BBO Discussion Forums: I dont think I will ever understand 2/1 - BBO Discussion Forums

Every time I think I am starting to understand 2/1 something like this happens. Ive played bridge for 40+ years and am certainly no beginner but why on earth would North pass the following bid

What on earth am I doing wrong. My bid describes my hand perfectly and is passed by North sitting theer with a void in diamonds and 6 hearts. WTF

When I learned to play bridge the idea was to find a fit, not leave a hand with only 5 trumps. Its ridiulous. Clearly the GiB upgrade today wasnt much use

thepossum, on 2019-February-14, 06:04, said:

You found a fit, clubs, but you did not tell partner.
You also denied 2 hearts, and showed 6+ diamonds.

The best bid with your hand is either 2S (showing the club fit and a max)
or 2NT selling the hand as 10-12 bal, you could also go low with 3C.
Some play 3D in this auction as fit showing, but I dont think GIB is playing that.

I disagree

Bridge is a simple game about describing hands and sharing information and stopping at the best contract

I did not deny a club fit. The best fit was in hearts

Everyone has made the game unnecessarily complicated when a program can't even bid simple sequences

No player in the world would stop with a void like that opposite 5 diamonds when they have six hearts

It's ridiculous

thepossum, on 2019-February-14, 06:45, said:

US Army dont ask dont tell policy seems appropriate.

Who knows what a robot is programmed to do. Try playing with people.

thepossum, on 2019-February-14, 06:45, said:

Once again you ask a question and aggressively disagree with the answer you get. No doubt this response of mine will be presented by you as me being rude too.

No player in the world would bid a non-forcing 2D like that when holding two hearts and four clubs.

thepossum, on 2019-February-14, 06:45, said:

Saying hearts is your best fit is hearts is resulting.
But is also a reason for giving false preference with 2♥

While technically 2♦ can have 5 in practise it is usually 6+
as you would show a heart preference or a club fit (possibly by passing)in 2/1 and in standard

gordontd, on 2019-February-14, 07:44, said:

I agree, but suspect GIB is out of line with the humans in suggesting that 2♦ only requires 5, I can't see what shape it can only have 5 in, since you denied 4 spades, 2 hearts or 4 clubs and BBO doesn't deal 3153s very often. The description is misleading at best.

Maybe worth posting in the robot forum to ask what hand with 5 diamonds you bid 2♦ on.

Cyberyeti, on 2019-February-14, 07:55, said:

It probably doesn't distinguish between the two major suits as opener, and I could just about see a 2D rebid on a five-card suit after partner had opened 1S and rebid a potentially three-card club suit.

I hate to admit it because the bots are just plain nuts but by some accident they have managed to do the right thing for the following (logical not bot) reasons:
1. You KNOW the comp has at least 5h and 3c
2. Your 2d is weak so the first thing your 2/1 partner does (with their minimum) is try to get out of the bidding as safely as plausible AND it assumes YOU are doing the same thing with your 2d bid. So the following happens
3. You did not choose 2h OR pass which would have been very easy safe spots for you to choose rather than 2d
4. Your 2/1 partner decides you chose 2d for one of 2 reasons exceptional length AND/OR solidity of suit. You might choose 2d with a hand like Kxx xx QJT98 xxx KNOWING that even opposite a void your hand will score 3 dia tricks while you may score zero in a heart contract. You might also choose 2d with Qx xx Axxxxxx xx KNOWING your hand might be worth 5 dia tricks but only 1 dia trick in hearts. Note that in both case you hold 2 hearts and meet the described standards provided for a 2d bid.

Your 2/1 partner will not always honor your 2d bid (with a minimum) IF p has a heart suit that might play just as well as your diamonds are suspected to be IF they have a void so you might see a 2h bid with AQxx KQJT9 void xxxx where the computer says well shoot I KNOW my hand is worth 4 heart tricks but might be worth nothing in a dia contract. Unfortunately the heart suit does not meet the requirements for such a pull.

Your hand has some potential and it seems a shame to just pass or bid 2h. I would try the impossible 2s (I see above its supposed to promise a club fit but I have never heard it be that constrained) which I know to mean at least invitational but no clear direction yet OR no spade stop looking for NT. The computer will bid 3c rather than 3n with its highly distributional minimum hand and you can be happy and pass (mp) or give 4c a try (at imps)

gszes, on 2019-February-14, 11:27, said:

FWIW, I was taught that the impossible 2S shows clubs fit and invitational strength (and that's in a system which is conservative about implicit fit in general).

thepossum, on 2019-February-14, 06:04, said:

thepossum, on 2019-February-14, 06:04, said:

This is what you are doing wrong. Based on this thread and many others you have posted, it looks like you are trying to learn 2/1 by looking at what GIB's descriptions of the bids mean.

As you have been told multiple times, this is a silly thing to do. Many of GIB's descriptions, like its description of 2♦, do not accurately convey what the bids mean.

Just because you have a hand which matches the shape and point count described by GIB (which, incidentally, you don't; you don't have 6-9 points) does not mean that it is the correct bid to make. Making a bid shows and denies many more details than can be described by those two pieces of information alone.

After 2♣:

2♦ means: I have a weak hand (under 10 points). Despite knowing your suits are hearts and clubs (albeit clubs may be short), and thus not much room for diamonds, I believe as a partnership, our longest combined trump suit is diamonds.

2♥ means: I have a weak hand. While I may have more clubs than hearts, I believe our longest combined trump suit is hearts.

Pass means: I have a weak hand. Even though you may only have 3 clubs, I believe our longest combined trump suit is clubs. If I had a couple of hearts I would have strained to keep the bidding open with 2♥ in case you have a much better hand, but sadly, I couldn't do so.

GIB cannot represent this information in a description.

Bidding 2♦ makes no sense at all; firstly, you're too strong; secondly, you are completely lying about diamonds being the best trump suit.

First of all, this is not a 2/1 issue except for the fact that 2♣ could be a 3-card suit and therefore raising clubs is not so attractive for you.

There can be two reasons why the robot didn't correct 2♦ to 2♥:
1: 2♥ would, in the GIB system, not be a contract improvement but would be constructive, say 15-16 points with 6+ hearts. I don't know if that is how the system actually works.
2: The simulations shows that pass leads to the best contract in most cases.

2) is not as crazy as it might seem. Your 2♦ bid shows that you have heard that your partner has hearts and clubs but nevertheless you think that 2♦ is likely to be the best contract. By bidding 2♦ you have certainly denied five clubs or three hearts, and four clubs or two hearts are only possible if you have a good six-card diamonds. It is quite possible that passing 2♦ is the best choice, or at least that it is the best choice sufficiently often to make it "win" a limited simulation experiment.

I think your best move after the 2♣ rebid is to bid 2♥. It is a bit hard to see how 2♦ could work better than 2♥. Even if the robot has five poor hearts and three diamonds, your hand is strong enough that 2♥ is likely to make.

If you think that 10 points is too much for a weak bid like 2♦ or 2♥, bid 2♠ which is the "impossible spades" convention. This convention is played by GIB and is quite universal. It shows a good club raise. Opener will now bid 2NT with a balanced minimum. With the actual hand, the robot will probably bid 3♣ although 4♣ or 3♥ wouldn't shock me.

Cyberyeti, on 2019-February-14, 07:55, said:

I think 432-2-AKQT9-5432 would be reasonable. But then again, even if 2♦ shows six and the robot then bids 2♦ on that hand, it wouldn't be the first time the robot (or a human expert) bid the smallest lie.

So I agree with you that 2♦ should be explained as showing six.