[nullve]

From the 'variable NT range' thread:

Shugart23, on 2016-January-09, 17:16, said:

I know what you are saying. I can still also see kens argument that opening 1nt in the heart/no heart scenerio is indeed a 3 point range. It is just that nobody knows which range it is until the rebid. Having said that, i am not going to try it !

helene_t, on 2016-January-09, 17:53, said:

You could also try:

12-14 if I have less than 15 points
15-17 otherwise

In a somewhat different vein, suppose M and M' are two different legal meanings of a call c and that

c =

M if P is true
M' otherwise,

where P is a proposition not necessarily about bridge, e.g. one of

* 'Holocaust took place.' (almost universally accepted as true)
* 'Global warming is real.' (slightly more controversial, perhaps)
* 'God exists.' (many believe it, many don't)
* 'Peanuts are nuts.' (I was recently shocked to find out they're not)
* 'Justin Bieber just broke up with Selena Gomez.' (an annoying bit of trivia if true, but according to Wikipedia they had already broken up in 2013)
* some lofty mathematical result (not open to debate, but not exactly common knowledge either)

Would someone playing this be required to state whether they believed P to be true?

(c could also be a defensive signal, of course)

[jnichols]

nullve, on 2016-January-11, 18:45, said:

Would someone playing this be required to state whether they believed P to be true?

Yes

[mgoetze]

You're obligated to explain what your bids mean, not pose riddles to the opponents. If you try this I would hope the director would give you a PP for slow play.

[nullve]

mgoetze, on 2016-January-11, 19:10, said:

You're obligated to explain what your bids mean, not pose riddles to the opponents. .

But there doesn't have to be a simpler underlying meaning. A pair could agree to play e.g.

1N =

15-17 if global warming is real
12-14 otherwise,

couldn't they? Then if the players disagree on whether global warming is real, the agreed meaning couldn't be simplified to just '15-17' or just '12-14'.

[sfi]

In other words, the real agreement is North shows 12-14 when opening 1NT while South shows 15-17. There is nothing in the laws stopping a partnership from doing that, but most jurisdictions have regulations that say the partners must be playing the same system. So you are unlikely to be able to play this in most places.

Wrapping it up in a sophism does not change the nature of the agreement. And if you tried to explain it that way to opponents in a serious competition, I suggest you should expect a penalty for doing so. And rightfully so IMO.

[nullve]

sfi, on 2016-January-11, 19:56, said:

In other words, the real agreement is North shows 12-14 when opening 1NT while South shows 15-17.

Maybe they take for granted, or are willing to gamble, that they have similar views on global warming and therefore play the same range.

[sfi]

My apologies - I thought you were actually trying to make a sensible, if misguided, point. I'll be off now.

[helene_t]

Fisher-Schwarts got away with playing "we are in a forcing pass situation if and only if the opponents are not"

There was a pair in Amsterdam who played that a double of 3NT asks for a spade lead if both opps are wearing eyeglasses. This was not a joke but was based on the misguided belief that since the spade lead is what you would ask for about 40% of the time the optimal strategy is a mixed strategy that allows you to ask for a spade lead 40% of the time.

That is of course OK. As someone else said in the other thread: the test is if you can announce it as a 3-point range. In this case you just look at the opps and count their eyeglasses, and then you announce the meaning of the call.

[WellSpyder]

helene_t, on 2016-January-12, 02:20, said:

In this case you just look at the opps and count their eyeglasses, and then you announce the meaning of the call.

I thought you were supposed to explain your agreement, not the meaning of the call...

[Vampyr]

WellSpyder, on 2016-January-12, 02:57, said:

I thought you were supposed to explain your agreement, not the meaning of the call...

Ideally these should be the same.

[Lanor Fow]

I remember hearing about a carding agreement where carding was upside down if the original lead was odd and 'standard' if it was even.

[barmar]

161d says that players may use

Quote

information that the player possessed before he took his hand
from the board (Law 7B) and the Laws do not preclude his use of this
information.

I presume the Lawmakers meant this only to refer to bridge-related information, not totally unrelated information like botany, popular culture, world history, etc. They thought this was so obvious that it went without saying, so they didn't say it explicitly.

[Cyberyeti]

Lanor Fow, on 2016-January-12, 08:59, said:

I remember hearing about a carding agreement where carding was upside down if the original lead was odd and 'standard' if it was even.

I met a pair that used to vary depending on whether the sum of dummy's lowest card of each suit was odd or even.

[barmar]

Cyberyeti, on 2016-January-12, 10:07, said:

I met a pair that used to vary depending on whether the sum of dummy's lowest card of each suit was odd or even.

I think both of these agreements should be legal. The information is available to declarer just as easily as to the defenders. It's not like "encrypted" signals, where the key is information that the defenders can infer from their own hands, which aren't visible to declarer.

[Vampyr]

barmar, on 2016-January-12, 10:37, said:

I think both of these agreements should be legal. The information is available to declarer just as easily as to the defenders. It's not like "encrypted" signals, where the key is information that the defenders can infer from their own hands, which aren't visible to declarer.

I suspect that one or both of these pairs were trying to play games with non-disclosure. "What are your signals?" "Reverse" and then declarer doesn't ask on the next hand...

[barmar]

Vampyr, on 2016-January-12, 11:16, said:

I suspect that one or both of these pairs were trying to play games with non-disclosure. "What are your signals?" "Reverse" and then declarer doesn't ask on the next hand...

Ugh.

Lots of pairs have different carding agreements depending on whether it's NT or a suit contract. When I'm in that situation, and I'm asked about our defense, I say something like "Since it's NT, we play ...." That way, the opponents know not to make assumptions on the next hand.

If the agreement is based on the cards in dummy, or the lead, that should be disclosed to avoid misleading the opponents. They should at least qualify it with something like "on this hand, we play ...."

[gwnn]

What about "1NT shows that the natural logarithm of my HCP has the second digit after the decimal point 5?" That's presumably a better method since the definition is completely objective (there are severe problems with the definition of "break up", let alone applying it in practice - much more so than the definition of ln(x) and counting HCP) I would punch anyone in the face who alerted like this, and as a director, I would high-five anyone who punched the alerter in the face.

[Zelandakh]

"Take the number of HCP in dummy and add 1905 - if the winner of the World Series of that year was from the NL we play standard carding, if from the AL we play upside down" could perhaps be a completely accurate description of a pair's agreements but I would hope that no TD would regard it as full disclosure even though the information is just as freely available to the defenders as declarer...

[mgoetze]

gwnn, on 2016-January-13, 04:10, said:

What about "1NT shows that the natural logarithm of my HCP has the second digit after the decimal point 5?"

Here's something you will appreciate: at a fun event here in Germany I once played against a pair playing "Pi carding". Cards corresponding to digits near the decimal point are even/positive, and cards corresponding to digits further away from the decimal point are odd/negative.

[barmar]

gwnn, on 2016-January-13, 04:10, said:

What about "1NT shows that the natural logarithm of my HCP has the second digit after the decimal point 5?" That's presumably a better method since the definition is completely objective (there are severe problems with the definition of "break up", let alone applying it in practice - much more so than the definition of ln(x) and counting HCP) I would punch anyone in the face who alerted like this, and as a director, I would high-five anyone who punched the alerter in the face.

This is amusing, because I'm having trouble coming up with a good objection to it. If someone says "I should only have to know bridge-related information, not math", you can counter "Of course you have to know math -- adding HCP, counting cards, calculating probabilities, etc." Drawing the line such that logarithms and Pi are outside seems totally arbitrary.