xxhong

Why 1S then 2H would show only 5 spades? There must be some bugs in the rules. Actually there are quite a few such kind of situations when gib bids two suiters. I saw gib rebids a suit and bypass a 5 card side suit sometimes.

So what is the definition of signaling situations in gib's code?

There is one problem for this sequence. 2S is just one round forcing and 3C is nonforcing. I think opener's strength is stronger than a nonforcing 3C. So 3D can be a better bid here IMO. 3H is also a choice. However, now you have a problem to ERKC because 5D over 3H can easily be an ERKC for H. One key issue for this hand is that 3D showing long C and gf hands works better than a 3H reverse when partner holds a D void.... That's something I never thought of before. Also, 3D would allow you to find 4-4 H fit anyway.

Now the explanation for 5H is 12+ total points and 5+ H. This simply can't be correct. The correct meaning of 5H should show a strong H suit and offensive oriented hands. For example, 5H should show something like x KQJTxx AKxx xx. Not something like Qx AKxxx Kxx xxx, which is a clear pass over 4S x.

2/1 makes slams and game bidding rather simple. Typical sequence in 2/1 gf is to find a trump fit at 2 or 3 level, then cuebid for slams. non 2/1 systems frequently need good guesses in sequences like: 1S 2H 4H ?

The explanation of 5H is clearly wrong. A rebid at 5 level should show a strong suit.

I think the key issue is to play the double as seeking for a stopper in D instead of negative doubles. A pure negative double here is difficult to play.

I think the bot should always trust opp's bots' bidding, but not trust human opp's bidding too much. At least, it should set a wider range for opps' bidding. For example, a human opp may open 1NT with 12-18 HCPs, with singletons or 6 or even 7 card suits. In a more sophisticated practice, it should certainly build a database on human opp's bidding history and determines how likely opps's bidding deviates from the system. That's certainly an enormous task. I think those poker bots do have methods of historic play of opps implemented.

It appears that attitude is often more critical in many situations?

I think it can be applicable to many other situations too. Counting for slams is the first step. For example, a sound 2C opening scheme should also involve total trick counts if the HCP is less than 20. Also, for any high level competitive decisions, gib should have total trick counts as well. Now the scheme is very wrong. Generally, when gib thinks its side is likely to make a game, it would double no matter which hand type it holds. It can be based on a lot of tricks and offensive oriented hands, it can also be based on quite defensive oriented hands. The total trick count would offer a pretty good guideline to decide to bid or to double. Also, for penalty double decisions, trick count is especially useful. Suppose you hold xxx xx AKQJxx Ax, you have only 14 HCPs, but 7 tricks, so you actually should double 1NT openings. This is also very true for high level penalty doubles. For example, if you hold SAKQJ and opps bid 4S after a 2/1 constructive sequence with 4-4 fit, you should double this 4S to take your sure money. Only when trick count is implemented can you really implement good penalty doubles at high level. Now gib simply misses many such kind of chances. The number of total tricks you can take is a very important parameter in bridge bidding. Without this parameter, the bidding can be very difficult, and a lot of nonsense sequence would occur. If every bridge player would consider the total trick taken in every hand, there is just no point not to allow bridge program to have this ability IMO.

I think 1C contains a lot more balanced minimum hands than 1D.

Simulation is not a sure thing. It's a matter of luck, especially when the sample size is only 10-20 hands (Also, gib program has bugs to simulate when it holds a strong hand, it often generates wrong results, that's why gib rarely bid correctly after 5NT king asking). Trick counting is way much simpler and really it should be applied. For this example hand, a trick counting method would just say that this hand is likely to produce 13 tricks, so a 7S should be bid. Also, the basic philosophy of trick counting is way more solid than simulations. Now the simulation is based on the bidding history. If the opp intends to provide the wrong bidding, simulations would usually fail. Trick taking is always sound no matter what opps bid. This is extremely important in human-gib vs. human-gib money games. This is really not very difficult to implement a trick counting method, especially for suits like AKQJxx. All you need is a simple table of honor combination, suit length and their corresponding tricks. I think this simple evaluation would improve gib's bidding a lot.

