smerriman

I'd just pass 2♥ there. You know partner doesn't have an opening hand (at least by GIB's definition; I expect most would open it), so you have zero interest in game, regardless of whether it's making on this particular freak hand or not. Whatever the description says, 2♥ will almost certainly be a 6 card suit, so it'll be the best place to play.

As Helene said 2♣ as NMF solves this one quite easily, as you immediately find out if partner has 3 spades or not. If not, up to you whether you want to bid 3NT or follow up with clubs if you're worried about diamonds - Kx isn't ideal as dummy so there are arguments either way. (Will depend on what GIB responds to 2♣ too.) There are other hands where NMF doesn't work as well, specifically when you have slam interest, which is why NMF is rarely played at higher levels - better to play 2♦ as artificial and game forcing. But GIB doesn't play that, and here it makes no difference. FSF doesn't exist in this sequence, so you may have misread the descriptions at other tables.

[hv=https://www.bridgebase.com/tools/handviewer.html?nn=Argine&n=SJ9843HQ4D3CQT974&d=w&a=2D(1+!c;%206!d,%20HCP%205-10;%20weak%20hand)P3D(2+!d;%20HCP%20No%20indication;%20fit%20in%20!d)X(4-5!c;%204-5!h;%204-5!s;%20HCP%20No%20indication;%20take-out%20-%20Non-forcing)P]350|200[/hv] What would you bid here? Argine chose..

I've seen GIB actually make a bid showing 15 cards before. But 16 is a new high (albeit not actually bid) :) Pretty tough one for the robot to handle though. It has 3♦ and 3♠ agreeing the minor over 3♣ as specifically programmed sequences, but after 3NT is falling back on generic rules and descriptions, where it simply can't work out there may be implied fit cues available the way it's programmed. So it always loves bidding a new suit 'on the way' after that, and you could have 3 spades after all so it can't eliminate 4NT as Blackwood.. leading to trying to squeeze too many things into too few bids. GIB in South would have bid the same way you did, and it turned out well at least.

This is exactly the type of hand that Gerber is designed for. But it's exceedingly rare, and the vast majority of times lower level players use it, it shouldn't have been used, which is why many people refuse to play it at all. (Or they may have a better use for the bid that comes up more regularly.)

There might be an occasion once every 20 years where preempting, then preempting again, is right. I would rather still not do it even on that occasion just for the partnership's sake.

This sequence is more commonly played as the 'impossible spade', a good raise of the minor, which is pretty useful when it comes up. But the other reasons DavidKok mentioned are pretty important too, since you'll be in trouble when opener has a normal jump shift response. I really dislike weak jump shifts.

Very strange. I don't think it's trying to bid spades naturally. The old version has a rule that says in this situation, if you've ruled out 4♥, then you must cuebid their suit at the 2 level if your total points + the minimum total points partner has shown is at least 25 - ie hands with 12+ total points. The next highest priority rule it looks at says you must cuebid the opponent's suit at the 3 level if you have at least 13 total points. So here it bids 2♠, and it's impossible to reach that second rule since any hand with at least 13 would have matched the first (the latter is designed for situations where the bidding is higher and you can't cue at the 2 level). But if you replace the ♠A with the ♠K, GIB these days passes, while the old version again bids 2♠ (since it still has 12 total points). So I'm guessing BBO added some rules about when you're allowed to pass a penalty double, and then tried to exclude these situations from the 2♠ bid. But this introduced a gap for this hand, where it was excluded from 2♠ but not included for pass, so it falls back to the old 3-level cuebid rule.

Yeah, wasn't necessarily saying that you *should* double, just that is it was another potential option to find clubs, especially if 4♣ is stuck as showing 6. But as to your later point, unfortunately that type of "if then else" isn't remotely possible with the GIB database format. It's pretty insane, which is probably one of the reasons the developers have given up on it. But definitely some fixable parts, if only they'd let someone try :(

For reference, this is a negative double, not a takeout double, which just shows exactly 4 hearts (or possibly 5+ hearts with a hand too weak to bid 2♥). It doesn't say anything about clubs, so it's not accurate to say that it's asking you to "show a second". This isn't entirely accurate either, since you do have the option of doubling to show extras while denying heart support, after which you'll be pretty well placed with any of GIB's responses. But aside from those points, you're obviously right that the description of 4♣ is very silly. While I can replicate it at a bidding table, I can't actually replicate this with the older version of GIB that I have; back then it defined 4♣ as 4+ C; 4+ D; 3- H; 21- HCP; 18-22 total points, and is what GIB picks too. So this must have gotten messed up by one of the changes BBO made since then. However, I suspect the logic is similar to that I posted about in this thread, where GIB has some generic rules about how long a new suit must be if first bid at a certain level, and the fact that diamonds must initially be described as a 3 card suit means its increment function breaks.

