BBO Discussion Forums: Fouled board - BBO Discussion Forums

gordontd, on 2015-January-07, 03:07, said:

So you have a board that was fouled at one table only and have no further evidence on how or by whom it was fouled.

Do you award 60% / 60% because you have no indication that they fouled it themselves, or
do you award 50% / 50% because you have no indication that the board was already fouled when they received it?

pran, on 2015-January-07, 09:10, said:

I investigate and make my decision based on the balance of probabilities, as required by the law. If you make your general starting point "innocent until proven guilty", you are not following the Laws of Bridge.

In practice I think it unlikely we would come to different conclusions in cases of this nature, but if you habitually start from the wrong point you will sooner or later come to the wrong conclusion.

pran, on 2015-January-06, 16:17, said:

This isn't a court of law. AFAIK, that principle doesn't apply.

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I expect them to do something reasonable, presumably reflecting the most common case, as a default. When it doesn't apply, there should be a way to override it.

It seems like this whole discussion is over whether the default that this particular program uses is "something reasonable". I.e. do you have to override it more often than not?

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If I ever gave the impression that I preferred this default, I did not intend to. All I think I said is that any default score entered by the program is implying some assumption, and sometimes this assumption will be wrong.

So you either have to implement a default and provide a way to override, or leave the score blank and require the TD to fill it in himself in all cases. The latter might be preferable if you're worried about lazy directors who don't investigate, but just always accept the program's default. But there's also a good chance that these directors still wouldn't investigate, they'll just form a habit of entering the same score.

blackshoe, on 2015-January-06, 20:37, said:

Good question. The ACBLscore manual gives the formula and says "The formula for scoring fouled and adjusted boards is the one used by the World Bridge Federation and adopted by the ACBL".

I have found this link on the ACBL site: http://web2.acbl.org...Section%20g.pdf but have not yet succeeded in tracing it back to the parent document of which this comprises Chapter 12 Section G It does not appear to be part of the General Conditions of Contest.

According to the BridgeGuys site "The formula, created by the World Bridge Federation, for scoring fouled boards and those score results needing adjusted scores was adopted by the ACBL in 1990".

I am reasonably confident that the regulation is indeed published somewhere but it may well be in a locked basement somewhere in the Alpha Centauri system.

gordontd, on 2015-January-07, 10:16, said:

You seriously disappoint me by avoiding the questions that should be very easily answered.

You have a fouled board, it has been played fouled at one table only, and however much you investigate you will find no indication that the players fouled the board themselves nor will you find any indication that the board was already fouled when they received it.

So what score(s) do you award? . . . . . (and why?)

barmar, on 2015-January-07, 11:32, said:

No? Well this is indeed a court of (bridge) Law and

Law 12 C 2 a said:

(My Enhancements)

To me "at fault" here means "guilty" (of something), and I see no reason why we shall be less strict about ruling anybody guilty here than we are in (for instance) a criminal court. I feel pretty close to come thinking of the words: "injury", "insult" or even "slander".

All these comparisons of the rules of a game to criminal law are a waste of time and energy. The two are just not comparable.

"Assumed innocent until proven guilty" is a provision of US (and possibly other nations') criminal law. It is not a principle of the rules of bridge. Nor is "guilty until proven innocent," which seems to be a principle espoused by many, including many in law enforcement, in spite of the actual law.

As a TD I start from a neutral position on any question under the rules of the game. I investigate. I base my rulings on the laws and regulations in force and on the preponderance of evidence. And that is all.

pran, on 2015-January-07, 13:38, said:

I'm not avoiding answering anything. I'd award A+/A+ and I think I've indicated as much already. But I'd do it because in such circumstances that's what I would think the balance of probabilities suggest, not because of some misguided notion of "innocent until proven guilty".

gordontd, on 2015-January-08, 01:18, said:

Trying to be careful.

I have seen no evidence [via investigation] that establishes when the hands were switched nor by whom. And thus would not proceed towards ruling on a score.

To put a finer point on it. I have seen many occasions where NS have removed their cards and then N turns the board 180 degrees so that it is oriented 'correctly'-... and then EW remove their cards.

axman, on 2015-January-08, 13:06, said:

But you have to assign a score eventually.

If you have no evidence regarding the actual circumstances, what else can you do but guess what was mostly likely?

barmar, on 2015-January-08, 13:51, said:

You develop evidence before ruling; state the evidence and the reasoning for choosing the evidence when ruling.

We are told that the fouling was discovered after a pair played the board a second time.

Ask, 'What Happened?'

When it becomes clear that they fouled [and how];
....or did not foul it- then work backwards [asking, 'what happened?' etc] until it is evident** the board was not fouled.

Based upon what is found and the confidence level, you are in a position to rule- hopefully in a fair manner.

