Confused by garbage Stayman-like bidding sequence

[cyrenman]

Playing duplicate IMPs, EW had the following auction:

[hv=pc=n&w=sjt65h7dkq9832cj9&e=s843haq6daj6cat75&d=w&v=n&b=12&a=pp1np2cp2dppp]266|200[/hv]

What would W's next bid have been if E had responded 2♥ to 2♣? Both 2♠ and 2NT would show more values than W had. Would GiB use 3♦ as signoff in the auction 1NT-2♣-2♥-3♦? If it does, the auction makes sense, since if W would rather transfer to 3♦ than pass 1NT, this sequence can look for a 4-4 spade fit along the way, or even play 2♦ instead of 3♦. That seems like an unusual treatment, though, and without it, W would be in trouble after 1NT-2♣-2♥.

 

Any idea what happened here?

[manudude03]

3D would have been forcing. I think West would have bid 2S (yes it shows 9HCP) if there was a 2H response.

[iandayre]

3D would have been forcing. I think West would have bid 2S (yes it shows 9HCP) if there was a 2H response.

 

I agree.

[lycier]

Playing duplicate IMPs, EW had the following auction:

[hv=pc=n&w=sjt65h7dkq9832cj9&e=s843haq6daj6cat75&d=w&v=n&b=12&a=pp1np2cp2dppp]266|200[/hv]

What would W's next bid have been if E had responded 2♥ to 2♣? Both 2♠ and 2NT would show more values than W had. Would GiB use 3♦ as signoff in the auction 1NT-2♣-2♥-3♦? If it does, the auction makes sense, since if W would rather transfer to 3♦ than pass 1NT, this sequence can look for a 4-4 spade fit along the way, or even play 2♦ instead of 3♦. That seems like an unusual treatment, though, and without it, W would be in trouble after 1NT-2♣-2♥.

 

Any idea what happened here?

 

Hi, welcome to Gib forum.

Even you can't afford your original hand, I can make a similar hand to show its issue.

Hand-1

[hv=http://www.bridgebase.com/tools/handviewer.html?sn=Robot&s=SAQ2HJ953D754CQ62&wn=Robot&w=SJT65H7DKQ9832CJ9&nn=Robot&n=SK97HKT842DTCK843&en=Robot&e=S843HAQ6DAJ6CAT75&d=w&v=o&b=8&a=PP1N(notrump%20opener.%20Could%20have%205M.%20--%202-5%20%21C%3B%202-5%20%21D%3B%202-5%20%21H%3B%202-5%20%21S%3B%2015-17%20HCP%3B%2018-%20total%20points)P2C(Stayman%20--%2011-%20HCP%3B%2012-%20total%20points)P2D(No%20major%20suits%20--%202-5%20%21C%3B%202-5%20%21D%3B%202-3%20%21H%3B%202-3%20%21S%3B%2015-17%20HCP%3B%2018-%20total%20points)PPP&p=D4DKDTD6DQH2DJD7H7H4HQH5DAD5D8C4S4S2SJSKS7S8SAS5SQS6S9S3C2C9C3CTH6H9D9HTD3C8C7C6D2H8C5HJSTCKHAH3CJHKCACQ]400|300[/hv]

 

Here we can't see its reason,so I would better make another similr hand.

Hand-2

[hv=http://www.bridgebase.com/tools/handviewer.html?sn=Robot&s=SAQ2HJ953D754CQ62&wn=Robot&w=SJT65H7DKQ9832CJ9&nn=Robot&n=SK973HKT84DTCK843&en=Robot&e=S84HAQ62DAJ6CAT75&d=w&v=o&b=8&a=PP1N(notrump%20opener.%20Could%20have%205M.%20--%202-5%20%21C%3B%202-5%20%21D%3B%202-5%20%21H%3B%202-5%20%21S%3B%2015-17%20HCP%3B%2018-%20total%20points)P2C(Stayman%20--%2011-%20HCP%3B%2012-%20total%20points)P2H(2-5%20%21C%3B%202-5%20%21D%3B%204-5%20%21H%3B%202-4%20%21S%3B%2015-17%20HCP%3B%2018-%20total%20points)P2N(Invite%20to%203NT%2C%20no%204-card%20major%20--%209%20HCP)PPP&p=H3H7HTHQDJD4D2DTS4SQS5S9HJS6H4HACAC2C9C4DAD7D3C3D6D5DKS7DQS3C7S2D9C8CTH9D8HKH6H5CJCKC5CQH8H2C6STSKS8SASJ]400|300[/hv]

 

First issue

Surprisedly, Gib W rebids 2nt and denies any 4-card major for invitation after opener's 2♥.

