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Computer dealt hands - with a hiccup ACBL

#61 User is offline   helene_t 

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Posted 2009-December-08, 09:54

blackshoe, on Dec 8 2009, 04:40 PM, said:

If I'm not mistaken, the table TD determined that the two boards were indeed identical down to the last pip before he made his table ruling. Given that knowledge at that time, would you still make the same ruling?

No I don't think so.

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If you did so rule (let's say you didn't know they were identical) and it later turned out your assumption was wrong, is that not TD error, requiring you to adjust the score treating both sides as non-offending?

Yes I suppose so.
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#62 User is offline   axman 

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Posted 2009-December-08, 11:41

blackshoe, on Dec 8 2009, 09:53 AM, said:

I take your point about setting a precedent, Helene, but as Gordon said, here we have a player who has extraneous information about board ten. Are we to simply to give an artificial adjusted score on this board, and hope that anyone else who recognizes the problem calls the TD so he can get the same, or do we let them play on, with that extraneous knowledge?

The problem is that once the player gives any indication that something is amiss there is the probability that the partner will draw inference. Certainly, once the TD is summoned I am confident that I would include that inference in the reasons for the call. And, if I will then so will others.

And thus is the situation:

Until the player gives any inkling of his suspicions, what he has are suspicions. These suspicions might eventually be born out as fact or fancy. If the hand was indeed legitimate then he is entitled to any outcome that he earns at his own risk. If not legitimate then no one is [or at least ought to be] entitled to earn any outcome.

However, once the inference comes available the defenders are not in a position to earn anything because there has been a communication to the PARTNER. Actually, the law approaches being unsuitable for remedying this situation- and to the best that I am able to discern the only applicable passages lie in L16/73.

From personal experience there was the occasion in a shuffle and play swiss when I held a hand in round 4 that I would have been willing to wager a large sum was identical to a hand from the same board that I held during R3 [having retained the same table and thus the same boards for those two rounds]. However, while willing to wager on my hand I was not nor would not be willing to wager any sum on the other hands sight unseen.

On the first occasion I deviated from system which led to an apparently thin game. On the second occasion I duplicated my efforts to the same effect. After completion of play I informed the TD that the board was identical to the previous round. This had several effects [a] he accused me of cheating [b] he ascertained that the other table had in fact not shuffled it (the other boards were ok) prior to play [c] the result was canceled and a substitute was played.

As for my personal example I feel that [with the exception of the TD behavior] it was handled as it ought to be handled. Though in law that assertion is questionable. I am unable to find justification for correcting the shuffle once the board is played. [L6D2 specifies that the result be canceled <the board was played in the previous session/round> but does not specify a basis for correcting the shuffle].

Notably L15B specifies:
B. One or More Players Have Previously Played Board

If any player plays a board he has previously played, with the correct opponents or otherwise, his second score on the board is cancelled both for his side and his opponents, and the Director shall award an artificial adjusted score to the contestants deprived of the opportunity to earn a valid score.

That the result be canceled but does not provide a mechanism for correcting the shuffle.
Bridge is a game and I will remember that its place in my life is that of a game. I will respect those who play and endeavor to be worthy of their respect. I will remember that it is the most human of activities which makes bridge so interesting. And in doing so I will contribute my best and strive to conduct myself fairly. -Bridge Player’s Creed
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#63 User is offline   bluejak 

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  Posted 2009-December-08, 14:34

When a board is cancelled in a team game it is normally a matter of regulation not Law what is done to the actual board.
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#64 User is offline   jdonn 

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Posted 2009-December-08, 14:55

Helene has nailed it. Why is a director adjusting a board based on what he considers an extreme coincidence? There is no way to know where to draw the line.

What if the 4 hands were the same as the other board but completely rearranged (north and east hands from the other boards are partners on this one)?

What if just one pip is different?

What if the hands were the same as the previous board but with the hearts and diamonds of all players reversed?

These are questions that can't be fairly answered. The fact is even if the board was completely identical to a prior board, then even though it seems like a computer error that layout is as likely as any other particular layout occuring. There is no reason for the director to do anything.

The player doesn't have extraneous information. All we can prove is he thought he had extraneous information but may have made a lucky guess.
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#65 User is offline   pran 

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Posted 2009-December-08, 15:48

blackshoe, on Dec 8 2009, 04:40 PM, said:

If I'm not mistaken, the table TD determined that the two boards were indeed identical down to the last pip before he made his table ruling. Given that knowledge at that time, would you still make the same ruling?

If you did so rule (let's say you didn't know they were identical) and it later turned out your assumption was wrong, is that not TD error, requiring you to adjust the score treating both sides as non-offending?

In order to answer your question here you will first have to consider the following situation:

In a Mitchell or Howell event all deals have been dealt after solid shuffling by the players at the respective tables. There is just one copy of each deal and there is no reason to suspect any improper handling of the cards by any player.

Eventually it is discovered that two different deals are almost identical, for instance only differing in the allotted direction for the respective hands. And the way the dealing has been performed this similarity has evidently happened just by chance.

Do you cancel one of the boards?

