[jillybean]

Here is one totally flat board. 4♠ (14 tables) or 5♠ (3 tables), bid by East, all making 6 for +480

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After the hand, Declarer mentioned if there had been 4 trump out, this was a restricted choice play "8 or 9 married to the Queen"
Can someone please explain this?

[mikeh]

jillybean, on 2024-November-09, 22:44, said:

Here is one totally flat board. 4♠ (14 tables) or 5♠ (3 tables), bid by East, all making 6 for +480

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After the hand, Declarer mentioned if there had been 4 trump out, this was a restricted choice play "8 or 9 married to the Queen"
Can someone please explain this?

The simple explanation is that declarer has no clue about the game

There was a ‘theory’ many years ago that said that the queen usually lies over the jack. There was actually some evidence that this was slightly more likely than not…..back in the glory days of rubber bridge…which was by far the dominant form of the game in the early decades, though almost non-existent today. When one played to a trick, the card was placed in the middle of the table….all four cards were piled together and whichever side won the trick stacked those cards in a 4 card pile. Somif a finesse of the jack lost to the queen, those two cards were usually immediately adjacent in the trick pile. Insufficient shuffling…shuffling east into playing time…would tend to keep adjacent cards together more often than is desirable…so the queen would tend, slightly, to be dealt right after the Jack.

However, there’s no logic nor merit to the 8 or 9 is married to the queen. Either he/she was joking or simply talking nonsense.

And the remark about restricted choice tends to reinforce the probability that the speaker is a fool. Restricted choice has nothing to do with this situation…zero, nada, zilch etc.

[thepossum]

I wanted to say much the same but did not have the confidence or expertise to say it

Some of us still play poorly shuffled rubber bridge too

[jillybean]

It is good to know I can completely disregard this remark. It is alarming how these bridge rumours take hold, and who doesn't want to sound intelligent at the table?

I don't consider Declarer a fool at all but as always, I do appreciate your succinct approach, Mike.

[Cyberyeti]

You want a more interesting "is it a restricted choice" situation, try this one, interesting in the bidding and the play: Teams, I will foist our system on you.

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2N was GF not necessarily balanced, 3♠ showed basically a 3334 10-11

Plan the auction from there, also plan the play 6♠ when opps start with 2 rounds of diamonds, you ruff, cash ♠A and the 10 drops on your right.

[nullve]

Cyberyeti, on 2024-November-10, 14:20, said:

opps start with 2 rounds of diamonds

Details?

[smerriman]

jillybean, on 2024-November-10, 07:30, said:

It is good to know I can completely disregard this remark. It is alarming how these bridge rumours take hold, and who doesn't want to sound intelligent at the table?

I've been trying to figure out what they could possibly have even been imagining.. if you're playing against extremely weak opponents who you know will always follow suit with their lowest spot card (i.e. 8 must be from Q8 or 8, but never 8x or Q8x), then it is true that someone who plays the 8 to the first round is slightly more likely to have the queen. But that knowledge doesn't even help you anyway, since you've seen their second card before deciding whether to finesse or not..

[Cyberyeti]

nullve, on 2024-November-10, 14:25, said:

Details?

Ace cashed, encourage, small to the Q

[mike777]

Will not finesse spade
Jxxx vs jT or JTx
As for auction
Partner has exactly as promised

So close but with known double fit. 4C

Btw partner might open that,11
Despite 3334
That pushes me there..
😊 😊

I guess I could bid 4C
Pard bids 4H
That's good news but still
If I key card I get to 6..

[Cyberyeti]

mike777, on 2024-November-10, 16:10, said:

Will not finesse spade
Jxxx vs jT or JTx
As for auction
Partner has exactly as promised

So close
I guess I could bid 4C
Pard bids 4H
That's good news but still
If I key card I get to 6..

My point about the auction was that 6♥ is better than 6♠ if partner has 2x Kxx

You make the correct point about the play, stiff 10 or J is more likely than J10, but any decent player false cards with J10x so this is not a proper restricted choice situation

[mike777]

Ya. 6H much better

However many of us including myself would find getting to 6H very tricky, especially at the table, under time pressure.

Just getting to six spades is not easy...
😊

[nullve]

Dummy: A973
Declarer: KJT65

1. K-2-3-8
2. J-4-?

Suppose Declarer knows that RHO is someone who would just as likely play the Q(!) as the 8 from Q8.

Does restricted choice apply or not?

[thepossum]

Isn't restricted choice are rather grandiose name for conditional probability? I still don't understand the fuss over it
I get anxious even saying I feel I am missing something but duh
If A doesn''t do seomthing the remaining probability that B will do it goes up?? or is it something really complicated that only John Nash would understand
What is the chance declarer is considering restricted choice when you play your Jack

I do like those other rules thatused to apply in the days of bad shuffling and old rather sticky decks of cards - that's a new one. Which players had been eating cake earlier

[DavidKok]

Yes, restricted choice is just conditional probability. In particular, it draws attention to the fact that with certain holdings an opponent had a choice regarding which card to play, and therefore the probability of them playing the card you've seen conditional on them having a specific holding is not 100% (typically it's 50%, which is the most common scenario). If you plug that number into Bayes' theorem the posterior likelihood of particular holdings is different from a naive assumption of assigning 100% to the inference.
This is also known as 'the Monty Hall problem' outside bridge circles.

If RHO is just as likely to play the Q as the 8 from Q8 in that scenario then restricted choice does apply.

What's interesting from a Bayesian point of view is that the result still holds on average if we do not make assumptions about the carding of the opponents (as is the original Monty Hall problem against the rules of the show host). In a way, the result is robust against having to specify the habits of the defenders.

[pescetom]

 DavidKok, on 2024-November-11, 04:52, said:

This is also known as 'the Monty Hall problem' outside bridge circles.

I confess I found it very difficult to accept the explanation at first.
Although on reflection no surprise that

Quote

Pigeons repeatedly exposed to the problem show that they rapidly learn to always switch, unlike humans.

I somehow suspect they would learn defensive play more quickly too.