The difference between promise bluff and double bluff

[KuronoJoucho]

· As we know, the key point of promise bluff is to tell someone that he has the connected card of the prompted card.
· Let's take an example to explore the difference, for example, in a four-player game with 5 color · (the order of players is Alice, Bob, Cathy, Donald).
· No colors are played on the field.
· Alice, as the first player, used white to prompt Donald's white 3, which is far from 2 playable (1-2-3).
· Bob first did not see that others had white 1, he successfully played the first card blind, but it was not white 1, but 1 of other colors（black 5 ）
· What should Cathy do at this time?
· According to the meaning of promise bluff, we understand that if Cathy saw that Bob had white 2, she should not play the card, and Bob would get the promise that he had white 2 in the second position at this time, completing this promise bluff.
· At this time, Cathy did not see that Bob had white 2, regardless of whether other players had it.
·But Cathy also knows that she can't know whether she has white 2, so this white 3 clue is not a legitimate target, and Donald, as the recipient of the clue, will get an error message, and he will write his white 3 as white 2, and an accident will happen in the future.
·So Cathy now understands that she is forced by Alice to blind play the first card, and it is played successfully. This card can be any other 1 (but it can't be white 1), or it can be a 2 of the same color connected to the card played by Bob.
·Since two blind plays are triggered immediately, Donald writes his white as white 3, and the clue ends.
·Why shouldn't this be a promise bluff? Because Cathy didn't see the white 2.
·Then there is another point to note. If in this example, any player has a white 2 that has been marked but not played, after the white 3 is prompted, Bob plays the first unrelated card, and others should not continue to play cards, and this bluff clue ends (this is indeed a promise bluff, because everyone sees the real white 2, and it is a single bluff).
·But I wonder who invented the promise bluff? For example, is the promise bluff without the white 2 symbol only applicable to 3-player games? Because we know that in a 3-player game, Bob should only blindly play one card, and Donald, as the clue recipient, will not play any cards, so the clue will stop immediately.
· Therefore, I think that in 4 players or more, this clue needs to be understood as a double bluff, and Cathy needs to blindly play the first card as a double bluff.
· This double bluff is recognized by most master players, but some players still think this is a promise bluff
· This is what I think is the most essential difference between promise bluff and double bluff.

[Jellby]

Cathy sees that a white clue on Donald caused a blind clue from Bob, and there's no way Donald will bomb after the bluff has been revealed. Cathy assumes she has 2w in finesse position and doesn't play anything. I think this is just a promise bluff.

It would have been different if the clue on Donald had been 3 and not white. Then Cathy sees that the card played by Bob is indeed not the correct 1, and if she doesn't do anything Donald will bomb trying to find the 2 that connects the 1 to his 3. So Cathy plays blind, knowing it has to be a bluff, and assuming nothing about 2w.

[KuronoJoucho]

·But the promise bluff itself requires Bob to have white 2 (this is the determining condition for Promise bluff to make others play only one card and to determine that it is white 3). If Cathy does not play any cards, the white clue on white 3 will lie to everyone that everyone has white 2, especially Donald, who will directly play white 3 after looking for white 1.
·Therefore, this clue clearly requires Cathy to play blind to distinguish from the promise bluff, otherwise the clue will become a bad clue and make the team fail.

[KuronoJoucho]

https://spoo.me/NVeHYa

[Blacktango]

Hi. Such a W clue on a W3 promises a W2 somewhere.

Bob and Carole don't see W1-W2, so they think they have both in left most position.
Bob plays their left most which is NOT W. Now the bluff is revealed to everyone, so no need more answers.

Since the clue was on a W3 and a W2, it means that there is a W2 somewhere.
Bob thinks that he has it 2nd slot from his finesse position.
Cathy believes that she has it, in finesse position
Donald doesn't see the W2 in Bob and Cathy's hand, so he thinks that the marked card is the W2.

No one but Alice knows that there is no W2 here.

[Blacktango]

I wouldn't call this clue a promise bluff, but just a basic (fake) bluff.
All bluffs promise something, at least that the marked card has a value equal to one more than the real playable value.

Eventually, the bluff can be delayed (Cathy and Donald will wait that the M1 + W1 are played):



But IMO such a clue is the more dangerous the more players you play with, because the bluff is revealed only after a delay, and maybe someone (e.g. David) can break it and clue R to Carole. So the risk is probably not worth it.

[KuronoJoucho]

So what I want to explain most here is that there are two kinds of people who think this clue is a promise bluff.
1. Those who think that someone has w2 (Cathy does not play the first card)
2. Those who think that w3 is playable (Cathy should play the first card)
Obviously, those who think it is a promise bluff belong to the first part, why is there such a difference?
First of all, look at the clues. Everyone knows that the color clue itself should be called a certain card to play, and the number is a certain card that should be played or saved. Since it is a color clue, bluff white 3 play, why does this clue become a promise white 2?
And in order to immediately correct the clue that the w3 player wrote as w2, Cathy should immediately blind play for this clue (the most important thing is that she understands that this wrong clue should be corrected).
The thinking gap between the two players is also exposed, so does everyone agree that this is a double bluff?
In addition, your DB is what I want to say, the blind play of r1 is to correct the mismatch between MC1 and the white clue (similar to Cathy).

[Blacktango]

The difference with the Delayed Bluff, is that no bluff is revealed from Bob's plays.

In your first example, Bob played a card with a color that doesn't match the clue.
I agree that Bob's play doesn't reveal that the W isn't W2.

The promises of the bluffs are a convention.
We could clue B a B5 with no B card played, to make a R1 played as a blind answer, just to avoid the player bombing the B5 as a B1.
But this would be so less efficient! With promise, you don't need to reclue the marked card, which saves a lot of tokens.

You could add the convention you explained: Cathy should blind play to reveal the fake promise.
This is compatible with the basic promise convention.
But it is not with the "long promise bluff" convention (a.k. there is a W2 in finesse position somewhere, which is now known).

Which of these conventions is better is debatable.
IMO, the blind play from Cathy's a bit more arbitrary because no more answer is required at this moment.
And the long promise bluff fits well (and logically) with the basic promise convention.

[Blacktango]

These previous examples are different from what I usually call "finesse + bluff" and "double bluff".






In those both situations, Cathy has to answer right away to reveal the bluff and avoid David to bomb.

[KuronoJoucho]

·Your example is a very common db, and I have mastered it. But thank you for answering many of my questions above. It turns out that these disputes depend on the conventions used by players. I follow the H-Group community conventions, which are very different.
·At least in my case, people who follow the H-Group rules must let Cathy play cards, which conflicts with the convention that Cathy does not play cards.