[Yu18772]

http://tinyurl.com/7lh3eqw
Is supporting with 3 cards now a standard for GIB or glitch (especially given a legitimate alternative) ?

[aguahombre]

looks like a good contract to me.

[Yu18772]

not the point. If Gib supports with 3 cards regularly that what its explanation should say. On this particular hand I would hope we would still get there

[Yu18772]

deleted double-posting

[P_Marlowe]

Yu18772, on 2012-January-03, 02:18, said:

not the point. If Gib supports with 3 cards regularly that what its explanation should say. On this particular hand I would hope we would still get there

But this is the point.

GIB uses simulation to support its bidding decision, something good players do as well,
they dont call it simulation, they call it whatever, one common technique is to construct
one or two minimal hands, to see, if certain contracts have a reasonable chance.

As it is, raising with 3 card support and a 5431 shape with at most 15HCP is quite good.

And if you calim ... you hope to get to 4S anyway, feel free to post a auction, that GIB
understands.
As it is, if GIB bids 2C, the only alternative to 2S, than the only sensible 2nd bid by
responder is 3NT, followwed by all pass.

With kind regards
Marlowe

[Bbradley62]

P_Marlowe, on 2012-January-03, 05:54, said:

And if you calim ... you hope to get to 4S anyway, feel free to post a auction, that GIB
understands.

1♦-1♠
2♣-2♥!
2♠-4♠ choosing to play in a Moysian knowing that pard is short in ♥

[barmar]

This is actually an explicit bidding rule. With 3 card support and at least KJx in the suit, we'll raise if our shape is 5413, unless the 4-card suit is spades.

It's intentionally not included in the explanation. Just as with human players, you generally assume that the raise shows 4 card support, with the understanding that sometimes they lie.

[Yu18772]

P_Marlowe, on 2012-January-03, 05:54, said:

And if you calim ... you hope to get to 4S anyway, feel free to post a auction, that GIB
understands.
As it is, if GIB bids 2C, the only alternative to 2S, than the only sensible 2nd bid by
responder is 3NT, followwed by all pass.

The most direct option, that would probably happen at the table is what Bradley62 kindly posted.
Another option :
1♦-1♠
2♣-2♥!*
2♠-2NT
3♥**-4♠..........
**I hope that it shows singleton now with GIB - dont know.
or
1♦-1♠
2♣-2♥!*
2♠-3♦
whatever denies♥stop-4♠..........

and there at least a couple of others I could do with a good human partner that will end in 4♠ and not 3NT. I dont think GIB bids support here because that fits the drawbacks of its bidding over 4th suit forcing.

barmar, on 2012-January-03, 16:36, said:

This is actually an explicit bidding rule. With 3 card support and at least KJx in the suit, we'll raise if our shape is 5413, unless the 4-card suit is spades.
It's intentionally not included in the explanation. Just as with human players, you generally assume that the raise shows 4 card support, with the understanding that sometimes they lie.

Barmar - your explanation is a bit self-contradictory - either this is an explicit rule in a partnership, then it should be stated to the partner, or GIB considers this bid a necessary lie - than it has a truthful alternative, and the bid should be fixed. Good human partners are expected to lie only if there is not truth available, or the truth is most likely to cause a bigger lie in the near bidding future, otherwise they expect a partner to consider it as one of possible hands.

Just to make it clear - OP is not a criticism of the bid, as of the explanation given by GIB - this support style is ok; although not to my taste, many players that I consider much better and smarter than me advocate it. However, as an explicit style of bidding it has implications on many constructive as well as competitive auctions. Support with 3 on HHX is very common in US, but not necessarily in other parts of the world. A lot play that support is 4 cards unless no other bid is available (which makes it negligibly rare, and partner indeed assumes 4). If this support bid is made on any HHX with 3154 than it becomes a viable option and requires slower and more cautious bidding on other hands.
Also, regardless of this specific issue - imo anything that is an explicit style by GIB is something his partner deserves to know, just as one would if they could have a prior to game discussion with any new human partner.

[barmar]

There are over a thousand bidding rules where there's either no associated explanation (that's the case with the 3-card raise, so you get the explanation from other bidding rules) or the explanation doesn't precisely match the criteria for the bid (sometimes they differ by a point). Most of these lies are intentional.

In this case, we've decided to treat a good 3-card suit as if it's 4-card support when we have a side singleton. When you sit down with a pick-up partner, how often do you discuss this stylistic issue? I've played with many pick-ups (and I'm not talking about online, where you often have no discussion at all, but f2f at clubs and tournaments, spending 10-15 minutes filling out a convention card), and this almost never comes up.

This is just bridge judgement, perhaps with some regional biases. I've heard that French players would never consider a 3-card raise, but it's fairly common among US players. But if you asked their partner, they'd probably say that they expect 4 cards, or they might qualify it with "usually".

