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Bidding from the twelfth dimension

#21 User is offline   smerriman 

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Posted 2024-July-02, 19:36

The description of 4 is buggy, showing 6 clubs but only 5 diamonds. See here and the thread I linked to inside that for some more details of the likely cause. (There are lots of other fun preference issues around too, like this one caused by a programmer's typo, and this one where it gives preference to a 2 card suit over a 7 card suit..)
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#22 User is offline   1175 

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Posted 2024-July-04, 13:59

The Robot clearly violated the explanation here:



Fourteen tables had a completely normal auction, with West making 8 (twice), 9 (eleven times), or 10 (once) tricks depending on the declarer play and defense of the human and Robots:



When I play the duplicate IMPs with the Robots, I have a goal of returning a "clean sheet" (sixteen plus scores), something that I manage to accomplish maybe once every two weeks. With fourteen plus scores before this hand, I just about crashed out when I decided to make a 2 balance:



Needless to say, I don't like the 2 call (not the type of suit I want to play a 4-3 fit in). Down 2 (-200) would have given me the bottom North-South score, and an IMP loss. Fortunately, the Robot misdefended yet again, with this position the last opportunity for a two-trick set (East on lead at trick ten, and the defense having taken 5 of the first 9 tricks):



East played the K, so I only needed (to hold the contract to down 1) 3-3 hearts, and the hand with the A to have both of the missing spades. Despite numerous chances for the defense to score more than three heart tricks, it failed to do so, and the favorable lie at the end position (plus the error by the Robot) allowed me to escape for down 1 (+1.5 IMPs, and better than every North-South score, except the one at the table where the auction shown in the hand diagram occurred (+50 and +5 IMPs for North-South).

At the table where South threw in the creative 1NT overcall, I don't have anything good to say about the 2 bid by West (again, the auction has already revealed the best fit for East-West - diamonds). Given the vulnerability, I might have chances a double with the West hand. I particularly object to the 2 ("4- ; 4+ ; 4+ ; 21- HCP; 15-22 total points") and 3 ("4- ; 4+ ; 3+ ; 4+ ; 21- HCP; 15-22 total points") bids by East, with only 12 HCP (opposite a passed hand, no less, where the likelihood of West holding a hand that makes 3NT a good contract seems remote). Passing 2NT looks absolutely clear.
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#23 User is offline   1175 

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Posted 2024-July-05, 22:08

I wonder if the advanced Robot would do any better with this hand:



Two questions here:

What would you bid after?



What would you bid after?



I will update the hand later, but the free Robot would pass both of those auctions, the latter of which I particularly don't like given the concentration of values in partner's suit.
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#24 User is offline   smerriman 

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Posted 2024-July-06, 23:20

View Post1175, on 2024-July-04, 13:59, said:

With fourteen plus scores before this hand, I just about crashed out when I decided to make a 2 balance. Needless to say, I don't like the 2 call (not the type of suit I want to play a 4-3 fit in).

A hand that bids 2 now and not before doesn't exist to the robot (the opponents ending in 1NT is meant to be one of the worst times to balance). The only logic the free robot has after that is bidding 4 card suits up the line. As usual, the proper robot would see that pass is clearly better, so this one's just down to what you paid for.

View Post1175, on 2024-July-04, 13:59, said:

At the table where South threw in the creative 1NT overcall, I don't have anything good to say about the 2 bid by West (again, the auction has already revealed the best fit for East-West - diamonds). Given the vulnerability, I might have chances a double with the West hand. I particularly object to the 2 ("4- ; 4+ ; 4+ ; 21- HCP; 15-22 total points") and 3 ("4- ; 4+ ; 3+ ; 4+ ; 21- HCP; 15-22 total points") bids by East, with only 12 HCP (opposite a passed hand, no less, where the likelihood of West holding a hand that makes 3NT a good contract seems remote). Passing 2NT looks absolutely clear.

None of this sequence is really defined at all, given 1NT doesn't exist; it has no idea what to do after 1NT, and is again using fallback rules like bidding suits up the line. Continuations after undefined bids isn't really something GIB can handle, though of course the proper robot would stop and pass 1NT before any of this started (penalty double is fully undefined).

View Post1175, on 2024-July-05, 22:08, said:

What would you bid after..

With a human, maybe 4NT in the first case to pick a minor, and 5 in the second. But the former isn't part of its system, and 4NT in the latter is totally undefined; it's not passing because it thinks that is best, but because that's the only option it has to choose from (so yes, even the proper robot will pass both).
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#25 User is offline   1175 

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Posted 2024-July-07, 11:27

View Postsmerriman, on 2024-July-06, 23:20, said:

None of this sequence is really defined at all, given 1NT doesn't exist


I would tend to play that as the two lower unbid suits by a passed hand (and it wouldn't seem like much of a stretch to make that part of the system).

View Postsmerriman, on 2024-July-06, 23:20, said:

(penalty double is fully undefined).


I will have to remember that as a way of confusing the Robot :) (I assume it can make penalty doubles of ordinary strong NT overcalls).

View Postsmerriman, on 2024-July-06, 23:20, said:

With a human, maybe 4NT in the first case to pick a minor, and 5 in the second. But the former isn't part of its system, and 4NT in the latter is totally undefined; it's not passing because it thinks that is best, but because that's the only option it has to choose from (so yes, even the proper robot will pass both).


