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Alerting mixed strategies

#1 User is offline   Fluffy 

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Posted 2012-May-15, 05:24

I play on a partnership the following response to 1 opening:

1-2 = 8-10 raise in spades or (hardly ever) invitational with hearts
1-2 = 0-7 raise in spades (preemptive)


Since we are on a strong club context and 1 is limited, Right now the 1-2 has become like telling the oponents: you are stupid if you let us play this.

To avoid it we are thinking about using some mixed strategies, biding 2 on doubleton spade, and bidding 2 with some crappy hands as well.

What would be the correct explanation for this bids?
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#2 User is offline   Cthulhu D 

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Posted 2012-May-15, 05:37

This is not a contribution on how to alert it, but I bet it would be interesting. Run an experiment on what % of the time 4th seat balances if you explain it as

'a pre-emptive spade raise or a balanced hand with 2 spades' vs 'a balanced hand with 2 spades or a pre-emptive spade raise'
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#3 User is offline   paulg 

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Posted 2012-May-15, 05:43

I'm not sure who is more stupid - a pair who lets the opponents play in two spades when they have a maximum of 22 points, or a pair who uses both 2 and 2 to show 0-10 points with some level of random spade support.
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#4 User is offline   gnasher 

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Posted 2012-May-15, 05:51

 Fluffy, on 2012-May-15, 05:24, said:

What would be the correct explanation for this bids?

2 = Any 8-10 raise in spades, or x% of the 0-7 raises in spades, selected at random.
2 = y% of the 0-7 raises in spades, or z% of hands in the a-b range with two spades, both selected at random.
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn
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#5 User is offline   fromageGB 

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Posted 2012-May-15, 09:46

deleted, misinterpretation

This post has been edited by fromageGB: 2012-May-15, 09:47

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#6 User is offline   fromageGB 

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Posted 2012-May-15, 09:53

 gnasher, on 2012-May-15, 05:51, said:

2 = Any 8-10 raise in spades, or x% of the 0-7 raises in spades, selected at random.
2 = y% of the 0-7 raises in spades, or z% of hands in the a-b range with two spades, both selected at random.

Would X and Y sum to 100? Maybe not - you can pass on (100-x-y)% so that opponents cannot assume a fit.
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#7 User is offline   Vampyr 

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Posted 2012-May-15, 19:19

 gnasher, on 2012-May-15, 05:51, said:

2 = Any 8-10 raise in spades, or x% of the 0-7 raises in spades, selected at random.
2 = y% of the 0-7 raises in spades, or z% of hands in the a-b range with two spades, both selected at random.


Are "random" selections truly random? I wouldn't be surprised if a pattern existed.
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#8 User is offline   barmar 

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Posted 2012-May-16, 13:41

I think we had a thread a while ago (at least a year I think), probably in one of the Laws forums down below, about whether such an agreement is even allowed by most convention regulations. A big problem was in how someone would be expected to adhere to the described probabilities -- you can't throw dice at the table. We talked about ways that you might get the random info from your hand, e.g. the number of odd or even pips. If you come up with a good algorithm there will be a pattern, but not one that can be used to discern anything useful about your hand.

#9 User is offline   Cthulhu D 

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Posted 2012-May-16, 19:19

 barmar, on 2012-May-16, 13:41, said:

I think we had a thread a while ago (at least a year I think), probably in one of the Laws forums down below, about whether such an agreement is even allowed by most convention regulations. A big problem was in how someone would be expected to adhere to the described probabilities -- you can't throw dice at the table. We talked about ways that you might get the random info from your hand, e.g. the number of odd or even pips. If you come up with a good algorithm there will be a pattern, but not one that can be used to discern anything useful about your hand.


Is this the thread? http://www.bridgebas...rting+%2Brandom

It's a slightly different situation.

Edit: Wait no, it's probably this one http://www.bridgebas...__1#entry572575

The method of randomization via shuffling cards is flawless and does not disclose infomation about your hand. You'd just have to remember to do it at the start of every hand. Alternatively adding the sum of your spot cards and the seconds hand of your watch and dividing will generate randomish numbers.

Okay no you have to do the shuffling approach. A good idea anyway, you can 'preload' a truely random number every hand for playing from tight honours if nothing else.
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#10 User is offline   kenberg 

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Posted 2012-May-17, 04:26

Just speaking as a player, not (at all) like a laws expert, I would be satisified if 1S-2S were explained as a (perhaps very) weak raise, sometimes on two cards. It is fairly common for the auction 1S-1NT(forcing)-2something-2S to occur on a doubleton, and it has never crossed my mind that someone who uses this approach is obligated to tell me in percentage terms what the chances are that it could be a doubleton.. I assume that (with possibly rare exceptions) opener passes 2S. The explanation should be clear enough that opponents will understand this to be the case.

I'll have to think about the 2H bid.

I know you were asking more for a rules based answer, but one can always hope that the rules and what I think of as common sense are not too far out of whack. One can hope.
Ken
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#11 User is offline   gnasher 

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Posted 2012-May-17, 05:42

 kenberg, on 2012-May-17, 04:26, said:

Just speaking as a player, not (at all) like a laws expert, I would be satisified if 1S-2S were explained as a (perhaps very) weak raise, sometimes on two cards. It is fairly common for the auction 1S-1NT(forcing)-2something-2S to occur on a doubleton, and it has never crossed my mind that someone who uses this approach is obligated to tell me in percentage terms what the chances are that it could be a doubleton.


There's a difference between
(1) The probability that, given a hand with a doubleton of a given strength, they would bid 2S.
(2) The probability that 2 could be a doubleton, now that they've bid it.