Whether yes or no, on what legal ground?
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#66 User is offline   Echognome 

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Posted 2009-December-08, 16:06

jdonn, on Dec 8 2009, 12:55 PM, said:

Helene has nailed it. Why is a director adjusting a board based on what he considers an extreme coincidence? There is no way to know where to draw the line.

What if the 4 hands were the same as the other board but completely rearranged (north and east hands from the other boards are partners on this one)?

What if just one pip is different?

What if the hands were the same as the previous board but with the hearts and diamonds of all players reversed?

These are questions that can't be fairly answered. The fact is even if the board was completely identical to a prior board, then even though it seems like a computer error that layout is as likely as any other particular layout occuring. There is no reason for the director to do anything.

The player doesn't have extraneous information. All we can prove is he thought he had extraneous information but may have made a lucky guess.

Let's be somewhat practical. The reason the director's knew that the board had been fouled is because the second board did not match the hand records when they checked. It had, in fact, matched the first board, but rotated. I am not 100% sure, but I'm pretty sure it was due to human error, not computer error.

So taking it as a fact that the board was fouled, how do you rule? Play on because the board is not identical? Doesn't that sound silly?
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#67 User is offline   gordontd 

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Posted 2009-December-08, 16:11

jdonn, on Dec 8 2009, 09:55 PM, said:

Why is a director adjusting a board based on what he considers an extreme coincidence?

Because he doesn't consider it an extreme coincidence - the likelihood is so much greater that there was a shortcoming in the dealing process. If one were completely satisfied that there was no such shortcoming, and the two (identical but rotated) boards were properly dealt, then the board results should stand. But it's so unlikely that it's reasonable to doubt it in the absence of very strong supporting evidence.
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#68 User is offline   jdonn 

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Posted 2009-December-08, 16:11

Echognome, on Dec 8 2009, 05:06 PM, said:

jdonn, on Dec 8 2009, 12:55 PM, said:

Helene has nailed it. Why is a director adjusting a board based on what he considers an extreme coincidence? There is no way to know where to draw the line.

What if the 4 hands were the same as the other board but completely rearranged (north and east hands from the other boards are partners on this one)?

What if just one pip is different?

What if the hands were the same as the previous board but with the hearts and diamonds of all players reversed?

These are questions that can't be fairly answered. The fact is even if the board was completely identical to a prior board, then even though it seems like a computer error that layout is as likely as any other particular layout occuring. There is no reason for the director to do anything.

The player doesn't have extraneous information. All we can prove is he thought he had extraneous information but may have made a lucky guess.

Let's be somewhat practical. The reason the director's knew that the board had been fouled is because the second board did not match the hand records when they checked. It had, in fact, matched the first board, but rotated. I am not 100% sure, but I'm pretty sure it was due to human error, not computer error.

Sorry I didn't see that, if I had then that's of course different. That's what I get for entering a thread late.
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#69 User is offline   jdonn 

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Posted 2009-December-08, 16:12

gordontd, on Dec 8 2009, 05:11 PM, said:

jdonn, on Dec 8 2009, 09:55 PM, said:

Why is a director adjusting a board based on what he considers an extreme coincidence?

Because he doesn't consider it an extreme coincidence - the likelihood is so much greater that there was a shortcoming in the dealing process. If one were completely satisfied that there was no such shortcoming, and the two (identical but rotated) boards were properly dealt, then the board results should stand. But it's so unlikely that it's reasonable to doubt it in the absence of very strong supporting evidence.

You make it seem like you don't know what a coincidence is...

You say essentially "he doesn't consider it a coincidence, he just believes what occured is so unlikely that it almost couldn't be true." That would be like me saying "this is not an online bridge forum, it's just an internet-based vehicle for people to discuss bridge-related topics."
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#70 User is offline   gordontd 

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Posted 2009-December-08, 16:59

jdonn, on Dec 8 2009, 11:12 PM, said:

You say essentially "he doesn't consider it a coincidence, he just believes what occured is so unlikely that it almost couldn't be true."

No. I say that this explanation for what occurred is so unlikely that I believe there's another explanation. You think that's what a coincidence is?
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#71 User is offline   aguahombre 

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Posted 2009-December-08, 17:28

this is like the word "preemptive" we discussed a while back.
"coincidence", of course. coincidental, due to error by man or machine, or due to a random miracle.
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#72 User is offline   barmar 

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Posted 2009-December-08, 23:07

bluejak, on Dec 6 2009, 05:59 AM, said:

The computer dealt the same hand twice.

Apparently not, according to Echo's post.

#73 User is offline   pran 

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Posted 2009-December-09, 02:44

Echognome, on Dec 8 2009, 11:06 PM, said:

Let's be somewhat practical.  The reason the director's knew that the board had been fouled is because the second board did not match the hand records when they checked.  It had, in fact, matched the first board, but rotated.  I am not 100% sure, but I'm pretty sure it was due to human error, not computer error.

So taking it as a fact that the board was fouled, how do you rule?  Play on because the board is not identical?  Doesn't that sound silly?

