Your bid?

[the hog]

Imps. V vs NV

 

Qxxx

Jxxxx

xx

Qx

 

(1S) 2H (P) ?

[pbleighton]

Vul at IMPs, I bid 4H and hold my nose.

 

Otherwise, I would bid 3H.

 

Peter

[pclayton]

Pass. Don't want to tell them about their 20 point game or 26 point slam.

[nickf]

I'm not really a law fan but this hand says bid 4H now really really loudly.

 

nick

sydney

[paulg]

Despite an initial reaction to bid 4♥, I feel that all the danger signs are there to only bid 3♥.

 

Partner has not doubled, RHO has not raised spades, entries to my hand are very poor and so I will only raise competitively giving partner the option of getting it wrong.

 

Very tough decision.

 

Paul

[Fluffy]

If you want to 'psycke' your ♥ holding it is normally right to do it by 3 cards, so bid as if you had 2: pass.

[pbleighton]

"I'm not really a law fan but this hand says bid 4H now really really loudly."

 

I agree with 4H, but the fourth spade reduces the volume considerably :(

 

Peter

[flytoox]

4H is very wrong, RHO didnt raise spade. This is a very dangerous sign. If RHO raise to 2S, then pd rates to have singleton and I will bid 4H as well.

 

 

Here RHO passed, so I will pass too. If there is some balance, I will bid 3H later, but not now.

 

YOu can imagine def starts with spade lead, and you lose three spade tricks quickly. It is even possible they have a trump uppercut.

[hrothgar]

As usual, I think that a mixed strategy is best

 

Pass = 20% of the time

3H = 20% of the time

3N = 25% of the time

4H = 15% of the time

5H = 20%

 

The relatively uniform distribution suggests a very tough hand with no clear favorite bid.

[flytoox]

As usual, I think that a mixed strategy is best

 

Pass = 20% of the time

3H = 20% of the time

3N = 25% of the time

4H = 15% of the time

5H = 20%

 

The relatively uniform distribution suggests a very tough hand with no clear favorite bid.

mixed strategy is right only if the payoff to all these bids are same. This is impossible in the given sequence.

[hrothgar]

mixed strategy is right only if the payoff to all these bids are same. This is impossible in the given sequence.

Mixed strategy is right only if the EXPECTED payoff is the same

[luke warm]

i can't afford to pass, it's possible my rho is completely busted and partner is the beast at the table... the normal bid, 4H, might not work here... i'll bid it if i have to, but for now i think 3H is enough, giving partner a chance to show more if he wants to

[flytoox]

mixed strategy is right only if the payoff to all these bids are same. This is impossible in the given sequence.

Mixed strategy is right only if the EXPECTED payoff is the same

RIght. still, here how can you have a mixed strategy? Strictly speaking, this is a decision makig problem. There is no strategic interaction here. Cos so far pd and opp's decicision didnt rely on your bid of, from pass to 5H.

[Antoine Fourrière]

4♥. I don't think my hand warrants five opposite a 5422 or 5431 (which can't be with short spades imo), but either opener or partner is going to bid again if I do less, and I don't want opener to show a minor economically.

[pclayton]

I'm not really a law fan but this hand says bid 4H now really really loudly.

 

nick

sydney

I think the balanced nature of the hand reduces the TT by at least one, maybe more, since my ODR isn't great.

[EricK]

mixed strategy is right only if the payoff to all these bids are same. This is impossible in the given sequence.

Mixed strategy is right only if the EXPECTED payoff is the same

RIght. still, here how can you have a mixed strategy? Strictly speaking, this is a decision makig problem. There is no strategic interaction here. Cos so far pd and opp's decicision didnt rely on your bid of, from pass to 5H.

What a mixed strategy gives you is not different bids for this hand but different hands for each of your bids. If 4♥ is always 5 card support, 3♥ is always 4 card support, 2♠ is always strong with 3 card support etc it gives the opponents too easy a time.

 

Eric

[hrothgar]

RIght. still, here how can you have a mixed strategy? Strictly speaking, this is a decision makig problem. There is no strategic interaction here. Cos so far pd and opp's decicision didnt rely on your bid of, from pass to 5H.

Bridge bidding can can/should be modeled as a multi-stage game. The set of available bids and definition of the available bids is contingent on earlier stages of the game.

 

You are completely correct that the specific meaningss of bids during earliier stages of the game do not change based on my current bid. However, my choice of bids this round will very much impact future bids by the opponents.

 

As a simple illustration, the entire problem can be considered as equivilent to output choices in a Stackelberg Equilibrium...

[EricK]

As a simple illustration, the entire problem can be considered as equivilent to output choices in a Stackelberg Equilibrium...

Well, I'm glad that has clarified matters...

[mike777]

3H rather than 4 because

 

1)no spade raise

2) Qxxx of spades.

[hrothgar]

As a simple illustration, the entire problem can be considered as equivilent to output choices in a Stackelberg Equilibrium...

Well, I'm glad that has clarified matters...

 

In Economics, one of the "classic" problems studies how firms decide the quantity that they should produce. Historically, economists focused on two polar extremes:

 

Under perfect competition, the number of firms is assumed to be infinite.

