[RMB1]

Vampyr, on 2011-December-10, 06:12, said:

So they would cheat and then decide to tell on themselves? Seems kind of unlikely.

It is quite possible to have implicit understanding based on previous actions and only identify that one has such an understanding when the situation arises and you are asked about it. These understandings have been concealed, but this is not deliberate and is a long way from cheating.

[bluejak]

Cheating? Who said anything about cheating?

Lots of players do things wrong and own up when asked.

[nigel_k]

There are two possible grounds for adjustment:

1. Call taking advantage of unauthorised information
2. Call made based on a concealed partnership understanding

Re 1, let's assume there was a BIT and therefore UI that advancer was thinking about something. In order to determine whether the UI suggests passing, we have to compare the probability that advancer will just have hearts when he breaks tempo with the probability that advancer will just have hearts when he bids 3♥ quickly or in normal tempo. Based on my experience the latter probability is higher so the UI does not suggest passing.

Ground 2 is the 'fielding' scenario. In general, if there is a psyche or other situation where a player deliberately departs from his partnership agreements in order to deceive opponents then the cost/benefit of doing this is greatly improved if partner has seen it before and knows not to rely on your actions but doesn't share this knowledge with the opponents. But the key reason that this is regarded as a serious breach of the laws is that it is hard to detect.

The example in the OP is different in that it is very easy to detect. At worst there is a concealed understanding that 2♥ followed by 3♥ cancels the message about spades and is a signoff. Probably this is not actually the case here, but it is something the director will have to determine by asking the right questions. Even so, the other side can call the director if they were damaged, e.g. because they were prevented from bidding spades.

More likely the concealed agreement, if there is one at all, is much more ambiguous than that and requires the 1NT bidder to guess whether advancer has spades by looking at his own hand. Obviously that is not an agreement anyone would choose voluntarily, it has been forced on them by their own poor memory. In that case, I suppose the director might choose to impose a penalty for the failure to disclose the agreement, but the opponents should not expect to gain from an adjustment unless they were actually disadvantaged by not being aware of the undisclosed information.