**it can be conceivable that some third party that wasn't supposed to touch the cards did the deed so you never know to find him

chrism, on 2015-January-07, 11:47, said:

The document you're looking for seems to be the ACBL Codification, found on the ACBL site at Home>About ACBL>Administration. Not sure what the relationship is between this document and the ACBL Handbook of Rules and Regulations, found at Home>Clubs>Club Administration>Club Managers, or between the latter document and the Handbook for Club Directors or for that matter the Handbook for Club Managers, both of which are found at Home>Clubs>Helpful Documents, as is the "Handbook of Rules and Regulations" (but not the Codification). The Helpful Documents link seems to be on every top level page now.

The Codification seems to (occasionally? frequently?) refer to previously published regulations (in particular about fouled board procedures, but iirc there are other regs in this boat) but does not indicate where those are to be found. To be sure, the reference was from a BoD item from 1976, but if the item is still current, then it would be nice to know what the regulation says other than what was changed in the item.

One of the documents I ran across in researching this is titled "2010 <whatever it was>" and annotated "last modified in 2014".

I found "handbook of rules and regulations" links (via the site's search engine) for several different years, making me wonder if this isn't an annual publication.

The formula at your link is a mite confusing. It appears to read: M=N*S/n+(N-N)/2*n, but this can't be right, because the second term will always be zero. Here, M is final matchpoints on the board, N is number of scores on the board, S is the matchpoint score in the group, and n is the number of scores in the group. n must be ≥ 4, or the regulation basically awards set percentages (70%, 60%, 50% in a group of 3; 65% and 55% in a group of two, and 60% in each direction for a group of one). I think that in the two and three groups only one side gets these percentages, and the other gets the reciprocal, but the regulation doesn't actually say that, and I don't remember what ACBLScore actually does in these cases.

The EBU version of this (Neuberg) formula is Match Points = ((M x E) + (E – A))/A where A is the number of scores in the group, E is the total number of scores, and M is the score in the group. Using ACBL's variables, this translates to (SxN+N-n)/n. This leads me to think there's a typo (or 2) in the ACBL's formula.

blackshoe, on 2015-January-08, 16:11, said:

When I teach English club directors about the Neuberg adjustment I try to steer clear of all algebraic representations of the formula, which will only frighten them off. I teach them a simple four-step procedure:

(1) Matchpoint the scores within the groups

(2) Lend every pair a matchpoint

(3) Multiply the result by E / A (number of expected scores / number of actual scores)

(4) Take back the loaned matchpoint

(For peace of mind you could add: (5) check the sum of the NS and EW matchpoints are the same as for every other board)

This is fairly easy to remember and gives them some insight into what is actually going on.

VixTD, on 2015-January-09, 07:54, said:

There is an even easier way to explain Neuberg, it is named "Acherman" (sorry if i have the name slightly incorrect):

Calculate all scores relative to average within the group (e.g. a group of five will have the scores -4 -2 0 +2 and +4)

Multiply each score with the total number of tables and divide with the number of tables within the relevant group:

There you are!

(If the translation is for a total of 9 tables the scores within a group of 5 tables will become
-7,2 -3,6 - 0 +3,6 and + 7,2, or zero based: 0,8 4,4 8 11,6 and 15,2)

Algebra doesn't scare me.

pran, on 2015-January-09, 08:04, said:

I thought that the Asherman correction (however you spell it) gave a different result from Neuberg, and gave rise to much discussion about which was better / fairer. If I understand you correctly the procedure would be:

(1) Matchpoint the board within the group
(2) Subtract the group average from each score
(3) Multiply the results by E/A
(4) Add back a normal average

This seems to give the same result as my method, and I don't see why it should be easier, but if you find it so, fine.

blackshoe, on 2015-January-09, 08:20, said:

It divides classes of trainee directors into two groups: those who revel in it and those who are repelled by it.

I believe Stephen Hawking was told that every equation he included in A Brief History of Time would reduce its sales by a certain percentage.

VixTD, on 2015-January-09, 12:27, said:

It is easy to prove that Asherman and Neuberg are identical.

Since the first introduction of computer aided scoring in Norway (around 1980) we have always scored matchpoints plus/minus relative to average, and then the correction factor for each score is simply: R/S where R is the number of tables in the Result (common) group and S is the number of tables in the Source Group.

I don't think anything can be simpler whether to understand or to use than that?

pran, on 2015-January-09, 12:43, said:

If what you describe is Ascherman (spelt so), then they are indeed identical and my recollection must be false, but in that case why are they referred to as if they were different? It's like arguing about whether you should perform the operation "X + 4 + 2" or "X + 2 + 4".

pran, on 2015-January-09, 12:43, said:

I think a lot of club directors with little maths training would struggle to understand what you meant if you told them to "score this board relative to average".

axman, on 2015-January-08, 14:58, said:

You were replying to a post where said that no such evidence could be found. I was presuming that you already went through that process and came up empty. You still have to come up with a ruling.