Sounds like the system could define a few more sequences, especially for takeout bids when the opponents preempt. I didn't save the exact South hand (meaning the spot cards), but South held A, x, AJxxx, Qxxxxx (a good hand for a bidding challenge, as slam makes in either minor).
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#26 User is offline   1175 

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Posted 2024-July-07, 13:56

I had a different hand all written up (wondering why the explanation gave South so many points), before I eventually scrolled up and saw that South had opened 1 with a 3-4-3-3 7-count).

I found this hand a bit tortuous - the bidding shown didn't occur at my table, but I also ended up in 3 (on a different auction) and made it (the only North-South with a plus score). East-West played spades at three tables (making 2, 3, and 4), and one other North-South played diamonds, but at the four level (down 2). The other ten tables all played 4, going down 1 (five times), down 2 (three times) and (one time each) down 3 and down 4. While 4 represents a challenging contract, the defense (double dummy) can't beat it.



Yes, South can't pass 3. I probably would have bid 4, and then interpreted 4 by North (what I assume the Robot would bid next) as a cuebid for diamonds. I really don't like the 3 bid. The Robot should let South know about the 8-card major suit fit.

Most North-South pairs had no problems getting to 4 (only problems making it), but that included some NT bids without a stopper, as shown in these auction (the first occurred four times, the second three times):




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#27 User is offline   1175 

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Posted 2024-July-07, 14:42

Does the Robot consider suit quality when determining whether or not to bid (I assume not).



As usual, I will dispense with the alternate realities first. Three Souths shot themselves in the foot with this auction (down one at two tables, and actually making on a defensive error - not by the Robot, at the other):



At one table, South had his doubling shoes on (down 3). West should have left 3X in, since it happens to make (with 2 making 3 the "optimum" result on the hand):



The other twelve tables saw the auction shown (except at my table, where I doubled 4 - it absolutely shocked me that no other South doubled this), going down 3 each time (again, except at my table, where a misplay by declarer resulted in a fourth undertrick).

Analysis time. I wouldn't consider bidding 2 (over 1 at this vulnerability (missing KQJT8, not to mention the other flaws with this hand). I also wouldn't consider bidding with the East hand on this auction (East knows that West has six hearts, and that West knows that South has four hearts). In fact, this auction would make me less likely to want to bid 3 than at the tables where South bid 1NT instead of 1. Note that the explanation for East says "4+ ; 1- ; 13-16 total points" (not even close to that). I guess I should ask why East bids 3 (especially since it doesn't have the values for that bid). I would (of course) pass 3, but I suppose that West thinks that East can't have five or more clubs since East didn't act over 1. The 3 bid seems completely insane to me (according to the system, though, it shows no extra values, so it just represents another way to get into trouble :) ).
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#28 User is offline   1175 

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Posted 2024-July-09, 01:53

I will refer to this post as "nuisance bids" (all of the bidding from the twelfth dimension came from Humans on this hand).



At thirteen tables, North-South never entered the auction, and East-West bid relatively competently to the heart slam, which easily makes despite the 5-0 trump break for -980 and -1.5 IMPs to North-South.

Three Souths entered the auction, each with different bids. From least to most successful:



I have no idea what the Robot intended to do after 3. The 2 bid by South almost worked (assuming East would have passed 3NT), but North ended up bidding 4 (I don't know why when South "showed" only three spades - I would want to know South's "minor"). This should have gone down 6, but a defensive error let North-South escape for -1100 (-4.5 IMPs).



This South simply bid his longest suit. I don't know what options the Robot has here (I would expect East to leave in any sort of double), but Pass looks entirely wrong (I would probably just shoot out 6NT as West over 3). Once again, the defense slipped a trick (easy to understand when South has nothing close to his bid), and North-South ended up down 7 (-350, a score I haven't seen for a while) for a gain of 10.6 IMPs.



At the final table, South showed the major suits (another bid I did not consider). I guess this auction answers my question about the continuation after Lebensohl. East-West charged into the heart slam despite the "known" 5-0 break. Does the Robot just ignore opposition bidding here (and in similar cases) as far as selecting a trump suit? I would probably try 6NT (which also makes) rather than play against a known 5-0 break. Anyway, perhaps caused by the bidding, the Robot made two separate errors in the declarer play, and managed to go down 2 (+100 - the only plus North-South score, and +13.8 IMPs to North-South).
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#29 User is offline   smerriman 

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Posted 2024-July-09, 03:09

View Post1175, on 2024-July-07, 14:42, said:

Does the Robot consider suit quality when determining whether or not to bid (I assume not).

Yes, suit quality is measured on a 9 point scale described here.

Here West is told it needs quality >= 5 (twice rebiddable) to bid 2, which it does. East has too many points to consider passing. Then West has too many points to pass, and so on.

All of these are non-issues; the real robot passes instead of bidding 2; if you force a 2 bid, the real robot passes instead of bidding 3; if you force it to bid 3, the real robot passes instead of bidding 3. The only issue here is that BBO have intentionally weakened the free robot, and that's the one you're playing with.
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