NABC Coaching Session
Working Around GIB's Deficiencies
On Sunday, March 4, at 1PM US Eastern Time (7PM Central European Time), we had a special 1 hour teaching session with star player BBO Star JDonn (Josh Donn). The topic was MP and Robot strategy, with a focus on working around some known GIB deficiencies. The goal was to help players planning to play ACBL's Spring NABC Online Individual. For the BBOers who were not able to attend the lecture, let's dive into the review now.
Good morning, or afternoon or evening depending where you are. In anticipation of the upcoming online NABC event, I thought I would try something a little different this week. I want to discuss a topic that would be most helpful to players entering this event, especially those who are a little less experienced playing with GIB, BBO’s bridge-playing robot. Before I start, please keep any questions on hold until I finish in about 30 minutes, then send them along to Diana_eva or Aurora. They will ask me in front of everyone and I will do my best to answer.

As anyone who has played regularly with GIB knows, GIB is not a perfect player. There are holes in its bidding system, and it has a weird style in certain areas. BBO is regularly working on improving GIB’s bidding system and judgment, but there is much work to be done. So today, I want to talk about some of the areas where GIB needs to be improved, and how the human player can account for them to avoid disasters. All of the hands I will show came up for actual users.

The first area I want to discuss is limit raises. Here is a hand that came up recently in actual play for a user. You hold ♠Kxx AJT9x xxx ♣Ax. You open 1, and partner bids 3, a simple limit raise.



What do you do?

Well let me show you the full hand. This is what happened to a player.



As you can see, GIB made a limit raise on a hand that most humans would recognize is clearly worth a game force. Why did it do this?

There are a few reasons having to do with how GIB counts its points, that it doesn’t appreciate the extra trump length enough and that it downgrades the AQ doubleton because of having honors in a short suit. But "why" it happens is not really my point. Just know that it happens. So when your robot partner makes a limit raise, in particular one that shows a 9+ card fit, simply accept it no matter what your hand is. If the user had done so on this hand, he wouldn’t have missed an easy game.

The second area I want to discuss is "double and bid" hands.

As I think we all know, when an opponent opens the bidding, you might be too good to make a simple overcall. This is especially likely to happen when playing in the online NABC event, since the human player is programmed to have the best hand at the table. In that case, you double and then bid your longest suit. However, GIB thinks takeout doubles show support for all of the unbid suits, and it doesn’t change that assumption even when you bid again to show a big hand. So when you have a big hand without support for all the unbid suits, it behooves you to choose a different strategy when playing with GIB.

What different strategy might that be? I would usually recommend just making a simple overcall, even on a heavy hand.

Here is an example that a user sent in. Holding ♠AKJ Jx KQTxxxx ♣A the bidding went:



And here's the full hand:

 

Note that on this auction, GIB opponents bid and responded, so partner probably doesn’t have much anyway. The auction spiraled out of control, but in particular notice that GIB North assumed partner had spade length even after the "double and bid" which most human would just take as a good hand with diamonds.

If south had simply overcalled 3, he could rebid diamonds if he chose when the auction came back on the next round, and all would have been well:



Even if he missed a game, at least he would be plus instead of being stuck in a ridiculous contract by his partner.

A quick note. If your suit is a major suit instead of a minor suit on a hand similar to this one, you might just overcall 4 of the major at your first opportunity. Even if partner assumes it is a weak bid it is unlikely to matter, since you don’t often have a slam after an opponent opens the bidding. That gets you to game, and partner won’t stick you in any other suit.



So if this were my hand, I would just overcall 4♠ with GIB, not risk doubling first.

Let me discuss one more thing, a specific auction in fact.

When you open 1 and GIB responds 2♣, or vice versa, the 2♣ bid is marked as being forcing to game. Warning, that does not match how GIB thinks! GIB will pass a 3♣ rebid by either player, so either 1 2♣ 3♣, or 1 2♣ 2N 3♣. Sorry that what GIB plays does not match the explanation in this instance, but be warned. If you don’t want to be dropped in a partscore, then make another bid.

Here's a real hand. This player learned the hard way, holding ♠Kx Kxx AKxx ♣Jxxx.



So what could they have done differently? I recommend a 2NT rebid. I think on the actual hand GIB would have rebid 3NT. Even if GIB did rebid 3♣, the player could then have rebid 3NT, needing only AK-sixth of clubs and a major suit lead to make.



Note: you can take advantage of this part of the system holding an invitational hand with clubs. If GIB bids 2♣ then 3♣, he is invitational, not game forcing. And likewise, if you are invitational with clubs and partner opens 1, you can feel free to respond 2♣ and then bid 3♣ , knowing GIB will pass if he is minimum.

Don’t be scared that GIB never has what it says it has. The instances I describe are exceptions, not the norm.

Let me note however, if GIB makes an unexplainable bid, or something you think is programmed incorrectly, you can always report to BBO and it will be looked at. Here is how you send it in. After the hand is finished, click on the My Results tab on the right of the screen. Click on the hand you want to send in from the list of hands you have played. Then on the bottom, click the Options button, mouse over Export Deal, then click Send Robot Report. You can type a short note about what went wrong, send it in, and someone at BBO will give it a look.

I hope to see everyone here entering the online NABC event. It starts tomorrow! It should be a lot of fun, doesn’t cost much money, and gives away lots of masterpoints. And the best part? You can play at any time of day while it is ongoing. More information is available on the News Feed on the BBO home screen. Have fun in your adventures playing with GIB, and best of luck to everyone.

I will take questions now.


