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oddities of gib

#1 User is offline   cencio 

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Posted 2020-January-07, 14:50

After putting gib robots on all seats.
Gib doesn't play the same hand in the same way.
May this happen also in tournament?
https://www.youtube....h?v=Yofo8GeXX7c
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#2 User is offline   pilowsky 

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Posted 2020-January-08, 01:41

Neither do people.
Fortuna Fortis Felix
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#3 User is offline   hrothgar 

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Posted 2020-January-08, 01:48

BBO's Basic Robots will deviate in their bidding / play

BBO's Advanced Robots will behave identically IF everything before hand has been the same. This includes bidding, the play of small cards, etc.
Alderaan delenda est
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#4 User is offline   barmar 

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Posted 2020-January-08, 09:06

View Postcencio, on 2020-January-07, 14:50, said:

After putting gib robots on all seats.
Gib doesn't play the same hand in the same way.
May this happen also in tournament?
https://www.youtube....h?v=Yofo8GeXX7c

That video is using the old, download version of BBO. That version runs non-tourney robots on the user's PC, not on our servers. It's a very old version of GIB, its play is dependent on the speed of the user's computer, and it also doesn't use the same random number generator at all tables.

You can't compare it with the online version of GIB that's used with the web versions and in tourneys.

#5 User is offline   funnyman 

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Posted 2020-January-08, 09:30

the oddity that drives me insane is that say there has been an auction and I have been been bidding hearts and ultimately I allow the opps to succeed in 4spades and then I double 4 spades the GIBs will then bid 5 hearts down a ton where as spades would have been down 1 for a good score ... ergo don't double
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#6 User is offline   msjennifer 

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Posted 2020-January-08, 10:49

sir, Robots are bozos most of the time..We had made three tricks and all the robot had to do was cash the two winners for one down in 3NT. Instead of cashing the winners the Robot SHIFTED to another suit and so 3NT was scored with one overtrick
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#7 User is offline   PhilG007 

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Posted 2020-January-08, 14:37

It should here be remembered that the GIBs like any AI are programmed by humans and humans are imperfect.
Its best to approach them with a healthy scepticism and appreciate they are as fallible as their human creators.
"It is not enough to be a good player, you must also play well"
- Dr Tarrasch(1862-1934)German Chess Grandmaster

Bridge is a game where you have two opponents...and often three(!)


"Any palooka can take tricks with Aces and Kings; the true expert shows his prowess
by how he handles the two's and three's" - Mollo's Hideous Hog
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#8 User is offline   johnu 

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Posted 2020-January-09, 00:41

View Postmsjennifer, on 2020-January-08, 10:49, said:

sir, Robots are bozos most of the time..We had made three tricks and all the robot had to do was cash the two winners for one down in 3NT. Instead of cashing the winners the Robot SHIFTED to another suit and so 3NT was scored with one overtrick

You are such a lucky player. :) Usually GIB does that with the cashing trick in a small slam or grand slam while going for the 2 or 3 trick set, and letting the impossible slam make.
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#9 User is offline   dsLawsd 

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Posted 2020-January-09, 15:04

GIB is not that bad and sometimes impressively accurate.
But if I had to improve the program I would first have opening leader pick partner's suit with support especially at a suit contract.
I do not know how to train a robot to not bid one more when competition only is in order, but perhaps the simulation being made by the software could be tinkered with to settle for a pass.
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#10 User is offline   barmar 

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Posted 2020-January-10, 09:51

In its current design, it's really hard for GIB to be able to tell the difference between "just competing" and bidding with extra strength. Kind of like many beginning players.

#11 User is offline   pilowsky 

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Posted 2020-January-11, 19:49

Thanks for that insight barmar, as a 'beginning player' I often wonder how you went about designing GIB. In the following hand - that I played as South in an ACBL daylong GIB (EW) was trapped into competing up to 3XX - 760 (100%) for NS. https://tinyurl.com/tvvjnbu. I felt safe redoubling knowing that the robot system card states that 3 is the limit for takeout. Your post raises the interesting question: when does Alan Turing decide that a Bridge player is no longer 'beginning'? Yes, I know, South with 12HCP, 15TP is 'too strong' for a preempt'. Well, just to let the cat out of the bag, this is one flaw in the GIB system, GIB always supports preempts when it shouldn't (at least according to the rule of 17) - as in this case. If I really had only 7 points we would definitely not make 3, which is why, I suppose, GIB is programmed to double. Everyone in this discussion is correct. But a program is still a program. GIB is not 'intelligent' it does not 'learn' it cannot be 'taught' even my Poodles are smarter. Fortunately, as with any computer program, it can be 'beaten', in the sense that one can score better than 50% sometimes if one learns its responses. Just like normal Bridge! Sadly, I did not get a WDO from the robots - can't have everything - now there's a suggestion for the software - maybe just for the Prime Club? As with most companies domiciled in Vegas - the 'house always wins' in the long run. You might get masterpoints - but they get the money!

Fortuna Fortis Felix
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#12 User is offline   barmar 

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Posted 2020-January-12, 23:54

View Postpilowsky, on 2020-January-11, 19:49, said:

Thanks for that insight barmar, as a 'beginning player' I often wonder how you went about designing GIB.

We didn't. It was originally written by Matt Ginsberg, an AI researcher, over two decades ago. You can find an article about its original design here: https://citeseerx.is...p=rep1&type=pdf

BBO later purchased the code from him. We've done minor tweaks to the code, but most of our work has just been to improve its bidding rule database.

I suspect many human players would also double in an auction like that. Your partner opened, you have a maximum raise (although the heart length is not much help on defense), and a sure trump trick. West got unlucky that East had opened on minimum strength and South preempted with opening strength. Although if East had full opening values and South had a more typical preempt (swap A and Q), EW can make game and NS only go down 1, so the double is still a loser.

What's the rule of 17 for supporting partner's preempts? I think most people simply play that they usually raise with 3-card support and some shape -- a singleton in the opponents' suit is a plus. North's hand looks like a fine 3 bid to me.

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