campboy

That's the ACBL regulation, I assume. FWIW the EBU bidding box regulation deals with this differently:

The relevant law for the first question is 81C3, talking about the TD's duties: I don't think that covers this case, but it's not completely clear and there's no specific guidance in the White Book. There was no irregularity, provided declarer did not realise his mistake, and "error" IMO means things like entering the agreed score incorrectly, not mistakes like this. As for the second part, defenders can withdraw their agreement (Law 69B) provided they are within the correction period (normally 30 minutes after the score has been made available for inspection).

Splintering with two small would also be a psyche, but rebidding a 3-card suit (where the agreement is 4+) or opening a 5-card major with four would likely be a deviation IMO. I agree with Trinidad's view.

I don't think "concession at trick 13" is a thing. Even if it is possible to concede at this point, I think the onus is on the defender to make it clear that it is a concession, not a play. I would rule that the ♣Q has been led.

25% for each suit looks like a Reverley ruling (so not legal) to me. If the comment suggests leading a spade over some logical alternative, no proportion of a spade lead can be given; if it doesn't, we shouldn't adjust at all.

I hope you wouldn't question the morality of me saying I have Star Wars on DVD. (In fact I have something that's since been mucked about with by George Lucas, and not the original version in which [spoiler redacted] shot [spoiler redacted].)

Of course there is intent to deceive. You want to deceive them into thinking you like it. You have a reason for trying to deceive them, but that is the case with almost any lie; it's not particularly relevant what that reason is. FWIW the (British) dictionary I have to hand is Collins, which says

I can give you more if you want. As I said upthread, this isn't a simulation; it's an exact calculation. [edit] The precise value, for anyone who may be interested, is 14574888024790152694633 / 24852706986690307830040. Unless there's a mistake in my program, of course.

We have to work with the definition that is actually in the laws, not the one that we would like to be there. I agree that your definition would be a great improvement.

You could, but by that argument it would be impossible to lead out of turn in any situation.

I think pran is right. The laws define "lead" as "the first card played to a trick". No other card has been played to this trick. So the play out of turn (and we all seem to agree it was played) was a lead, even though the player did not intend it to be. I don't like it, but that is what the laws say.

West is right about the implications of UI IMO; if he had pulled the redouble and gained, then I would be adjusting. I don't see why North would do anything differently if told "undiscussed", since East presumably has no idea what it might be other than penalty. If East is aware of what West usually plays with [edit: the other] South, that would be a different matter of course. It was the Earl of Yarborough, but I shall try to get out more.

Thanks for posting the full tables. In that case, whatever the figure after the +/- in the summary table posted upthread are supposed to be, they are not the standard deviations (or the variances). The standard deviation for 24 total trumps, based on Ginsberg's frequencies, is 1.113 -- almost identical to the result of my sim (and the variance -- the square of the standard deviation -- is 1.240). The actual standard deviations arising from Ginsberg's table are as follows. 14 15 16 17 18 19 20 21 22 23 24 0.898 0.912 0.986 1.034 1.118 1.145 1.188 1.216 1.240 1.148 1.113

Analytically.

FWIW the correlation coefficient is 0.58645 by my calculations.

Thanks. The answer to Helene's question is "yes", then.

Good question. Where there are two fits of the same length my script uses the higher-ranking suit, so essentially picks one at random. It does assume that contracts are right-sided, where relevant. [edit] Based on the mean, it seems Ginsberg is also right-siding the contract but either picking the suit at random or averaging the two suits where there is a double fit. For 14 total trumps (where there is always a double fit), on a sample of 1000 (different to the previous sample but the same one for each calculation) I got the following means: average over both suit and declarer 13.763 average over suits of better declarer 13.848 better suit and better declarer 14.426 better suit; average of declarers 14.341 (Ginsberg's mean 13.85) The mean alone can't tell me whether he is averaging for the two suits or picking a random one; the fact that his standard deviation is lower suggests the former, but making that change would only push the standard deviations in my previous post down, and the most striking difference is that the deviations for the higher numbers are already much lower than his. I also think picking a random suit is a better way to estimate the standard deviation, since that is more like what happens at the table (whereas I expect contracts are right-sided most of the time in practice).

It would, if that is what he means by "x±y" and the figures are accurate. But I tried doing the same thing (with Thomas Andrews' Deal program), and got completely different values for the sample standard deviation. I used 1000 samples for each number of total trumps; I'll try again with bigger samples if I have time. trumps sample mean sample s.d. 14 13.82 0.866 15 14.873 0.909 16 16.113 1.010 17 17.032 0.999 18 17.947 1.095 19 18.783 1.131 20 19.55 1.186 21 20.138 1.208 22 20.679 1.192 23 21.192 1.195 24 21.675 1.111

Ah ok. It just didn't occur to me that the second number was supposed to be the standard deviation, because the way it is written with +/- makes it sound like a confidence interval. But of course the actual numbers are much more consistent with it the former interpretation.

It's not clear to me how he's calculated these numbers. Assuming the ± bit gives a confidence interval for the expected number of tricks, the greater uncertainty for the 21+ range would just be a consequence of the low sample size; it doesn't mean there is a higher variance in the number of tricks made. However, the actual numbers given make this interpretation a bit implausible.

On the contrary, I think we should expect more convincing proof in this case than for a medical study. It should be trivial to get huge amounts of data on the LoTT, just running random hands through a double-dummy analyser. Even with the resources of a massive multinational company, you just can't do medical trials on enough people to compete.

I have heard it said that "one card at a time" means that consecutive cards should not be dealt to the same pile, though there doesn't seem to be anything official to support that interpretation. Presumably, though, it means something. (edited to clarify which post I was replying to)

No, Law 54A says: [edit] Actually I now see that OP doesn't actually say West led face up; if the lead was face down, ignore me.

I can see that this would be a reasonable interpretation of the law, but it is not the interpretation which is generally accepted as correct. In fact, looking in the White Book I discovered there is a minute about it, albeit one which was written for a previous version of the laws.

Well, that's a funny way of looking at it, since the thing that tells us to adjust the score is one of that "bunch of rules". But yes, the lawmakers, rightly or wrongly, favour laws which give OS some chance of getting a normal result, but sometimes require the TD to step in and restore equity.