(1) is a matter of agreement and subject to disclosure. (2) is a matter of arithmetic, so obviously not subject to disclosure, but we can't calculate or estimate (2) unless we know (1).

I don't understand why you wouldn't want to know (1). Suppose that 99 times out of 100 they would bid 1NT instead, so that (1) is only 1%. Surely that would affect your action either in the bidding or the play?
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn
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#12 User is offline   kenberg 

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Posted 2012-May-17, 06:11

I suppose if a pair had an agreement to mostly always raise 1S -2S whenever they held minimal values and two card support I should know that. I doubt that is the case. And I doubt that it is random, or at least I would not agree to play it as random with a partner. If I know that my partner will always pass 2S, or almost always pass 2S, I would raise on a doubleton when I thought 2S in a 5-2 fit has a reasonable shot at being a good contract and not otherwise. Qx would be more inspiring than xx. I think that there is something to be said for allowing the (partial) explanation "2S means that he wants to play 2S". Actually I have (although rarely) raised on Qx and not with a precision partner.

If the choice truly is simply random, that presents a bigger problem I don't know what to say if a pair decides to make random decisions about a choice of bids. No doubt there might, in some circumstances, be a legitimate game theory justification for such an approach. I suppose they could have an agreement such as raise on two if the number of spot cards in the minors is even, or divisible by 3, or not divisible by 3, or some such.
Ken
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#13 User is offline   Cthulhu D 

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Posted 2012-May-17, 22:52

The point though is that it's very appealing to balance over 1S-(P)-2S where 2S is 0-7 with 4 spades - you have law protection and half the deck, and 2S will probably make or go 1 off for a very good score for the precision pair

However if 2S is 2 spades balanced, 5 to 7 ish, it's not very appealing to balance.

As the OP is playing A currently, it makes sense to put some of hand type B in with the type As, mostly to give the opponents an ulcer when it comes to balancing. However, he's not planning to bid 2S with all 5-7 balanced hands with 2 spades, he's just going to do it sometimes. Full disclosure of the % of hands that are eligible for the raise that he will actually do it with is probably worth full disclosure.
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#14 User is offline   mike777 

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Posted 2012-May-18, 00:28

 Fluffy, on 2012-May-15, 05:24, said:

I play on a partnership the following response to 1 opening:

1-2 = 8-10 raise in spades or (hardly ever) invitational with hearts
1-2 = 0-7 raise in spades (preemptive)


Since we are on a strong club context and 1 is limited, Right now the 1-2 has become like telling the oponents: you are stupid if you let us play this.

To avoid it we are thinking about using some mixed strategies, biding 2 on doubleton spade, and bidding 2 with some crappy hands as well.

What would be the correct explanation for this bids?



not sure what your question is......it seems you have explained your bids.
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#15 User is offline   blackshoe 

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Posted 2012-May-18, 16:10

 Cthulhu D, on 2012-May-17, 22:52, said:

Full disclosure of the % of hands that are eligible for the raise that he will actually do it with is probably worth full disclosure.

What percentage of players playing this method do you think have even thought about, much less calculated, this percentage of hands. If you ask the players playing this method, at the table, this question, what kind of answer to you think you'll get. I'd bet on "I have no idea", or the like.
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#16 User is offline   Vampyr 

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Posted 2012-May-18, 19:22

 blackshoe, on 2012-May-18, 16:10, said:

What percentage of players playing this method do you think have even thought about, much less calculated, this percentage of hands. If you ask the players playing this method, at the table, this question, what kind of answer to you think you'll get. I'd bet on "I have no idea", or the like.


In that case they probably should not be playing this method.
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#17 User is offline   nige1 

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Posted 2012-May-18, 20:23

I suggested a method for triggering psyches on BLML, which Fluffy can adapt for his purpose. Instead of shuffling your cards or looking at your watch, you can specify particular small-cards as triggers. A trigger can be any set of cards in any suits. For example, suppose you want to raise to 2 on about 10% of hands with 0-7 HCP and a doubleton . Just wait for 0-7 counts with a doubleton that contains, say, 2. If partner knows what your trigger is, then you must also disclose it to opponents. IMO this is not encrypted because it is more likely that an opponent holds your trigger than partner.
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#18 User is offline   Cthulhu D 

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Posted 2012-May-18, 23:04

 blackshoe, on 2012-May-18, 16:10, said:

What percentage of players playing this method do you think have even thought about, much less calculated, this percentage of hands. If you ask the players playing this method, at the table, this question, what kind of answer to you think you'll get. I'd bet on "I have no idea", or the like.


Sure, but Fluffy has obviously thought about it, and if you have, surely disclosing that % is mandatory for 'full disclosure' So given that, how do you disclose it!
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#19 User is offline   rbforster 

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Posted 2012-May-19, 10:18

How do people decide when to make a 3 card very weak raise via 1M-1NT...2M vs just passing? I think just saying what the two hand types are is sufficient and leaving how often you decide to bid one vs the other to "bridge judgment". That's what all the standard players do when faced with a choice.
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#20 User is offline   gnasher 

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Posted 2012-May-20, 02:22

 rbforster, on 2012-May-19, 10:18, said:

How do people decide when to make a 3 card very weak raise via 1M-1NT...2M vs just passing? I think just saying what the two hand types are is sufficient and leaving how often you decide to bid one vs the other to "bridge judgment". That's what all the standard players do when faced with a choice.

If you use bridge judgement to make the decision, it's fine to say or imply that this is what you do. If you're actually making a random decision, it would be misleading, and therefore against the rules, to imply that you use your judgement.
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn
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