AndreSteff

The OP meant to make clear that the TD was called before South had led to the firs trick. I am sorry if this was not obvious. Apart from that I am interested if EW are likely to get any redress if West declined to change his last pass.

IMHO this is the crucial point of this case. So: should the TD apply Law 21B1, enabling West to change the pass to a call of 4♥? And if West declines to do so the score will (dependent on the outcome of the polls on South's lead and East's bidding) probably stand?

[hv=d=e&v=e&b=6&a=1cp1s2n3nppp]133|100|1C: best minor<br>2NT: alerted, explained by South as Hearts and Diamonds[/hv] Before South tables a lead, North explains that 2NT should have been explained as clubs and diamonds. East now calls for the TD. NS do not agree on the meaning of the 2 NT overcall. 1. How do you proceed? [hv=pc=n&s=sa62ht543dajt6ct2]133|100[/hv] 2. Let's assume that the contract stays at 3NT. South leads the Jack of Diamonds. Do you think that this lead can be accepted as logical alternative that was not suggested by the UI? Full hand below.... [hv=pc=n&s=sa62ht543dajt8ct2&w=skqj873hkj762dk4c&n=s5h8d97653ca87654&e=st94haq9dq2ckqj93&d=e&v=e&b=6&a=1cp1s2n3nppp]399|300|1K: Best minor<br>2NT alerted and explained by South as Hearts and Diamonds.[/hv] 3NT on a diamond lead met an unhappy fate. East objects: had he known that North had the minors he would not have bid 3NT. 3. Assuming that East's remark is relevant, do you expect a poll to confirm his assertion?

The ruling There are two questions to answer: Has an action been taken based on the unauthorized information while there was a logical alternative? Was there damage due to misinformation? In the Netherlands there is a common understanding among TD's that when partner passed at his turn to open the player that has received UI may from this draw the conclusion that partner will not have a long suit of his own. But does a five card clubs qualify for a rebid at the five level without adjustment in this case? (Apart from that Bridge players in NL convince one an other that you may always run from UI when you have a singleton in partner's suit). Well, in the poll of 6 players two players did pass 4♠, simply because they were not convinced that bidding 5♣ would lead to a better result. These players took partner's pass at his turn to open the hand into account in their decision (and they were of course not told of the UI). So, the result was adjusted to 4♠-5. There remained the question of whether playing the Ace of Diamonds in trick one should be considered a serious error. The polled players all would have ducked the opening lead, but it took them a considerable time to come to the conclusion that after this auction too that was the best action. Had South been able to show the majors over a natural 2♣ call from East they judged that the decision to duck the ace of diamonds would have been easier. The TD judged that playing the Ace of Diamonds was no serious error and that the damage caused by it was related to misinformation. So, no split score was assigned. This was all explained to East in much detail and he seemed to understand and accept this. This is the question that remains: Should the TD indeed rule that there has been misinformation? Doing otherwise feels quite wrong for me. The pair did agree to play Ghestem and their convention card confirms this. But it was their first time playing together. East stated that he was of the opinion that after a Dutch doubleton Ghestem did not apply.

About being the alert on 2♣ being misinformation: The Dutch regulations currently make it crystal clear that the TD should rule misinformation. But can a TD from any other jurisdiction really rule otherwise for a first time partnership that has system cards that admittedly read "Ghestem"? East explained that he thought they had agreed not to play Ghestem over a Dutch doubleton.

Until now nobody has addresssed North's claim that he would have been more likely NOT to play the Ace of Diamonds in trick one if South could have made a call over a natural 2♣ bid showing the majors.

"The defacto agreement "either majors or clubs" is a BSC but I am not sure if Dutch TDs see it that way. And if BSCs are allowed as defense against a 2+ clubs (i.e. is the 1♣ opening considered artificial for that purpose?)." It certainly would be considered a BSC in the Netherlands. Up to 2015 BSC's were allowed after Dutch doubletons, but this was changed. However, in ruling these kind of cases the de facto use of a BCS in the context of bidding misunderstandings is not taken into account.

