smerriman

Agreed, but if there was no UI at all, and if there was no partnership agreement on 3NT, it's still possible that the only definition of 3NT is "oops, 2NT was wrong", which is the one time you're allowed to wake up. A hand with a control in either or both majors, slam interest or searching for 3NT, would have continued with 3♥ or 3♠, so I don't think that's an option. And can there really exist a hand with stoppers in both majors that wants to bid a natural 3NT?

Is the issue that your partner normally forgets to alert this bid, so when he does alert, you may have some UI from the fact he only remembers to alert when there is something unusual about his hand? That would be a fun one to rule on :unsure:

If they failed to alert, that is UI to you whatever they bid or don't bid diamonds; you bid as if they alerted correctly. If they alerted correctly, you bid as if they alerted correctly; that's not just AI; the fact you're playing the agreed system is information you're *required* to assume.

(Sorry, I was wrong, it does sign off in 4N if you show 0 aces, not that that's possible, so I guess that part is OK) A jack less and it'll bid 3♣ as NMF, or invite with 4N if it didn't have 5 hearts. A couple of points more and it'll ask for kings after 4♠ and then presumably make a decision on grand after that. So generally its logic seems OK here, except for the pointless Gerber ask on this hand, but I guess for a robot, it's probably better to err on the side of gathering more information to help with simulating the final contract than blasting, which unfortunately it doesn't do often enough in suit contracts..

Oh weird, I was sure I had seen in the database that responding 4♣ was disabled, just that it interprets the responses.. but reading again, that's only in response to NT openers. Seems it is told that if it has the points for 6NT in the rare other circumstances where Gerber applies, it should always use Gerber first.. .. and then bid 6NT no matter *what* you respond, even if you show 0. (And yes, all of your descriptions are cut off.)

For reference: 2♥ or 2♠? (Currently 62% 2♥) 3♣ or 3♥? (Currently 60% 3♣ and 30% 3♥ (with 3 votes for 2N)). Not that the majority decision in any poll is necessarily the right one, but definitely a couple of tricky decisions in this hand.

Meta-rule for GIB: every double is for takeout. Meta-rule for Argine: every double is for takeout.. by the opponents.. [hv=https://www.bridgebase.com/tools/handviewer.html?lin=st||pn|smerriman,~~v3fakebot,~~v3fakebot,~~v3fakebot|md|4SK3HQ54DAQ93CQ982,S92H6DT86CAKJ7643,S7654HAJ97DKJ2CT5,SAQJT8HKT832D754C|sv|n|rh||ah|Board%202|mb|1S|an|4+!S;%20HCP%2011-20;%20natural|mb|D!|an|HCP%2011+;%20take-out%20-%20Non%20forcing|mb|1N|an|2+!C;%202+!D;%202+!H;%202-3!S;%20HCP%208-10;%20balanced|mb|D!|an|1+!C;%201+!D;%201+!H;%201+!S;%20HCP%208+;%20penalty|mb|2H|an|4-6!H;%205+!S;%20HCP%2011-16;%20two-suiter|mb|P|mb|2S|an|2+!C;%202+!D;%202-3!H;%202-3!S;%20HCP%208-9;%20preference%20for%20this%20suit%20and%20weak%20hand|mb|P|mb|P|mb|D|an|4+!S;%20HCP%2011-16;%20penalty|mb|3C|an|5!C;%203-4!D;%202-3!H;%202!S;%20HCP%208-9;%20natural|mb|P|mb|3N|an|1-3!C;%201-3!D;%204-5!H;%205-6!S;%20HCP%2011-16;%20game,%20to%20play|mb|D|mb|4C|an|5!C;%203-4!D;%202-3!H;%202!S;%20HCP%208-9;%20natural|mb|P|mb|4N|an|1-2!C;%201-3!D;%204-5!H;%205!S;%20HCP%2011-14;%20minimum|mb|D|mb|5C|an|5!C;%203-4!D;%202-3!H;%202!S;%20HCP%208-9;%20natural|mb|P|mb|5N|an|1-2!C;%201-3!D;%204-5!H;%205!S;%20HCP%2011;%20to%20play|mb|D|mb|6C|an|5!C;%203-4!D;%202-3!H;%202!S;%20HCP%208-9;%20to%20play|mb|P|mb|6N|an|1-2!C;%201-3!D;%204-5!H;%205!S;%20HCP%2011;%20to%20play|mb|D|mb|7C|an|5!C;%203-4!D;%202-3!H;%202!S;%20HCP%208-9;%20to%20play|mb|D|an|1+!C;%201+!D;%201+!H;%201+!S;%20HCP%208+;%20penalty|mb|7N|an|1-2!C;%201-3!D;%204-5!H;%205!S;%20HCP%2011;%20to%20play|mb|D|mb|P|mb|P|mb|P|pc|HA|pc|H2|pc|H5|pc|H6|pc|D2|pc|D4|pc|DA|pc|D8|pc|D3|pc|D6|pc|DJ|pc|D5|pc|DK|pc|D7|pc|D9|pc|DT|pc|S4|pc|ST|pc|SK|pc|S2|pc|DQ|pc|C3|pc|S5|pc|H3|pc|C2|pc|CK|pc|C5|pc|H8|pc|CA|pc|CT|pc|HT|pc|C9|pc|S9|pc|S6|pc|SA|pc|S3|pc|HK|pc|H4|pc|C4|pc|H7|pc|S8|pc|C8|pc|C6|pc|S7|pc|SJ|pc|HQ|pc|C7|pc|H9|pc|SQ|pc|CQ|pc|CJ|pc|HJ|]400|300[/hv]

