Why it is hard for robots

[thorvald]

I think this deal illustrates one of the problems with bot bidding, simply the lack of reasoning in the bidding.

 

All need to be defined

 

 

[hv=url=https://www.bridgebase.com/tools/handviewer.html?lin=st||pn|Thorvald,~~M28291,~~M28289,~~M28290|md|2SKJ8HK3DK83CAQJT3,S3HATDAQ9752CK876,SAQT96HQ62DJ64C95,S7542HJ98754DTC42|sv|o|rh||ah|Board%208|mb|1D|an|Minor%20suit%20opening%20--%203+%20!D;%2011-21%20HCP;%2012-22%20total%20points%20|mb|1S|an|One-level%20overcall%20--%205+%20!S;%208-17%20HCP;%209-19%20total%20points%20|mb|P|mb|2D!|an|Good%20support%20in%20S%20--%203+%20!S;%2010+%20total%20points|mb|D|an|11-21%20HCP;%20rebiddable%20!D;%20!DKQ;%2012-22%20total%20points%20|mb|P|mb|P|mb|3N!|an|5-%20!H;%203-5%20!S;%2017-24%20HCP;%20likely%20stop%20in%20!D|mb|P|mb|4S|an|5+%20!S;%208-17%20HCP;%209-19%20total%20points%20|mb|P|mb|P|mb|P|pc|DT|pc|D3|pc|DQ|pc|D4|pc|DA|pc|D6|pc|C4|pc|DK|pc|D7|pc|DJ|pc|S5|pc|D8|pc|H5|pc|H3|pc|HA|pc|H2|pc|S3|pc|S6|pc|S7|pc|S8|pc|SK|pc|C8|pc|SA|pc|S4|pc|SQ|pc|S2|pc|SJ|pc|D2|pc|C9|pc|C2|pc|C3|pc|CK|pc|C6|pc|C5|pc|H4|pc|CT|mc|8|]399|300[/hv]

 

3N can only be a suggestion to play and with a normal 5332 (and even a stopping value in ♦) there is absolutely no reason to bid 4♠

 

My guess is that after showing a 3-card-support we can never stop in 3N (Might be the same reason after 1Ma-3N, where the bot almost always remove to 4Ma)

 

Traveller

 

A direct bid of 3N or bidding 2♣ followed by 3N is the key here, but how can we know 3N is the right contract :-)

[helene_t]

Yes, gib will almost never accept a suggestion to play 3nt after having found a major suit fit. Maybe the explanation of the 3nt bid explains why: 3-5 spades and a likely diamond stopper. So the sims must include many hands that are unsuitable for a 3nt bid

[smerriman]

So the sims must include many hands that are unsuitable for a 3nt bid

I would have agreed.. and as always, any comments I'm making recently are applying to an old version of GIB, so may have changed.. but in this case, not only does my version of GIB bid 4♠ here too, but it's told it's not *allowed* to simulate to choose a different bid. If I turn off that no-simulation flag, it simulates and passes. I think the flag is due to the values it says 3NT promises and the fact it still thinks both players are wide ranging.

 

1M - 3N is different, where GIB passes only if it has exactly 5332 and 12-14 points.