[pilun]

Okay, declarer is in 7♥ and has to lose to the ♠A

When he leads towards dummy's ♠KQ, East - sitting over dummy with ♠AJ9 is about to take the setting trick.
Declarer calls for a spade honour.

Case 1. East drops the ♠9 on the table.

Case 2. East drops the ♠J on the table.

Say this is on BBO with [UNDOs] allowed for "genuine mis-clicks" in this particular event.

Case 1a. East mis-clicks the ♠9.

Case 1b. East mis-clicks the ♠J.

[pran]

pilun, on 2021-July-13, 03:51, said:

Okay, declarer is in 7♥ and has to lose to the ♠A

When he leads towards dummy's ♠KQ, East - sitting over dummy with ♠AJ9 is about to take the setting trick.
Declarer calls for a spade honour.

Case 1. East drops the ♠9 on the table.

Case 2. East drops the ♠J on the table.

Say this is on BBO with [UNDOs] allowed for "genuine mis-clicks" in this particular event.

Case 1a. East mis-clicks the ♠9.

Case 1b. East mis-clicks the ♠J.

I will leave BBO out of this discussion because they have their own regulations.

Now Laws 49 and the relevant parts of 50 are pretty clear and we have:

If the card dropped by East was the ♠9 it is a minor penalty card, and he is allowed to cash his ♠A when declarer plays his ♠Q from dummy. (Law 50C)

But if the card dropped by East was the ♠J he must play this major penalty card at the first legal opportunity, i.e. under the ♠Q . (Law 50D1a)

[mycroft]

At the table:
1: minor pc, east can play the A, 7♥-1, Law 50B, C.
2: Major PC: east plays the J, 7♥=, Law 50B, D1a.

BBO "genuine mis-clicks":
all cases, it should be obvious that this was a misclick, 7♥-1.

Now, different BBO rules:
"ACBL Regionals": follow, as best they can, the Laws. It would map to "at the table", above.
"obvious undos during the bidding, not in the play": 7♥= both cards.
"no undos": again 7♥=. Set confirm if you can't deal with the odd mistake.

Please note, at the table: I don't want to be asked about revokes, as declarer or defenders. It distracts me enough to drop more tricks than the one or two revokes a year that get past me. I don't ask as defender; I will ask as dummy if partner wants (but prefer not). When it happens, I don't complain about it, I pay for my mistake (*). Similarly, I don't put "confirm" on for bids or plays on BBO; the frustration and distraction (and I'm a system administrator, "finger memory confirm" is a thing) would cost me more than the two or three misclicks I make a year (**). But, and this is critical, this is *my* decision; I can't and won't insist anyone else do it my way.

*: Further on with revokes: I call all revokes I notice from my side, even if I'm the only one that noticed it, even if it didn't cost a trick. I pay the penalty freely, and if my partner doesn't like it, he can play with someone else. That's because I am a director, and I will enforce revoke (and MPC) penalties on the opponents, even if it wouldn't cost a trick, and anything less really would be "bridge lawyering". Again, beyond requirements, and I can't and won't insist on this from anyone else.
**: although I'd really like a "are you sure" flag when it goes [#]-explanation-Pass (even [#]-Pass). But that's not worth turning on "double click instead of single click to bid, which in two weeks is going to be finger memory".

[pilun]

pran, on 2021-July-13, 09:35, said:

I will leave BBO out of this discussion because they have their own regulations.

Okay. I will post there. Problem of course is that different countries have different advice on UNDOs, perhaps varying according to the grade of the event. And of course, BBO is not a country.

I have never been happy with "UNDOs only for mis-clicks in the AUCTION".
That could lead to players choosing [Confirm] for cards but not for bids. As Mycroft points out below, double-clicking to play a card quickly becomes a cerebellum activity, particular if you have to do it 26 times as declarer.

some card mis-clicks are "genuine" but many are problematic, from failing to comprehend who played what.
Like a player sitting over A-Q with KJ - expecting a finesse - then "mis-clicking" by dropping the king under dummy's ace.
Would be good to have guidelines.

[blackshoe]

BBO is not a Regulating Authority.

[pescetom]

blackshoe, on 2021-July-14, 09:59, said:

BBO is not a Regulating Authority.

But it has spawned (out of necessity) a series of regulations from various RAs and non-RA organizers.
As has Realbridge with its analogous but different mechanisms.
Currently there are no effective WBF laws for online play, nor do they even seem likely.

[blackshoe]

Does BBO actually specify any regulations?

[barmar]

blackshoe, on 2021-July-14, 09:59, said:

BBO is not a Regulating Authority.

BBO is the equivalent of the club in the case of ACBL speedballs and individuals.

Undos aren't allowed, so the issue in this thread doesn't come up. Otherwise, they mostly follow ACBL f2f tournament regulations, except that 15-17 1NT doesn't have to be announced.