7C2C%7Cmb%7Cp%7Cmb%7C2D%7Can%7C2D%20bid%20waiting%20--%20forcing%20to%202N%20%7Cmb%7Cp%7Cmb%7C2H%7Cmb%7Cd%7Can%7CTakeout%20double%20--%203%2B%20%21C%3B%203%2B%20%21D%3B%202-%20%21H%3B%203%2B%20%21S%3B%2014%2B%20total%20points%20%7Cmb%7C2S%7Can%7C2-%20%21H%3B%20biddable%20%21S%3B%20forcing%20to%203H%20%7Cmb%7C3C%7Can%7C5%2B%20%21C%3B%207-20%20total%20points%20%7Cmb%7C3H%7Can%7C6%2B%20%21H%3B%2019%2B%20HCP%3B%2023%2B%20total%20points%7Cmb%7Cp%7Cmb%7C4H%7Can%7C2%20%21H%3B%20biddable%20%21S%20%7Cmb%7Cd%7Can%7C5%2B%20%21C%3B%2011-20%20total%20points%20%7Cmb%7Cp%7Cmb%7Cp%7Cmb%7Cp%7Cpc%7CH7%7Cpc%7CHT%7Cpc%7CH2%7Cpc%7CH3%7Cpc%7CSQ%7Cpc%7CS2%7Cpc%7CS6%7Cpc%7CSK%7Cpc%7CS8%7Cpc%7CS4%7Cpc%7CS3%7Cpc%7CSA%7Cpc%7CD4%7Cpc%7CDQ%7Cpc%7CD6%7Cpc%7CD9%7Cpc%7CDA%7Cpc%7CD7%7Cpc%7CD8%7Cpc%7CH5%7Cpc%7CHA%7Cpc%7CH4%7Cpc%7CS5%7Cpc%7CH8%7Cpc%7CHK%7Cpc%7CD2%7Cpc%7CS9%7Cpc%7CC3%7Cpc%7CHQ%7Cpc%7CC9%7Cpc%7CDT%7Cpc%7CC8%7Cpc%7CHJ%7Cpc%7CS7%7Cpc%7CC4%7Cpc%7CC7%7Cpc%7CH9%7Cpc%7CD3%7Cpc%7CC6%7Cpc%7CD5%7Cpc%7CC2%7Cpc%7CCJ%7Cpc%7CCT%7Cpc%7CCK%7Cpc%7CDK%7Cpc%7CH6%7Cpc%7CSJ%7Cpc%7CDJ%7Cpc%7CC5%7Cpc%7CCQ%7Cpc%7CST%7Cpc%7CCA%7C]360|270[/hv]

[Bbradley62]

This is how GIB handles such a hand:

[hv=lin=pn|bbradley62,~~M33937,~~M33935,~~M33936|st%7C%7Cmd%7C4S56KH7D24QAC45JQA%2CSH2368TD358KC3689%2CS2H59JQKD69TJC2TK%2C%7Crh%7C%7Cah%7CBoard%206%7Csv%7Ce%7Cmb%7C4S%7Can%7CPreempt%20--%207%2B%20%21S%3B%2011-%20HCP%3B%203%2B%20total%20points%20%7Cmb%7Cd%7Can%7C2%2B%20%21S%7Cmb%7Cp%7Cmb%7Cp%7Cmb%7Cp%7Cpc%7C]360|270[/hv]