Two problem found in recent challenges

[cvcherry]

I play friend challenges a lot, and recently I found two deals where GIB wasn't understandable.

 

The first one is in bidding. It's probably not really a bug, but it seems GIB's hand evaluation isn't well-defined.

 

My table:

[hv=pc=n&s=s7652h9dt93caq754&w=sqj3hkqj87dk876c6&n=sakt98hat632dackj&e=s4h54dqj542ct9832&d=n&v=0&b=1&a=1sp2sp4dp4np5dp5hdrp6sppp]399|300[/hv]

Maybe my bid wasn't perfect, but at least it's a good slam. BTW, I should mention a minor problem here. 5♥ is asking queen and doubled, then what's North's redouble mean? I think it should be DOPI, showing no queen. But GIB says it showing ♥A which I think it's not very reasonable. (This hand has no queen just by accident)

 

However, which I mainly want to show is my opponent's table. When the challenge finished I saw my opponent stopped in 4♠, but when I saw what happened, I was shocked.

[hv=pc=n&s=s7652h9dt93caq754&w=sqj3hkqj87dk876c6&n=sakt98hat632dackj&e=s4h54dqj542ct9832&d=n&v=0&b=1&a=1sp3sp4sppp]399|300[/hv]

 

We know, 3♠ is limit raise and should be stronger than 2♠. How can North have some slam interest after 2♠, but no interest after 3♠???

 

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Now the second hand. It's a very silly defensive error I think.

[hv=pc=n&s=s942hak85da76c954&w=sa875hj32d4cak732&n=sqj3h97dqjt853cj8&e=skt6hqt64dk92cqt6&d=w&v=0&b=8&a=1c2dd3d3sp3nppp&p=d7d4dtd2dqdkdac2d6s5d5]399|300[/hv]

The third trick totally shocked me. East shown stopper, so I can't lead ♦A and instead choose ♦7. North surely should know ♦ are all good, but how can North didn't take third trick and save the contract from down 4 to made? Can North think I was dealt ♦9? But if so, I should play it earlier to avoid blocking. This is totally undesirable for us.

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Looking forward for explanation and maybe further repairs. I created diagram here because I forgot how to post link directly, but they are absolutely true deals, I swear.

[hrothgar]

Few comments about the first hand:

 

1. Responder's hand is arguably not suitable for a single raise to begin with

2. With this said and done, it revalue enormously opposite the 4♦ splinter. Nothing is wasted in Diamonds, a ruffing value, the club suit looks golden, and an extra trump. Opener has said that they are interested in exploring slam opposite a single raise. Could responder possibly hold anything better?

3. As for North, North has more bidding space available opposite the single raise and is choosing to take advantage of this

4. Its weird that an identical start to the auction leads to a different choice of bids? (Are you using the basic robots? If so, be aware that they are even wonkier than the normal ones)

[HardVector]

On the second hand, I think the bot thought you had A976. If they take the 3rd trick, the suit is blocked. I'm curious as to why you led the 7 from A76? I'd be interested in finding out if you had led the 6 if the bot would have gotten it right.

[StanR]

On the second hand, I think the bot thought you had A976. If they take the 3rd trick, the suit is blocked. I'm curious as to why you led the 7 from A76? I'd be interested in finding out if you had led the 6 if the bot would have gotten it right.

GIB may not think this way, but it wouldn't make any sense for East to duck the first trick holding only K2.

[HardVector]

GIB may not think this way, but it wouldn't make any sense for East to duck the first trick holding only K2.

I'm just trying to find some rationale for not taking the 3rd trick. A976 is the only thing.

[cvcherry]

On the second hand, I think the bot thought you had A976. If they take the 3rd trick, the suit is blocked. I'm curious as to why you led the 7 from A76? I'd be interested in finding out if you had led the 6 if the bot would have gotten it right.

If I hold A976, I would lead 6 (4th). And also if I had already led 7 by mistake, I must had unblocked 9 to second trick.

Sorry my opponent didn't lead diamond, I don't know what will happen if lead 6. But I don't think 6 is proper lead here (might confuse partner, did I have 4 diamonds?)

[cvcherry]

Few comments about the first hand:

 

1. Responder's hand is arguably not suitable for a single raise to begin with

2. With this said and done, it revalue enormously opposite the 4♦ splinter. Nothing is wasted in Diamonds, a ruffing value, the club suit looks golden, and an extra trump. Opener has said that they are interested in exploring slam opposite a single raise. Could responder possibly hold anything better?

3. As for North, North has more bidding space available opposite the single raise and is choosing to take advantage of this

4. Its weird that an identical start to the auction leads to a different choice of bids? (Are you using the basic robots? If so, be aware that they are even wonkier than the normal ones)

 

It's friend challenge, so we were South, I bid 2♠ and my opponent chose 3♠.

Sorry I don't know how to add names in hand diagram, and maybe it confused you.

You are right so I did blackwood.

When we play friend challenge we don't check the advanced robot option.

 

But if robot opener had slam interest after 2♠, how can it had no interest after 3♠. 3♠ was surely stronger. It's true North had fewer choices, but I think either cuebid or blackwood is OK.