Q1: Are all limit raises by gib with 4 card support?
A: When it raises a major suit directly, 1 P 3 or 1♠ P 3♠, that promises 4+ card support. With 3 card support it starts with 1NT forcing, like 1♠ P 1NT P 2 P 3♠

Note: With the 3 card limit raise you shouldn't be insanely aggressive, it usually has a normal hand. But the 4 card raise I would always accept.

Q2: Can you talk a bit more about the first hand, where you had a min hand and 8 losers, do you believe you'll be better off to pass the limit raise or not?
A: I will circle back around to it.



I am saying that with this hand, or any hand, I would accept the limit raise. This was an example from actual play, GIB is too good to make a limit raise but did so anyway. But if it was a 3 card limit raise, I would pass since I'm minimum. If you can imagine in your head, switching around dummy's hearts and clubs And game is much worse.

Q3: There are quite a few questions on how gib defends. Does GIB show attitude, or count on the opening lead? or neither?
A: How GIB defends is a difficult and sometimes frustrating topic.

Unfortunately neither, GIB doesn't really signal. You have to make your best play without the help of a useful signal. Even in real life, when to give an honest signal to help partner, and when to avoid signalling so you don't help the opponents, is not a simple topic.
Sorry there isn't a more satisfying answer but GIB doesn't really signal.

Q4: Follow up on this. Would GIB fall for a falsecard? Does declarer carding matter?
A: You should certainly falsecard against GIB because it can't hurt. But giving false count won't fool GIB, it won't pay attention.

The falsecards you should make are "mandatory" false cards to give a losing option in the suit. For example, you have QTx of a suit to the right of dummy, dummy has A9xx, declarer leads of dummy, you play low, he plays the jack and it holds. Next declarer lays down the king. You should drop the queen on this trick, so declarer doesn't know if you have QTx or Qx and might finesse back into your 10.

GIB can fall for something like that, and if you don't do it you have no chance. But as far as giving false count, you can do it if you want, but it won't help, or hurt.

Q5: Do you open 11-12 point hands?
A: I do. Remember you have the best hand at the table in these tournaments, so if you have 11 neither opponent will have more than that. The hand will usually belong to your side, so open it.

Q6: On defense, GIB is fond of leading short suits and is very good at getting a ruff on defense. But when I lead a short suit and my GIB partner gets in, it often seems reluctant to give me a ruff. Is there some reason for this?
A: Sounds like bad luck. If you can get a ruff GIB will tend to give it to you. Not sure what else to say about that. Leading short suits is a good idea with GIB, since it will assume that is what you are doing most of the time. So just keep trying.

Q7: GIB makes passive safe leads vs NT. Does GIB assume my opening leads are the same?
A: I believe it does, to the extent that it knows the distribution of the hand.

I can tell you BBO has been swarmed over time by reports from players complaining that GIB doesn't return their lead. So that suggests GIB is playing for partner to be making passive leads. That's why if you can stand to, it's good to adopt that style. Of course you aren't likely to be defending too often in this event since you have the best hand, but you never know.

Q8: I seem to get a LOT of 4-1 trump breaks playing with GIB. Are the deals completely random?
A: Yes they are random.

It's the same complaint people make in real life with computer dealt hands. The fact is, hands shuffled by people are TOO balanced and even due to poor shuffling, cards tend to stay together in the same suits. The hands on the computer are how random hands are supposed to be. You are getting the expected amount of bad breaks.

Q9: I often try to make a light balancing bid or double or a bid or double as a passed hand but it seems like GIB thinks i have full values for this. Does GIB not take into account that I am a passed hand and/or just balancing?
A: Yeah balancing is another subject I could have easily discussed today.

Unfortunately, GIB does not have a good concept that balancing actions are lighter than direct actions. It tends to hang you for balancing. I recommend avoiding it whenever possible. That should be fixed down the road, but for now be wary about balancing, and never on a light hand.

Q10: In a contested auction where you are bidding a minor .... your P bids 3/♣ and you jump to 5/♣ to avoid a turned down invitation why does GIB jump to 6 with an aceless hand?
A: If partner bids 3 on some auction, make sure you check the definitions of 4 and 5 before choosing one of them.

Maybe 4 fits your hand better even if you want to be in game. Better for GIB to know what you have and hopefully make the right decision than to hang you because it thinks you have a better hand.

Q11: Should human try to beat GIB to blackwood? GIB not the greatest at judging best final sport after gib uses BWD
A: Sure if you can simplify the auction and take charge, it's always a good idea to do so. GIB is ok with blackwood as far as avoiding slam off 2 aces and bidding it off 1 ace. Not so good at finding 7 when all the aces are held though. Luckily grand slams are relatively uncommon.

Q12: And somewhat related: Cuebids. Both sides are bidding. I want to know if partner has a stopper in their suit. Does GIB understand a cuebid in this context. I seem to have very erratic results with this problem.
A: Cuebidding opponents suit in a competitive auction is another place where you want to make sure to check the meaning of the bid before making it. Some places, where humans would usually think the cuebid is asking for a stopper, GIB thinks your cuebid is showing a stopper, so you have to try something else.

Q13: What does GIB play over partner's preemptive opening? How does it respond?
A: Over preempts GIB plays fairly simply. A new suit is forcing. 2NT is feature ask, if GIB has an A/K/Q to show and anything more than a bare minimum, it will show it. That's pretty much it.

There used to be a problem when the preemptor would bid blackwood like 2♠ P 2N P 3♠ P 4♠ P 4NT, but that has been fixed.

Ok I think that will be it for today. I hope everyone has fun in the online ACBL event. Don't forget to sign up today!


Click here for notes from our previous lectures.




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