This is not what we have been told:

In a follow-up OP told us that: The computer dealt the same hand twice.

(In another post we have been told that the computer printouts were checked.)

Of course if hand records reveal that the board in question is not according to the deal the computer had created then that board has not been dealt in accordance with law 6 (more precisely in this case: With Law 6E4). Thus the board is fouled, end of story.

(And the computer program is probably in the clear)
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#74 User is offline   pran 

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Posted 2009-December-09, 02:48

jdonn, on Dec 8 2009, 11:11 PM, said:

Sorry I didn't see that, if I had then that's of course different. That's what I get for entering a thread late.

Relax.

You didn't see it because it wasn't there.
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#75 User is offline   cherdanno 

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Posted 2009-December-09, 03:42

If you really think this is coincidence then you have no idea how big the number of possible bridge deals is. The fact that every other deal is equally unlikely doesn't matter: for the given deal there is an alternate explanation (same board dealt twice) that is not completely unlikely which does not exist for other deals. That alternate explanation is more likely than the coincidence by a huge factor.

Btw, I wouldn't let the earlier results stand. Even if these players didn't notice it explicitly, they may have benefitted without realizing it (e.g. "learning" how to play a certain suit combination on the previous board).
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#76 User is offline   campboy 

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Posted 2009-December-09, 04:18

helene_t, on Dec 8 2009, 11:37 AM, said:

- We don't want to create precedence for directors with a bad intuition for probabilities (and most everyone has very bad intuition for probabilities) to reshuffle boards whenever he thinks something looks strange. For every genuine bug in a dealing program there will be literally thousands of false positives.

I am pretty sure it is the other way around. The chances of having two consecutive boards sufficiently similar that anyone would think twice about it is likely to be much smaller than any reasonable estimate of probability of machine failure. I've seen machine failure happen, whereas even the chance that one hand out of the four will be repeated -- which is massive compared to the sorts of situations discussed in this thread -- is in the billions to one.

If I had any other ruling to give where I was 99.9999% sure that my ruling was correct, I'd be very happy. And that number isn't even close to being an exaggeration.
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#77 User is offline   gordontd 

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Posted 2009-December-09, 04:20

aguahombre, on Dec 9 2009, 12:28 AM, said:

this is like the word "preemptive" we discussed a while back.
"coincidence", of course.  coincidental, due to error by man or machine, or due to a random miracle.

My dictionary's definition of coincidental includes the phrase "without any causal connection".
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#78 User is offline   shintaro 

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Posted 2009-December-09, 06:08

:)

Using Duplimate machines we did get on odd occasions hands of 13 13 13 13 dealt this was a bug which was cured by altering from the Old 3 bar coded packs to the now 5 bar coded packs with the updated chip

:)
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#79 User is offline   helene_t 

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Posted 2009-December-09, 06:26

campboy, on Dec 9 2009, 11:18 AM, said:

helene_t, on Dec 8 2009, 11:37 AM, said:

- We don't want to create precedence for directors with a bad intuition for probabilities (and most everyone has very bad intuition for probabilities) to reshuffle boards whenever he thinks something looks strange. For every genuine bug in a dealing program there will be literally thousands of false positives.

I am pretty sure it is the other way around. The chances of having two consecutive boards sufficiently similar that anyone would think twice about it is likely to be much smaller than any reasonable estimate of probability of machine failure. I've seen machine failure happen, whereas even the chance that one hand out of the four will be repeated -- which is massive compared to the sorts of situations discussed in this thread -- is in the billions to one.

If I had any other ruling to give where I was 99.9999% sure that my ruling was correct, I'd be very happy. And that number isn't even close to being an exaggeration.

Disagree.

Sure, the software has all kind of bugs but a fault in the basic dealing algorithm is extremely unlikely, unless it's a ridiculously old program or a home-baked program. OTOH some human error, like merging two deal files that are supposed to be different but are in fact identical, or specifying the seed in a batch file that calls the dealer repeatedly and sometimes twice using the same seed, might happen.

Still I think it is a small chance compared to the myriads of players complaining about weird computer-dealt hands. We have had those discussions on this forum where some people think they can diagnose the BBO dealing algorithm on the basis of their gut feelings based on a few thousand hands, and similar discussions pop up at other forums, as well as IRL clubs.
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#80 User is offline   pran 

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Posted 2009-December-09, 07:50

helene_t, on Dec 9 2009, 01:26 PM, said:

We have had those discussions on this forum where some people think they can diagnose the BBO dealing algorithm on the basis of their gut feelings based on a few thousand hands, and similar discussions pop up at other forums, as well as IRL clubs.

It is a well known fact that the difference between computer "shuffling" and manual shuffling is sufficient for humans to determine with a high probability when a set of deals has been made by computer and when by humans.

The reason is that human shuffling generally is insufficient, resulting in "too many" flat deals.

I once read that the Italian Blue Team was known to "shuffle the spots off the cards" when they had a feeling of lagging behind. The reason for this was that they knew sufficient good shuffling would (correctly) result in a higher proportion of longer suits for which they had an advantage with their system.
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