Law 21B1b
Law 21B1b The Director is to presume Mistaken Explanation rather than Mistaken Call in the absence of evidence to the contrary.
To my mind, this is is most often applied when two players in a partnership have different understandings as to what a bid means in their system. Rather than having to pick one, the director takes the view most favourable to the opponents and rules misinformation.
Now suppose you have a pair that both claim to play long suit trial bids. For various reasons, one player chooses to make such a bid without a long suit - not as a psyche or with a deliberate intention to mislead, but because the response from his partner will tell him what he needs to know.
Opponents complain when they mis-defend as a result of assuming the player has a long suit.
The pair's convention card makes no mention of trial bids.
Both players are adamant that the bid shows a long suit, and there has been no fielding of the bid in question.
WB 8.21.4: The laws do not require a TD to automatically rule misinformation rather than misbid in cases where there is no documentary evidence one way or the other.
Having spoken to both players, I am happy that they were probably playing long suit trial bids.
Do I need more evidence that my "balance of probabilites" feeling?
Comments
It would seem that the trial bids are asking bids. If they can make the bid on 2 of fewer cards, because the response tells them what they needs to know, they should be alerted. They should be explained as "ostensibly a long-suit trial bid, but could be any length is the response tells them what they needs to know,"
If they agree that something like that is their understanding, then rule on the basis that that was what the opponents were entitled to be told.
Otherwise the opponents are entitled to "we don't have a common understanding: either a long suit trial bid with length OR not showing length, just interested in the responses (to 'a long suit trial bid')"
"To my mind, this is is most often applied when two players in a partnership have different understandings as to what a bid means in their system. Rather than having to pick one, the director takes the view most favourable to the opponents and rules misinformation."
I don't think that is our usual approach in the EBU: we either decide that one of them is the true meaning or we rule on the basis of "we don't have a clear agreement but either of these are possible", together with any other relevant agreements we can establish.