[barmar]

jallerton, on 2016-November-02, 01:56, said:

The problem for TDs is that players have a tendency to make self-serving statements. We see this in UI and unintended/intended call situations; MI cases are no different. If two partners give different explanations I would expect one of them to have got the system wrong; in the absence of other knowledge I would assign a 50% probability to each player having got the system right. However, experience shows that when there is a disagreement of this nature, the offending side seem to tell the TD in about 75% of cases than the explanation was correct and than the bidder had got the system wrong. This implies to me that there are regular instances of players bending the truth in order to get a ruling in their favour. Yes, you do not want to accuse players of lying and any statements made to the TD are evidence, but they are not conclusive evidence.

While it may not be conclusive evidence, the law that says to presume MI doesn't require conclusive evidence, just evidence. It's up to the TD to decide how credible the evidence is.

If the pair were having an argument over what their agreement were, and North seemed to admit the misbid reluctantly, I'd agree with your conclusion that it was self-serving. But if he immediately agrees that South was right, it seems like a credible admission.

Regarding the notation on the system card, I suspect most players who use checkback over 2NT use it when 2NT was a jump. I'm not sure I've heard of it being used after a 2/1 response, but maybe that's just my provincial experience. I certainly wouldn't assume that a CC notation regarding jumps to 2NT also applies to non-jumps -- if they have any special agreements about the latter, I'd expect it to be noted explicitly somewhere (maybe only in the notes, if there's no place for it on the CC).

[blackshoe]

barmar, on 2016-November-02, 14:45, said:

While it may not be conclusive evidence, the law that says to presume MI doesn't require conclusive evidence, just evidence. It's up to the TD to decide how credible the evidence is.

The law doesn't require any evidence to presume MI. What it (Law 75) says is "the Director is to presume mistaken explanation, rather than mistaken call, in the absence of evidence to the contrary." So what requires evidence is that it was a mistaken call. If there is no evidence that it was a mistaken call, it is ruled mistaken explanation, even if there's no evidence it was that.

In a case where one partner makes a call, and the other partner explains that call, with or without an alert, and where the explanation does not match the caller's hand, It is up to the pair concerned — which really means it's up to the one who made the call — to provide evidence that he misbid. Of course, the hand itself is evidence — but is it enough? Generally speaking, I would think not. It is enough to require the director to investigate further.

[barmar]

blackshoe, on 2016-November-02, 15:06, said:

The law doesn't require any evidence to presume MI. What it (Law 75) says is "the Director is to presume mistaken explanation, rather than mistaken call, in the absence of evidence to the contrary." So what requires evidence is that it was a mistaken call. If there is no evidence that it was a mistaken call, it is ruled mistaken explanation, even if there's no evidence it was that.

That's what I meant. I could have written "doesn't require conclusive evidence to rule otherwise". But since the law is already clear about which ruling requires evidence, I didn't think it was necessary to restate it here. The point I was trying to make was about what kind of evidence is required -- I was refuting whether the evidence needs to be "conclusive" on its own.

[jallerton]

lamford, on 2016-November-02, 08:54, said:

I agree with jallerton that one just falls back on 21B1(b), and generally assumes MI. If the CC stated "we do not play checkback after a 2NT rebid, whether a jump or not" then that would indeed be evidence to the contrary. If the players could show a system file that states that they "do not play checkback after a 2NT rebid", then that is evidence to the contrary, if and only if they obtained the system file in a short period insufficient to doctor it. If 3C was checkback, then the spade return is automatic, as North must then have 4 spades. One can, I believe, give a weighted score based on the probability of MI, and I think (but gordontd will correct me if I am wrong) that 75% of one off and 25% of making would be a legal ruling. If so, then it might be the most equitable. The actual ruling seems very poor to me, as the principle is that when there is a different explanation on both sides of the screen, the TD will tend to assume that the one that is correct is the one most beneficial to the non-offenders, roughly in accordance with 21B1(b).

I'm not Gordon, but the invitation to correct you is too hard to resist!

The TD has to make a judgement whether there was an infraction or not. If he judges there was not, the table result stands. If he judges that there was an infraction, MI in this case, he proceeds with the next part of the ruling: to assess the damage (if any) caused by the infraction. 75% of one off and 25% of making would be a legal ruling, but only if he judged MI to exist and those were the probabilities he attached to West finding the different lines of defence being found if given the correct explanation.

[lamford]

jallerton, on 2016-November-02, 15:57, said:

I'm not Gordon, but the invitation to correct you is too hard to resist!

The TD has to make a judgement whether there was an infraction or not. If he judges there was not, the table result stands. If he judges that there was an infraction, MI in this case, he proceeds with the next part of the ruling: to assess the damage (if any) caused by the infraction. 75% of one off and 25% of making would be a legal ruling, but only if he judged MI to exist and those were the probabilities he attached to West finding the different lines of defence being found if given the correct explanation.

If the TD decides that it was more likely that there was MI than not, does he then have to give 100% of one off, assuming that he decides that it would always be beaten if the explanation was "probably checkback"?

[blackshoe]

barmar, on 2016-November-02, 15:43, said:

That's what I meant. I could have written "doesn't require conclusive evidence to rule otherwise". But since the law is already clear about which ruling requires evidence, I didn't think it was necessary to restate it here. The point I was trying to make was about what kind of evidence is required -- I was refuting whether the evidence needs to be "conclusive" on its own.

