Undiscussed, but I can guess how partner will take it
Sometimes a bidding sequence that's completely unprecedented comes up. Often, though, there are similar relevant agreements (or just bridge logic) that give me a good idea of how my partner will react, and it seems important to explain these to the opponents.
To give some context, here's a recent example: (1NT), 2!s!, (P), 4!h?
1NT was 12-14. The 2!s bid is natural, but very wide-ranging (by partnership agreement, anywhere from 6 to 15 points, and 5 spades are enough although we could well have more). As a consequence, we alert it (natural, but an unexpected meaning for many players).
The partnership agreement for the advance of 2!s is that raising spades is acceptable with length, but otherwise to pass with almost any hand. The 4!h was therefore undiscussed and somewhat anti-systemic.
I was the 4!h bidder, and self-alerted (BBO alert box, so limited space) as "undiscussed, probably natural". At least looking at the bidding in the abstract, I don't think there's an obvious reason that 4!h necessarily would be natural, but I know that a) over an opening 2!s weak, 4!h would be natural, and the 2!s overcall isn't all that different from a weak two; b) we have a general agreement not to interpret undiscussed bids as splinters; c) it's certainly possible for me to hold hearts given the bids so far, and my partner tends to interpret undiscussed bids as natural if they could plausibly be natural.
My opponents were quite upset, though; they said that I shouldn't be speculating on how partner will take an undiscussed bid. (After all, if we weren't self-alerting, but were instead alerting each others' bids as in person, it wouldn't be correct to tell partner how we were taking the bid in the "undiscussed" alert.)
Who was right here? In particular, should "undiscussed" self-alerts attempt to summarize the relevant agreements? (Should I be alerting undiscussed calls at all? I think I probably should be; there's no real harm in over-alerting online and our partnership is not 100% reliable at understanding each other's undiscussed calls, so the alert is required in case partner interprets the call with a meaning that would be alertable.)
Comments
I'm puzzled by two things you say. What aspect of your 2S bid might be unexpected? Why would 4H not be assumed to be natural in the absence of any contrary agreement?
The part of the law about alerting unexpected meanings is very ambiguous to me. Whilst a 2S overcall of 1NT meaning 6-15 points is not unexpected to me, I can understand this being unexpected to less experienced players. So the alert may be applicable to some players, but not others?
Similarly, it is possible that 4H could be taken as a splinter to cue bid, particularly where these are played in some circumstances and this situation is undiscussed. I personally like the alert of "undiscussed, probably natural" as this is very similar to alerts that I do when I play with one of my partners as the partnership is new and we are working through things. In the spirit of full disclosure I want to let the opponents know that this bidding sequence is undiscussed, though we have agreements in similar situations. On occasion I have completed a similar self-alert, then quickly messaged the ops (on BBO) with a more complete description, for example, 'could be a splinter or natural'.
When playing at a club level, I've been told by the Director in charge that night that most of the my opponents would be expecting the overcall to be stronger than 6 (and some players might not expect the high end of the range to be quite so strong, given how weak the low end is). So I've been alerting it because the range is unexpected for most of the players I play against in clubs (and elsewhere because I can't be sure of the standard of the opponents). I guess this comes down to the old problem of the "alert natural bids if they're unexpected" rule relying on a lot of knowledge as to what your typical opponents will expect!
4!h could at least plausibly be interpreted as a splinter (probably not in our partnership), or as hearts + spades (i.e. "raise with length, but trying to get in some extra information to help the defence, or help partner to judge whether to bid onwards, if the opponents compete"). And it's much easier to alert an undiscussed bid (especially as you have to alert straight away) than it is to think through all the possibilities and try to work out whether or not there is in fact only one plausible meaning (given that responder passed, hearts + spades probably isn't a useful meaning, but I only just realised this and thus wouldn't have been able to work it out at the table).
I agree that opponents are entitled to the "undiscussed" part of the alert but I'm not fond of the addition of "probably natural". On the other hand, you do have an agreement that it's not a splinter, so the hearts are real. I guess the true point is that you aren't promising spades, therefore the bid must be natural and "to play". Maybe tell them it's not a splinter and let them work out what they care to ask.
I think my real issue the use of the word "probably". I find that rarely to be a good word in a description of a bid. I'd prefer to know what it is or what it isn't not what it might be interpreted as.