 

Second issue

So we can see that Gib W might take its 9TPs as 9HCP for invitaion. And it should show Gib evaluation count is just in confusion.

 

 

You said " What would W's next bid have been if E had responded 2♥ to 2♣? Both 2♠ and 2NT would show more values than W had. Would GiB use 3♦ as signoff in the auction 1NT-2♣-2♥-3♦? If it does, the auction makes sense, since if W would rather transfer to 3♦ than pass 1NT, this sequence can look for a 4-4 spade fit along the way, or even play 2♦ instead of 3♦. That seems like an unusual treatment, though, and without it, W would be in trouble after 1NT-2♣-2♥. "

 

I think the best bidding sequences are

 

[hv=pc=n&w=sjt65h7dkq9832cj9&d=w&v=0&b=8&a=pp1np2cp2hp2sp2np3dppp]133|200[/hv]

 

However Gibs have no ability to understand my bidding sequences at present.

[cyrenman]

Surprisedly, Gib W rebids 2nt and denies any 4-card major for invitation after opener's 2♥.

That is quite surprising, thank you very much for testing this sequence!

 

I think the best bidding sequences are

 

[hv=pc=n&w=sjt65h7dkq9832cj9&d=w&v=0&b=8&a=pp1np2cp2hp2sp2np3dppp]133|200[/hv]

I agree that is best, assuming one is willing to give up 2♠ as either natural with invitational values or a heart raise.

[Stephen Tu]

I think 2♣ is fine, personally, planning on 2♠ if that's systemic. Yes it's only 7 HCP, but KQxxxx is worth an upgrade. There's just a ton of game potential if partner fits spades, that passing 1nt gives up on. Yes, 2nt rates to fair poorly if you catch partner with xx/Jx in diamonds only. But with Ax in diamonds you are providing 5 tricks a lot of the time, and the black suit jacks will often contribute to a 6th.

 

After all, look at the example hands posted, with partner having A of diamonds and some aces outside, I'd actually really like to be in 3nt in all of them. So I support GIB not passing.

 

It would be nice to be able to follow up with 3d over 1nt-2c-2h-2s-2n, but that's probably not defined well currently.

[Stefan_O]

What would W's next bid have been if E had responded 2♥ to 2♣?

 

Gib tends to Pass, when it suddenly cannot find a matching continuation in its database-rules.

It never stops to asks "what should I bid next round?"

I'd not be very surprised if it would Pass and play in 2H.

 

There have been many examples of such disasters, posted on this forum.

[iandayre]

Gib tends to Pass, when it suddenly cannot find a matching continuation in its database-rules.

It never stops to asks "what should I bid next round?"

I'd not be very surprised if it would Pass and play in 2H.

 

There have been many examples of such disasters, posted on this forum.

 

You may be right Stefan, but I'll give GIB the benefit of the doubt and assume an advanced GIB would continue with 2S. Stephen is right that this specific hand could offer a good play for 3NT, but GIB can only count points, can't distinguish between this hand and one with the same shape with the top honors in S instead.

 

All this points I think to closely defining 1NT-2C-2H-2S-2NT-3m as natural,non-forcing.

[Stefan_O]

... but GIB can only count points, can't distinguish between this hand and one with the same shape with the top honors in S instead.

 

Ummm... but it can run simulations...

That might compensate for some of its walrus-counting habits, I would think...?

[jdonn]

It seems to me GIB bid this hand rather well. This is hardly anything I am inclined to suggest BBO spend resources working on.

[Stefan_O]

True.

All well, that ends well ! B-)