How much should you tell opponents about your methods?

As much as you can.

Imagine they were present when you and partner discussed your system – they are entitled to know all your agreements and any inferences you can draw from partnership experience.

Please make an effort to be as helpful as possible.

What opponents are not entitled to know is which cards you actually hold.

Say partner leads a king against a suit contract. Declarer asks about your carding. State your agreements – perhaps "could be from AK or KQ, asks for a count signal".

If you know from your own hand that they have actually led from Kx – dummy has AJx and you are looking at Q109x – you should not make any extra comment.

Everybody knows that Kx is a possibility: by mentioning it you may give Unauthorised Information to partner.

Describe your agreements, not what you know from your own hand.

If you are unsure of the meaning of partner's bid – admit that.

‘Undiscussed' may be true, but if you have an inkling based on partner's actions in similar situations you should say so.

What you must not do is say ‘ I am taking it as….'

That is Unauthorised Information. As a corollary, an opponent may not ask : ‘What do you take it as?'

Please Ask Nicely!

Many players are intimidated by aggressive questioning. Inexperienced players are particularly vulnerable: they may not understand the question or know what kind of answer is expected.

You are entitled to know opponents' partnership agreements:
"During the auction and before the final call, any played may request, at his own turn to call, an explanation of the opponents' auction. He is entitled to know about calls actually made, about relevant alternative calls available that were not made, and about inferences from the
choice of action where there are matters of partnership understanding.

After the final pass and throughout the play period, either defender at his own turn to play may request an explanation of the opposing auction. At his turn to play from his hand or from dummy, declarer may request an explanation of a defender's call or card play understandings."

DO Remain polite at all times.

Law 20F: Explanation of calls

Such questions are answered by the partner of the player who made the call or play, as fully and helpfully as possible. What is important is the manner in which the question is posed:

Do NOT

  • Adopt a ‘Bad Cop' line of questioning.
  • Put words into opponent's mouth: “Is that Drury?”
  • Repeat the same question in a louder voice.
  • Insist on an explanation when told ‘we have no agreement'.
  • Ask ‘what are you taking this as?'
    If your opponent genuinely does not know what a bid means bullying will not help!

DO

  • Remain polite at all times
  • Ask clearly: if your original question is met with a blank expression try to clarify.
  • Make sure you have fully understood the reply to your question: follow up if necessary.
  • Be Nice!