[jallerton]

Law 21B3 says:

Quote

3. When it is too late to change a call and the Director judges that the offending side gained an advantage from the irregularity he awards an adjusted score.

Law 40B6 says:

Quote

6. (a) When explaining the significance of partner’s call or play in reply to opponent’s enquiry (see Law 20) a player shall disclose all special information conveyed to him through partnership agreement or partnership experience but he need not disclose inferences drawn from his knowledge and experience of matters generally known to bridge players.

(b) The Director adjusts the scores if information not given in an explanation is crucial for opponent’s choice of action and opponent is thereby damaged.

Suppose that South gives a reasonable, but slightly incomplete, explanation of his methods (for example, they have no agreement about the actual sequence, but South fails to mention an analogous agreement which could be relevant). The omitted information was not crucial, but East's thought process might have been different had the explanation been more complete. Law 21B3 suggests that the TD should award an adjusted score, but Law 40B6(b) seems to suggest no adjustment. Which takes precedence?

[pran]

 jallerton, on 2014-May-17, 02:07, said:

[...]
Suppose that South gives a reasonable, but slightly incomplete, explanation of his methods (for example, they have no agreement about the actual sequence, but South fails to mention an analogous agreement which could be relevant). The omitted information was not crucial, but East's thought process might have been different had the explanation been more complete. Law 21B3 suggests that the TD should award an adjusted score, but Law 40B6(b) seems to suggest no adjustment. Which takes precedence?

Why do you say it was not crucial if it affected East's thought process into selecting an unfortunate and damaging (to his own side) alternative?

You are contradicting yourself.

[jallerton]

In practice, players take into account many factors, including explanations received from opponents, when selecting a call.

"Crucial" in Law 40B6b implies to me that we only adjust if the MI was the main reason why the player took the unsuccesful action at the table; so if we judge that the player should have selected the successful action anyway then we shouldn't adjust the score.

On the other hand, Law 21B3 implies to me a different approach. We completely ignore what the player did at the table and just make an independent assessment as to what the player (or his peers) might have done given correct information.

[pran]

My Oxford says Crucial: Very important, decisive
My Webster says: Crucial: Decisive, critical.

Now if a player has not yet completely made up his mind but does so when receiving MI then to me that implies that this MI was "crucial".

And of course if he had made up his mind but changed it when receiving MI then there can be no doubt that this MI was indeed "crucial".

The important exception in both cases is of course when the director finds that the player apparently tried a double shot.

[blackshoe]

Provided you define "double shot" as "I don't know if this is the right action, but I'll take it anyway, and if it doesn't work out I'll ask the director to bail me out".

[pran]

 blackshoe, on 2014-May-17, 13:25, said:

Provided you define "double shot" as "I don't know if this is the right action, but I'll take it anyway, and if it doesn't work out I'll ask the director to bail me out".

That is precisely what we call "double shots" as Norwegian TDs. (And we are specifically trained to be vigilant and not take over the playing from the players.)

[campboy]

 jallerton, on 2014-May-17, 02:07, said:

Suppose that South gives a reasonable, but slightly incomplete, explanation of his methods (for example, they have no agreement about the actual sequence, but South fails to mention an analogous agreement which could be relevant). The omitted information was not crucial, but East's thought process might have been different had the explanation been more complete. Law 21B3 suggests that the TD should award an adjusted score, but Law 40B6(b) seems to suggest no adjustment. Which takes precedence?

I think we use 21B when the explanation is incorrect (including a failure to alert), and 40B when it is merely incomplete. I think this is consistent with 20F4

Quote

If a player subsequently realizes that his own explanation was erroneous or incomplete he must call the Director immediately. The Director applies Law 21B or Law 40B4.

which suggests to me that whether the TD applies 21B or 40B depends on whether it was erroneous or incomplete (though if that is what is meant it would have been clearer to add the word "respectively").

[pran]

 campboy, on 2014-May-18, 01:45, said:

I think we use 21B when the explanation is incorrect (including a failure to alert), and 40B when it is merely incomplete. I think this is consistent with 20F4

which suggests to me that whether the TD applies 21B or 40B depends on whether it was erroneous or incomplete (though if that is what is meant it would have been clearer to add the word "respectively").

There may be a technical difference, but I honestly fail to see that there is any practical difference.

TD will first establish that there has been MI (erroneous or incomplete doesn't really matter)

If the MI has been discovered in time for a player on the non-offending side to withdraw his call then TD will apply Law 21B1a.

Otherwise TD will judge whether as a result of the MI a non-offending side has been damaged and in case award an adjusted score. He may refer to Law 21B3, Law 41B6 or both, the result will be the same.

(Note that Law 40 primarily concerns the use of special partnership understandings and damage from the use of illegal agreements while Law 21 is the general Law on misinformation.)