[AL78]

This hand is about counting opener's distribution by cashing diamonds after drawing trumps to deduce their minor suit length. The instructive point is that when East (after opening 2♥ and showing up with three spades) discards a heart on the third round of diamonds, their distribution is 3622. Dummy holds ♣KTx and declarer holds ♣Axx, so when declarer cashes the ace and a club honor falls from opener on the right, they are to deduce that they hold QJ doubleton and the correct play is to cash the king, felling the second missing honor card, promoting the ten to the tenth trick. My question is, if RHO is a world class player, could they possibly drop the jack or queen from Hx which would guide declarer into the losing line if they played as BridgeMaster advocates?

[Cyberyeti]

Declarer is simply going off if they hang on to the honour so no

[johnu]

AL78, on 2021-September-14, 12:48, said:

My question is, if RHO is a world class player, could they possibly drop the jack or queen from Hx which would guide declarer into the losing line if they played as BridgeMaster advocates?

Playing an honor from Qx or Jx would be an example of a Grosvenor Gambit/Coup.

Grosvenor gambit

[AL78]

johnu, on 2021-September-14, 14:40, said:

Playing an honor from Qx or Jx would be an example of a Grosvenor Gambit/Coup.

Grosvenor gambit

Someone once pulled that coup against me. I had ♥AKJTxx in dummy with no side entries, ♥xx in hand, I was in a spade contract. I took the finesse which held, came back to hand, and took the finesse again, which lost. RHO had ducked holding ♥Qxx. Suckered!!

[AL78]

Cyberyeti, on 2021-September-14, 13:43, said:

Declarer is simply going off if they hang on to the honour so no

Yes, good point.

[smerriman]

AL78, on 2021-September-14, 14:51, said:

Someone once pulled that coup against me. I had ♥AKJTxx in dummy with no side entries, ♥xx in hand, I was in a spade contract. I took the finesse which held, came back to hand, and took the finesse again, which lost. RHO had ducked holding ♥Qxx. Suckered!!

That's not a Grosvenor - ducking with the queen is often a good play in that situation.

[Cyberyeti]

AL78, on 2021-September-14, 14:51, said:

Someone once pulled that coup against me. I had ♥AKJTxx in dummy with no side entries, ♥xx in hand, I was in a spade contract. I took the finesse which held, came back to hand, and took the finesse again, which lost. RHO had ducked holding ♥Qxx. Suckered!!

I fell foul of a funnier version of that, I ducked Kx over AQJ to a number in dummy, then discovered declarer didn't have the hand she bid and didn't have any way back to hand and so had to try to drop the K

[AL78]

smerriman, on 2021-September-14, 15:13, said:

That's not a Grosvenor - ducking with the queen is often a good play in that situation.

I asked her why she ducked and she couldn't answer, so I don't think they were of a standard where they are familiar with plays like that.

[AL78]

Cyberyeti, on 2021-September-14, 15:49, said:

I fell foul of a funnier version of that, I ducked Kx over AQJ to a number in dummy, then discovered declarer didn't have the hand she bid and didn't have any way back to hand and so had to try to drop the K

Oops, what did your partner have to say about it?

[sfi]

Cyberyeti, on 2021-September-14, 15:49, said:

I fell foul of a funnier version of that, I ducked Kx over AQJ to a number in dummy, then discovered declarer didn't have the hand she bid and didn't have any way back to hand and so had to try to drop the K

That's the sort of thing we all do once. You only need to start worrying if you do it again.