For now, I think a good fix is to set 1C 1S 2D 4C as a good hand with C support which has some slam interest. Also, 4D shows a good hand with D support. a typical range should be 11+, not some random 7+ total points. This is a very simple fix. Also, now the 1C 1S 2D 3C isn't very playable. 3C as I remember shows 6+. IMO, it should show 6-7 and is passable. With better hands, you either bid 4C to show slam interest, bid 5C to play there, bid 3NT when you think you have a reasonable chance to make it, or bid the 4th suit when you don't have a stopper. Also, 2H to be natural doesn't make much sense here because opener has denied 4 hearts. It can be useful only with 5-5 majors, still, that's rare and you can always bid 2H then later 3H to show that shape. There are indeed many such kind of bad designs in the system. A simple system doesn't mean it has to be bad. Just like the well known case of 1H 1S 3H, it really can't show 16+. It should be something like 16-18, with 19+, a simple system would just bid 4H or 3NT, depending on the H length and quality.

With 5-5 minors, shortness in H, partner can usually pull this penalty double to show his shape. So gib shouldn't really make the final decision on the assumption that partner would pass the double with 5-5 and weak hands. So it's likely a system flaw.

This is still a evaluation problem. Gib has no method to count total tricks, which is being done by human in every hand. For example, with AKQJxx, you should count it for 6 tricks in most situations. AKQ is 3 tricks. A is one trick. Kx is half trick, QJT is one trick. AQ is 1.5 trick. This kind of counting would allow gib to make sensible decisions when holding very strong hands or making slam decisions. This is also why gib is so bad after 5NT King asking, because gib only relies on simulations, but not on trick taking. For grand slams, the basic rule for human to bid 7 is when you can count 13 tricks (or you are likely to get 13 tricks).

Yes, there missed some important logic links in gib bidding. For example, if 5H invites 6H, 7H shouldn't be bid. Also, 6NT is not an invitation to bid 7H. I think the fix is really easy, "if partner's bid is 6NT, my bid is pass".

This is a 4H bid. This hand is way more stronger than xx KQJxxx xxx xx.

Playing traditional acol, I think south's hand is a 2NT bid, which is natural and nonforcing. 2D then later raise should show distributional hands. Of course, nowadays, most play 2NT as J2nt I think, in that sense, perhaps 1NT response is fine if you play a 14-16 1NT opening.

Perhaps you can post the link to access recent money bridge activities that has the hand record and requires the input of my password. I can use my web browser to find the hand. I now don't have access to both webclient and windows client because the port is blocked.

No, it's bbo web robot! It's played against another human for money. Also, it's not inverted minor. The bidding is: 1D 1H 1N 2C 2D 3C

What you should worry more is the explanation of 4C to show 1C+, which is just a huge nonsense.

Yes. Otherwise, I'd say it's money bridge tournaments.

This distribution is a little bit unlucky. I play good bad 2NT here. So good offensive hands bid 2NT and weak offensive hands bid 3C. I'll probably just bid 3C here to show an offensive hand in the weak range. After that, responder should still move on to bid 3S probably. Then the opener would bid 4C to show 7 or very good 6, which can be passed or raised by partner and later get doubled.

I think south made three mistakes. The first one is 2C, this hand is way too strong for a 2C overcall, you need very little from partner to have a play 4H, like Hxxxxxx is often enough. Double is a clear cut IMO. The second is the double. 7-4 distribution strongly suggests to play usually. 4NT is clear to show 6C and 4+ side suit. 6C is also rather bad, partner may hold CQxxx and nothing else in this auction. Still, 6C is not a bad contract.

All the money bridge hands are not in my_hands. And I am just posting it as what it means, not what exactly shows on the screen. This is definitely a bug and should be easy to reproduce.