[hv=pc=n&s=sqjt4hkt763djtc84&w=s8532h5dk864cq763&n=sk976haqj2da93ct5&e=sah984dq752cakj92&d=s&v=n&b=15&a=pp1c(Alerted%3A%20dutch%20doubleton)2c(Alerted%20for%20the%20mayors%20by%20West)p4sp5cppdppp]399|300[/hv] 1:♣: Dutch doubleton (1♦=4+, 5 card major.) 2♣: Alerted by West, asked by South. West explains: we agreed on playing Ghestem, so he promises the majors. But well, this is the first time we are playing together, so... Lead: Jack of diamonds, low in dummy, trick won by the ace. Result: 5♣ doubled and made. North is not amused: he has serious doubts that the 5♣ bid is allowed and he states that if South would have known the clubs were real he could have doubled 2♣ to show the majors. This would reduce the chance of East having a singleton Queen of diamonds, so he would have been less likely to play the Ace in trick one. Of course, the answer to what the TD should rule is heavily dependant on the results of his polling other players. NS are very strong players , West is a strong player, East is a 16 year old beginner with a lot of promise... I will post the result of the polls later. So: how should the TD rule? Fill in your own idea of what the polls are likely to show.

South is declarer in a hearts contract. West leads a diamond, low in dummy, East ruffs, but is revoking. South does not notice the revoke and ruffs himself (no revoke) with a lower trump. He therefor has not won the trick, but thinking he has he leads out of turn to the following trick. Before West has followed suit East wakes up and shows a diamond. How should the TD handle this?

Sorry, I do not think that is funny. Of course the question is: how should the TD handle this? I am no native speaker.

This case must have been discussed before, but I cannot find it. I apologize for the duplication. North deals, but South starts the auction with "Pass". West protests on which South takes back the pass and North opens 2♠before EW get the chance to express their wish to see the TD. How to handle this one?

South was the more experienced player of the two, He prefers and usually plays "1430" himself, but knew that his partner, with whom he plays irregularly, plays "40". There was no explicit agreement made for this event, but South realized that he should have adopted his partner's preference, as his partner certainly would not have adopted South's preferred answering scheme. So, in a way there was a common sense agreement that 5 clubs showed zero or four aces. As I stated, under dutch regulations the TD should now rule misinformation. What interests me is the fact that not covering the Queen cannot win: even as partner has a singleton ace of clubs, he is going to be endplayed.

Well put, but that does not answer the questions in the OP.

[hv=pc=n&s=saqj97h76d2cjt742&w=s654ha92dk964ca98&n=s2hqt54daqjt73ck5&e=skt83hkj83d85cq63&d=e&v=0&b=14&a=p2sp3dp4spp]399|300[/hv] 2♠is "Muiderberg" : 5 card major with at least a 4 card minor. 3♦ was alerted by South. Usually it is an inviting bid for 4♠. 2♠ and 3♦ were duly alerted, but no questions were asked as EW thought to know what was going on. However, when West tabled his face down lead, North corrects that 3♦ should not have been alerted. East now claims his right to change his last pass and persists after an explanation that he is just entitled to the right information, not to the misunderstanding. The TD allows East to change his last call, who now doubles. North corrects to 5♦, doubled by West. In the end NS have just exchanged one bottom score for another as 4♠ undoubled down two was the worst possible score for NS in this field. But just out of interest: Stands East's correction of his last pass to double? Is North allowed to change to 5 ♦?

[hv=pc=n&s=st985hktdjt4cat54&w=s72hq9732dq87cj73&n=sakq3ha4dak632cq6&e=sj64hj865d95ck982&d=w&v=n&b=12&a=p1dp1sp4np5cp5sppp]399|300[/hv] When West tables his lead face down, East asks North how many aces the 5 clubs answer on Blackwoord promised. The answer was "zero". As playing the "1430" pattern is now nearly ubiquitous in the Netherlands, East asks South if the 5 clubs answer indeed promises zero or four aces, rather than one or four. South confirms that he has promised zero aces. Lead is a heart, won in dummy. Declarer plays three rounds of trumps, crosses to his hand in hearts, succesfully finesses in diamonds and runs them. Finally the queen of clubs is led from dummy. East, fearing that partner's ace of clubs may now be single, plays low. Result 5 spades +2. Of course EW are not amused. The setting is a pub drive, late in the afternoon, by which time the level of inebriation of the participants tends to be considerable. Both NS and EW play occasionally together. NS do not have a convention card. Under dutch regulation this is enough to rule misinformation. NS are subaverage, experienced players, EW are very strong players, one of them an international. South excuses himself profusely, he was just too tired and intimidated to answer correctly. He was not sure what the agreemnt over Blackwood was. So, how shoulld the TD rule?