6+3 Major or 4+4 minor

[Bbradley62]

[hv=sn=bbradley62&s=SKQ7HKDKT84CAKQJ2&wn=Robot&w=S84HQT6432D632C53&nn=Robot&n=SAJT632H7DAQJ9C94&en=Robot&e=S95HAJ985D75CT876&d=s&v=b&b=7&a=1C(Minor%20suit%20opening%20--%203+%20%21C%3B%2011-21%20HCP%3B)P1S(One%20over%20one%20--%204+%20%21S%3B%206+%20total%20points)P2D(Opener%20reverse%20--%205+%20%21C%3B%204+%20%21D%3B%203-%20%21S%3B%202)P3D(4+%20%21D%3B%208+%20HCP%3B%20forcing%20to%203N)P3S(5+%20%21C%3B%204+%20%21D%3B%203%20%21S%3B%2021-%20HCP%3B%2018-22%20total)P4N(Blackwood%20%5BD%5D%20--%204+%20%21D%3B%2015+%20total%20points)P5H(Two%20or%20five%20key%20cards%3B%20no%20queen%20--%205+%20%21C)P6D(4+%20%21D%3B%2015+%20total%20points)PPP]360|270[/hv]Why does North choose diamonds over spades?

[Antrax]

Looks like the old issue where once a suit is agreed it's trumps forever. The fact 4NT is keycard for ♦ is a strong indication for that, when there's no suit agreement GIB plays 4NT as keycard for the last naturally-bid suit.

That being said, isn't it better to play in your 4-4 fit?

[1eyedjack]

6S is a slightly better contract because you are slightly less likely to sustain a D ruff before drawing trumps in 6S than to sustain a S ruff in 6D. There seems to be no other difference here. Also of course it scores better, which is a huge plus if MP (not stated either way).

[Bbradley62]

That being said, isn't it better to play in your 4-4 fit?

With my first three bids, I've shown at least 5 clubs, exactly (despite the description) 4 diamonds and exactly 3 spades. If my 13th card is a 6th club, North should expect to be able to ruff a heart in the short hand playing spades, which makes that better than playing in diamonds. I think it would be very difficult, looking at the North hand, to construct a South hand meeting the bidding criteria that makes 6♦ a better contract than 6♠.

 

PS: If the 3♦ bid is going to irrevocably set diamonds as trump, 3♠ should be a cue bid, not a length-showing bid.

 

PPS: Why does spade length disappear from the descriptions of North's bids, starting with 3♦?

 

PPPS: I suppose that if 3♦ shows 4+ diamonds and more spades than diamonds (given GIB's up-the-line style), I should just bid 4N over 3♦ and get the contract to 6♠. Or would GIB overrule me and bid 7♦?

[georgi]

Nice case.

 

Regarding 3♦ missing spades ( or responder first suit). It's fixed in v30 ( current one ). There was a bug which masked previously promised responder's suit. Now shows 4+ 4+ again.

 

 

Regarding blackwood.

 

Easy solution could be GIB just to stop in spades in case there are 8+ cards ( GIB will need to look in hand at that moment ).

 

If blackwood is generally over spades might be risky as responder could have just 4 spades and while opener promised just 3 ( overall 7 cards to this moment ) to be undesired contract.

 

So a probable improvement could be regardless the way of bidding( not only after reverse ). GIB might be improved to pick a contract after 4NT where there is higher ranked suit ( mostly major vs minor ).

 

Since two versions ago ( v29 and v30) partner GIB would pass such slam where there are 6+ shown cards ( could be only by opener/responder or also by both partners ).

[Bbradley62]

Several "coulds" and "mights" in that response. Does that mean you're thinking about what to do to fix this?

[georgi]

I would address this for design decision. Then a change would be applied or kept as it is :)