It's a 19 count, closer to 20, and 3♥ doesn't rule out 3nt, but even if game isn't making with that hand I'd rather be there than a partscore.. and if partner does have a fit a nonforcing bid would often leave us in game rather than a potentially cold slam. Back to the original bidding problem from South's perspective (not North's actual hand), after 1♠ - 2♣ and a likely 2♠, how would people continue? I expect 3♣ given there's no heart fit, but it gets murky after that as to whether we end up somehow bidding 3NT or what to do if not..

Ah, I thought the topic title meant that you thought "4 up 5 down" applied here. Agree it doesn't :)

I don't think you're following the right rules. Just from the perspective of North's first bid, as far as I'm aware the "rule" for takeout doubles is that a 4 card major always takes priority over a minor.

Active forum members are automatically registered. Not many actually play.

Not many people play casual MPs, so it takes a while to build up other tables, and someone has to be the first to play the boards! Just check the scores via the MyHands page later and you'll see them update with a more meaningful number of comparisons.

You've already shown support for diamonds by bidding 2♠, and they were agreed as trumps when partner bid 4♣. Returning to the trump suit in a control bidding sequence doesn't show a control in trumps, just that you have nothing further you want to show at that point.

I don't really see an issue with GIB's bidding here. Give North any non-invitational hand with 4 spades, and they have to bid *something*, so it's impossible to play that 2♠ shows 5 cards. Not just 4333, but a wide variety of hands - you don't want to be making a strong 3♣ bid with 4225, for example. You could make a case for 3♦ showing a minimum with diamond support, but GIB simply prefers keeping the bidding at a lower level. If you have extras, you can bid naturally after that and GIB will correct to spades if they have 5 cards. If you did want GIB to bid 3♦ here, what would you want it to bid with an 11 count and no stopper? You may want to watch Peter Hollands video on support doubles where he covers why rebidding 2♠ doesn't promise anything more than a 4 card suit, and later on he even mentions that 3 of opener's suit is a tricky bid that needs discussion, with some playing it as a minimum (including himself) and some forward-going. (Lastly, even if you did somehow know GIB had 5 spades, you don't really want to be playing at the 3 level with a minimum and an 8 card fit anyway.)