[Yu18772]

I dont discuss it with pick up partner on bbo -but the first time he does it I ask him not to do it again. The second time he does it he stops being my partner. With GIB I dont have the luxury of asking anything, discussing anything, or have any say at all. So I at least deserve the courtesy of having as full description of GIBs preferences - the same info my GIB opponents have?
In real life, since I much prefer European style and I am aware that it is common to support on 3 card in US I ALWAYS discuss it with a partner. Just like I discuss skipping diamonds, style of preempts and openings in 3rd seat, potential responses to reverse sequences and other things that may or may not be on convention card. I dont see the benefit of intentionally hiding info from humans about GIBs preferences - with all due respect most problems with GIBs rise from misunderstandings, so I dont get the idea behind making it worse partner than it actually is by augmenting them.

[Bbradley62]

barmar, on 2012-January-05, 14:42, said:

When you sit down with a pick-up partner, how often do you discuss this stylistic issue?

Maybe this post reveals something about an underlying attitude. For many BBOers, (including those who play ACBL-sanctioned Robot games) GIB is not a pickup partner; GIB is their most regular partner. Such players would like system notes and explanations consistent with an established partnership, not consistent with a pick-up partnership.

[cloa513]

Bbradley62, on 2012-January-06, 09:51, said:

Maybe this post reveals something about an underlying attitude. For many BBOers, (including those who play ACBL-sanctioned Robot games) GIB is not a pickup partner; GIB is their most regular partner. Such players would like system notes and explanations consistent with an established partnership, not consistent with a pick-up partnership.

And they pay for the access. Playing sponsors expect more in real life.

[Yu18772]

I dont think its about paying or at least for me its not. I play with GIB for several reasons, but the main one is my own curiosity - how good a computer program is or can be? Not being a complete stranger to computers or statistics I can more or less imagine, and I do think that ultimately a computer will be able to make a good player or even a great one. That being said - for computer to become a good partner someone needs to develop it as such - and at this point it seems that the GIB team is not aiming there.
My understanding of barmars post is that he seems to think that GIB experience should mimic as closely as possible the worst of real bridge experiences - a pick up random partnership......too bad, I actually thought this forum was about improving GIB not making excuses.

[barmar]

We're trying to make it like "normal" bridge.

Where we play, this auction is generally presumed to show 4-card support. However, we all realize that sometimes partner needs to bid it with only 3, because all other bids seem worse: rebidding a 5-card suit, bidding NT with a singleton or small doubleton, or reversing without a strong enough hand.

If I were responder, and asked to explain opener's raise, I would say "I expect 4 cards, but it's possible he could have 3 in some cases." In most cases I would continue bidding on the assumption that he has 4, but occasionally I may be able to cater to the possibility of 3. For instance, if I have concentrated values in the unbid suits, I can bid 2N or 3N to let him know that I can cover his possible shortness there, and give him the choice of strains. But most of the time, you just trust that if partner had a reason to treat his 3 cards as 4, there's a good reason.

This is considered normally bidding logic in the US, and it's how we've programmed GIB. If we described the raise as only showing 3 cards, it would make it much harder for GIB to find proper followons. Just as human players do, we want it to bid as if partner probably has 4. Unfortunately, GIB doesn't have the notion of "probably" -- the bid either promises 3 cards or 4 cards, we can't say "75% probability of 4". It also doesn't know about "OR" -- we can't say "promises 4 cards OR 3 cards with side shortness", so that GIB can make an informed choice of whether to play in the Moysian.

And we also don't have a way of giving different explanations to the user than it uses internally for deciding its followon bids.

So we've gone with having the bid promise 4, with the understanding that sometimes it's a lie. GIB makes 3-card raises in situations where the Moysian is likely to be reasonable.

[Bbradley62]

barmar, on 2012-January-09, 14:03, said:

So we've gone with having the bid promise 4, with the understanding that sometimes it's a lie. GIB makes 3-card raises in situations where the Moysian is likely to be reasonable.

Another wonderful concise explanation that could be included in system notes

[barmar]

It's already in there, under Responses and Rebids: "Raising responder's suit usually promises 4 cards, but will occasionally raise with only 3"

[Jyrki_63]

Well. I once raised GIBs 1H response to my 1m opening with Kxx and a goodish 14 TP. When I later offered 3NT as an alternative (a human would take that as "choice of games", i.e. expressing doubt about hearts, GIB put itself to 4H with a trump suit of 6542!

It is not catering for its partner to do this with only 3 ;-)

[barmar]

Jyrki_63, on 2012-January-15, 14:15, said:

Well. I once raised GIBs 1H response to my 1m opening with Kxx and a goodish 14 TP. When I later offered 3NT as an alternative (a human would take that as "choice of games", i.e. expressing doubt about hearts, GIB put itself to 4H with a trump suit of 6542!

It is not catering for its partner to do this with only 3 ;-)

That's because the raise "shows" 4. You're only supposed to do it with a hand where the 3 card support plays like 4, because your hand is inappropriate for NT (due to side shortness). You can't change your mind and offer NT later.

It's the original bidder of the suit who's allowed to make this offer, not the raiser. I don't think GIB will ever do so, though -- he believes your raise shows 4.