[thorvald]

I had this interesting board

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Now the north hand is not easy to bid, but I assume that a majority of players will go for 3N

More interesting is the explanstion of 4♣=4+♠,4+♣, 6+ total points

I have made some simulations and on

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the Bot bids 3N.

So i guess that the right explanation is that 4♣ is 4+♠,4+♣,10+ HCP - unfortunately there is no longer a way to stop in 4N

[smerriman]

The rule written in the database here says that if you have 5+ clubs and enough total points for slam to be at least a possibility, then you can bid 4♣, and this is a higher priority than 3N. With less points and clubs stopped, the next highest priority rule will be to bid 3NT.

But GIB also has a completely unrelated general rule that says if no other rule in the database matches, then a cheapest new suit at the 4 level shows no extra values and nothing more than a biddable suit.

The code takes all possible meanings of 4♣ and outputs the union of the definitions. It just isn't able to determine in this situation, that there isn't a single hand that would result in "no other rule matches".

But this is all really a bit moot here, because GIB is allowed to simulate and pick 3NT instead of 4♣, but determines that keeping slam open will get a better score on average. I don't see that this was the wrong choice.

[thorvald]

I agree that 4♣ could be the right bid, but a terrible explanation, and it would be nice with a definition of 4N as to play, after a new suit at the 4-level in an uncontested auction

[smerriman]

Agree that 4NT shouldn't be Blackwood in clubs. But in most situations, you have to read beyond the descriptions when playing with GIB, as thousands of lines of logic that goes into whether a bid can be made can't be summarised down to a few characters.

[Lovera]

thorvald, on 2022-August-19, 11:25, said:

I had this interesting board

---

Now the north hand is not easy to bid, but I assume that a majority of players will go for 3N

More interesting is the explanstion of 4♣=4+♠,4+♣, 6+ total points

I have made some simulations and on

---

---

---

the Bot bids 3N.

So i guess that the right explanation is that 4♣ is 4+♠,4+♣,10+ HCP - unfortunately there is no longer a way to stop in 4N

It is to note also that are 4 high cards vs 3 of your simulation that can make the difference.