Off-shape doubles are GIB's most well-known issue. Almost sequence starting with such a double is messed up. The description of double is what I was referring to last thread; it's not what it holds / disclosure to the opponents, but the information that partner should assume when making its response. It has a "wipe all information you know so far" flag for rules for some later bids that show a strong hand instead. But these rules are so specific that it often bypasses them, which is why you never double with a one-suited hand playing with GIB (opponents / partner bid in such a way that we're outside the simple followups, and now you're stuck with having showed length in three suits indefinitely). Seems it's not allowed to pass or bid 1NT with this hand, but x followed by 1NT (if the 2♣ bid wasn't made) is 19+ HCP, so that's out too. It's only remaining option is double then immediately cue to wipe-the-info. It was able to do that, but by its next bid we're way past any well defined sequences. 2NT is always accept-if-you-have-slightly-more-than-minimum, and partner has shown 0 points to date, which is where the HCP range comes from. But anything other than 2NT shows an even stronger hand, so it had nothing better.. Playing best-hand tournaments, you get to avoid this more often. Playing with GIB anywhere else, just have to 'wipe-the-info' about the entire hand from your brain and move on :(

Well, whether I'm playing the original or not, it seems you aren't, so I probably need to know what you're playing instead :) Is 2NT GF or inv+? What do other rebids show? If 3♦ is any strength, what are the standard followups?

Yes, leaving before you make your first bid is fine. I believe it also doesn't count against you if someone else leaves mid-hand, and then you leave because the table is no longer complete.

Whenever GIB is simulating what to bid, it assumes all further bids will be made exactly as the non-simulating database predicts (ie what basic robots would do). So it will think that there is a 0% chance its partner raises its bid to 4♠, even though its partner can simulate too and does bid 4♠.

I trust the 3♦ bid so North will be somewhat strong with 5-6 in the minors. 3♠ is clearly a simmed bid that has nothing to do with its description; must be at most 4 HCP for the initial pass, but I wouldn't put it past having just 4 spades, since it knows "book-only partner" will never raise and so it's generally just a forcing bid that's guaranteed to end up playing in a minor. Of course, it's not playing with "book-only partner" and 4♠ is another simmed bid, probably with 2 spades.

Can you post the full hand? 1NT is definitely right as GIB plays 2/1. Double does sound odd but it would be nice to see if something else was going on that you might have missed, as something sounds a little off to me. After 1♠ (P) 1N (2♦) P (P), GIB bids 3♠ every time I try hands that match what you stated. But it's a little hard to tell as you missed a few passes - if you thought 1NT was 6-10 and you passed and it was in fact your LHO who bid 2♦, I can see things going haywire and GIB doubling then, as it isn't really programmed to handle someone passing a forcing bid. (PS - as a complete aside - if you were taught SAYC rather than 2/1, it's still not true that you should support immediately - an immediate 3♠ in that system would show 4 spades. In that case, with an invitational hand, you're meant to bid another suit at the two level, then 3♠ the next round. A 1NT response in SAYC does show 6-10, but doesn't say anything about having a balanced hand - just that you're too weak to bid a suit at the two level).

Close enough :) [hv=https://www.bridgebase.com/tools/handviewer.html?pc=n&s=sa654h965d8ca7653&d=s&v=b&b=7&a=p1dp1sp2dp3dp3nppp&p=h7hth9hqd2d3dad8dkc3d4c4d7s4d9s8dts2d5s5djs9d6s6dqh3c9c5skc8s3sa&e=sjt73hktdak765ct9]400|300[/hv] Partner has AJ8 of hearts and 2 clubs left, so I'll cash the ace of clubs and then return the heart.

Add dummy's hand to the diagram, then append &p=h7hth9hqd2d3dad8dkc3d4c4d7s4d9s8dts2d5s5djs9d6s6dqh3c9c5skc8s3sa , and it will be much easier to follow.

I may have misunderstood since I don't know what you mean by 6.3% incremental probability, but based on those numbers a 3-2 split is 59.6% (plus another 1.4% for West having a stiff J/T), while the same 12 to 7 vacant places numbers gives the club being onside as 63.1%. Ignoring carding / defensive strategy entirely, doesn't this favour the finesse? But nullve makes a good point that West would have thrown hearts with 2 or less, which I think makes a 4-1 heart break even more likely.

You're probably going to be equally unhappy about a 3 card 1♦ opening being passed out - though that's very rare - but undoubled at the 1 level when the opponents probably have the majority of the points isn't even often a bad result. But if anything, I think the opposite logic would apply there - over 1♦ it's exceedingly rare that nobody is going to bid a major; but over a 2 card 1♣ opener it's even more exceedingly rare than nobody can bid 1♦ either, when you only have 3 of them.. and if partner can't, they probably have support.. so it seems a shorter 1♣ is actually safer if that were the concern.