Ah. I misunderstood you then. Sorry about that.

[cherdano]

barmar, on 2016-November-02, 14:45, said:

Regarding the notation on the system card, I suspect most players who use checkback over 2NT use it when 2NT was a jump. I'm not sure I've heard of it being used after a 2/1 response, but maybe that's just my provincial experience.

It's very different when 2/1 is non-game forcing and 2NT did not show extras. If both 3D and 3H are non-forcing in this auction, then you are always more or less playing checkback ("making up a natural forcing 3C bid"), the only question is whether it is more checkback or less checkback, and whether you have discussed this explicitly.

If I had to guess, this partnership hasn't actually discussed this auction, and they have no explicit agreement.

[dburn]

"One can, I believe, give a weighted score based on the probability of MI"

I don't believe that. I believe that the Director must consider the "probability of MI" to be 1 or 0, depending on whether he thinks there has been any.

Of course, one can give a weighted score based on the probabilities of various events if the player had not been misinformed. Moreover, the Director might take the view that what he should have been told was "we have no agreement in this sequence but among possible meanings of the call are clubs and checkback." Armed with this, West might have returned a spade or he might not,

[minimonkey]

So it seems that:

1) A split ruling would not have been appropriate here - because either there was an infraction or there wasn't
2) The meaning of the word 'evidence' in 21B1B is pretty important. Whilst I have been told that 'rock solid' evidence would be needed at some tournaments to avoid the directors ruling against me (a philosophy which, from the TD's perspective, I'd imagine is attractive as it reduces the amount of case-by-case judgement involved and therefor accusations of favouritism) the term is not defined in the rules (or at least nobody has defined it yet) - so it is up for the director in the specific circumstance to define what counts as sufficient 'evidence' on a case by case basis and there is no right answer?

[phil_20686]

minimonkey, on 2016-November-03, 16:12, said:

So it seems that:

1) A split ruling would not have been appropriate here - because either there was an infraction or there wasn't
2) The meaning of the word 'evidence' in 21B1B is pretty important. Whilst I have been told that 'rock solid' evidence would be needed at some tournaments to avoid the directors ruling against me (a philosophy which, from the TD's perspective, I'd imagine is attractive as it reduces the amount of case-by-case judgement involved and therefor accusations of favouritism) the term is not defined in the rules (or at least nobody has defined it yet) - so it is up for the director in the specific circumstance to define what counts as sufficient 'evidence' on a case by case basis and there is no right answer?

A split ruling is appropriate if the director judges that there was MI but doesn't know what should/would/might happen next. A split ruling can never be based on the possibility of MI - either there was an infraction or there was not. In this case its not appropriate really as if there was mi and you were told 3C was CB you would have returned a spade.

PS:_Sorry_it_seems_my_spacebar_is_broken_today.....

Get your keyboard fixed. Blackshoe

This post has been edited by blackshoe: 2016-November-03, 20:55
Reason for edit: to replace underscores with spaces.

[gordontd]

A split ruling is not the same as a weighted ruling. A split score is when NS & EW are assigned different scores. A weighted score is when one or both pairs are given a percentage of the scores from more than one result. Split scores have in the past been given more commonly in the ACBL than elsewhere, using L12C1e, because until recently they didn't give weighted scores using L12C1c.

[paulg]

phil_20686, on 2016-November-03, 19:37, said:

PS:_Sorry_it_seems_my_spacebar_is_broken_today.....

Get your keyboard fixed. Blackshoe

I've had this issue a few times with the reply function in these forums, running on the beta channel of Chrome on Windows.

Phil's keyboard is not broken, he just doesn't read what he's published

[dburn]

minimonkey, on 2016-November-03, 16:12, said:

So it seems that:

1) A split ruling would not have been appropriate here - because either there was an infraction or there wasn't
2) The meaning of the word 'evidence' in 21B1B is pretty important. Whilst I have been told that 'rock solid' evidence would be needed at some tournaments to avoid the directors ruling against me (a philosophy which, from the TD's perspective, I'd imagine is attractive as it reduces the amount of case-by-case judgement involved and therefor accusations of favouritism) the term is not defined in the rules (or at least nobody has defined it yet) - so it is up for the director in the specific circumstance to define what counts as sufficient 'evidence' on a case by case basis and there is no right answer?

Whether or not there is a "right answer" is a matter of opinion.

jallerton and I (together with a latter-day Scottish Nationalist whose contributions were, as one might expect, wrong without being illuminating) spent some time in Brighton some years ago establishing a precedent for a "third way" resolution of this kind of problem. It has proved helpful in subsequent cases, and I have alluded to it above.

If there is no "rock-solid" evidence to establish whether there has been a misexplanation or a misbid - in other words, if there is doubt as to what the "correct explanation" is per the substantiated version of the partnership's agreed methods - then the "correct explanation" is deemed to be: "no agreement, but the range of possibilities is..." where the ellipsis includes what North thinks and what South thinks.

The non-offenders are deemed to have had that explanation, instead of the one they were actually given or instead of the one that the Director believes they should have been given.

In most hypothetical cases as in most real cases, the non-offenders then have to guess what to do: the score is adjusted in accordance with how well the referee thinks they would have guessed. They are given considerable "benefit of the doubt", but that is all: they are not allowed to know the opponents' hands, only the opponents' methods (including the extent to which the opponents don't know their own methods).