I know you prefixed your message to say different people play different things, but this may still be worth going into more detail on as you two don't often disagree: Showing 3 card support with a 3541 type hand seems more logical to me (this was the one pattern not listed in your post - what would you bid with that?), even if it may turn out to be theoretically suboptimal, so is what I would have assumed is standard (and did with my earlier post, though I'll be the first to admit my posts don't ever have much weight behind them compared to yours!)

Fixed. Why a pass changes it into non-Blackwood is bizarre. Equally bizarre is that 4♣ doesn't promise a single club, but is 'to play'.

But North had 15 and rebid 1NT and not 3♥? I guess that's why North thought they had to 'catch up' later. Though having to go to 3♥ with that hand either way opposite potentially no support does feel on the unplayable side.

Yep. With restricted space, 3♥ is pretty wide ranging - game before slam. No, it was natural - mikeh mentioned an artificial convention, but in 'standard' bidding without that or other special conventions, you sometimes need to "lie" by reversing / jump shifting into a 3 card minor, which is what all the other commenters were referring to.

Sure - why not? A jump shift doesn't promise 5 cards in the second suit (in fact can occasionally be even 3, like in your other thread, though that's only when one suited).

North could be 3-5-4-1, simply trying to find a fit.

How would you bid as South with AJxx xx xxx xxxx? 3♥ seems clearcut, so without a fit, 3♠ can't be a cuebid.

Argine doesn't know how to follow up in a checkback auction. [hv=https://www.bridgebase.com/tools/handviewer.html?n=sq987hak63dj74ck6&v=n&a=p1c(4+!c;%20HCP%2011-23;%20natural)p1h(4+!h;%20HCP%204+;%20natural%20-%20Forcing)p1N(4-5!c;%202+!d;%202-3!h;%202-4!s;%20HCP%2015-17;%20balanced)p2c(4+!h;%20HCP%207+;%20relay%20-%20Forcing)p2h(4-5!c;%202-4!d;%203!h;%202-4!s;%20HCP%2015-17;%20exactly%203!h%20-%20Non%20forcing)p2s(4+!h;%204-6!s;%20HCP%207-9;%20natural)&d=e]300|200[/hv] - showing 4-6♠, when it can't have 5-6 or it would have bid 1♠ - showing 7-9 HCP, when it holds 13

This hand isn't worth a 2♠ bid even if you were.

GIB only trots this out with precisely 4450, never 4441.

1♠, then 3♣.

Based on past threads, wbartley only ever plays with basic robots, which don't simulate. Advanced robots simulate, see that passing is insane, and thus never pass. To elaborate on the actual issue, the database basically says to bid 4♥ you need help in spades that this hand doesn't qualify for, and that you should stop in 3♥ with at most 12 HCP. But both of those, as well as 2NT, 3NT, and even 3♠ are marked as permitted bids for advanced robots to choose between. I reported this one myself on the forum ~ 6 years ago and it has come up in other threads since, but when I discovered it was a basic robot problem only, I realised that there isn't really any upside in them fixing it - plugging this type of bidding database gap is one of the main reasons the advanced robot algorithm exists. It's possible that the database gap is even deliberate, since it makes some sense that this is a situation where you would only want to decide by simulation anyway, and basic robots disabling half the algorithm was never really an intended feature of the code.

Mike - it would best if you post the actual hand (and in a new thread, not an old one). I feel like there is a misunderstanding somewhere that hasn't come across in your recollection.

See here for the logic (that was 1NT but it's the same). But this thread has probably gone too far off topic now.

Some people play that 3♣ shows 5-5 in diamonds and hearts (with 2♠ showing hearts + clubs). It appears as if 3♣ is defined to be preemptive in clubs, but the *responses* to 3♣ treat it as the above convention - thus it's preferring hearts over diamonds :(