Under monopoly there is only one firm.

 

Both of these extreme conditions make life very easy since there is no "strategic" interaction. The output decision of the firm being studied does not depend on the output decision of any other firm.

 

Life gets much more complicated when one is studying "Oligopoly". Here, the output decision of one firm depends on the decisions made by other economic actors. Here, the simpliest model is so-called Cournot Duopoly. A Stackelberg equilibirum is a more complex condition in which one firm is assumed to have a dominant market position. The behaviour of other firms is conditional on the decisions made by the Stackelberg leader.

 

Stackelberg's model provides a good basic introduction to the dynamics introduced by multi-stage games...

[Cascade]

As usual, I think that a mixed strategy is best

 

Pass = 20% of the time

3H = 20% of the time

3N = 25% of the time

4H = 15% of the time

5H = 20%

 

The relatively uniform distribution suggests a very tough hand with no clear favorite bid.

Are these percentages calculated or guesses?

[hrothgar]

As usual, I think that a mixed strategy is best

 

Pass = 20% of the time

3H = 20% of the time

3N = 25% of the time

4H = 15% of the time

5H = 20%

 

The relatively uniform distribution suggests a very tough hand with no clear favorite bid.

Are these percentages calculated or guesses?

Sorry to say that I pulled the numbers out of my butt...

 

Solving these types of problems is VERY difficult.

 

1. As I noted earlier, bridge is a multi-stage game. A bidding decision during one round of the auction impacts every other round of the auction. Worse yet, the "bidding game" also impacts the play of the hand... (As an example, a number of game theorists have studied Poker, however, they focus on 5 card draw or Hold-Em rather than 7 card stud)

 

2. The payoff matrix for the bidding game depends on how effective the opponent's are at countering the strategy in question.

 

I'd be very surprised to ever seen a clean analytical proof that is able to provide definitive percentages.

[flytoox]

RIght. still, here how can you have a mixed strategy? Strictly speaking, this is a decision makig problem. There is no strategic interaction here. Cos so far pd and opp's decicision didnt rely on your bid of, from pass to 5H.

Bridge bidding can can/should be modeled as a multi-stage game. The set of available bids and definition of the available bids is contingent on earlier stages of the game.

 

You are completely correct that the specific meaningss of bids during earliier stages of the game do not change based on my current bid. However, my choice of bids this round will very much impact future bids by the opponents.

 

As a simple illustration, the entire problem can be considered as equivilent to output choices in a Stackelberg Equilibrium...

Not quite same as Stackleberg problem. Here you really dont know if you will be the leader or follower. Also, in the stackleberg problem, there is credible committment. And you are not punished by being aggressive. However, in competitive bidding, you are very likely to be punished by overbid.

 

 

THe area I think mixed strategy applies most is falsecard. Say throw 9 from T9x. The reason why this kind false card is always effective is that declarer cannt be sure if you are falsecard or playing honestly.

 

I definitely agree with you that game theory concept can be used in bridge. But I dont think this is the right occasion.

[the hog]

"I can't afford to pass, it's possible my rho is completely busted and partner is the beast at the table"

 

Ok this is a hand from the weekend's gnot final, and Jimmy hit the nail right on the head. You CAN'T afford to pass.

 

I held

void

AQxxxx

AKxx

Kxx

Now don't say "that is a X". I disagree with that with a good 6 card H suit. Partner passed, which I feel is a HUGE position. Opener bid 3S, I x again, lefty made a totally idiotic bid of 4S and I doubled again all pass.

 

This went for 500, but we are cold for 6H on the 1-1 break, and "yes" had pd bid 4H. I was going to look for slam.

 

Note what partner has done. By not supporting H he has:

* caused us to miss a slam

* caused m to totally overvalue the H suit in a defensive capacity. I cashed 2 Ds, the A of H and tried another H and fell off my seat when this gave the opps a ruff and sluff, not that it cost!

 

I think this hand is worth 4H - Nickf, (Nick Fahrer form Australian Bridge Mag by the way), is on the ball - you have 5 card support, you have 2 doubletons and a probable working Q; pd has made a vul overcall. Seriously, what more do you want?

[flytoox]

"I can't afford to pass, it's possible my rho is completely busted and partner is the beast at the table"

 

Ok this is a hand from the weekend's gnot final, and Jimmy hit the nail right on the head. You CAN'T afford to pass.

 

I held

void

AQxxxx

AKxx

Kxx

Now don't say "that is a X". I disagree with that with a good 6 card H suit. Partner passed, which I feel is a HUGE position. Opener bid 3S, I x again, lefty made a totally idiotic bid of 4S and I doubled again all pass.

 

This went for 500, but we are cold for 6H on the 1-1 break, and "yes" had pd bid 4H. I was going to look for slam.

 

Note what partner has done. By not supporting H he has:

* caused us to miss a slam

* caused m to totally overvalue the H suit in a defensive capacity. I cashed 2 Ds, the A of H and tried another H and fell off my seat when this gave the opps a ruff and sluff, not that it cost!

 

I think this hand is worth 4H - Nickf, (Nick Fahrer form Australian Bridge Mag by the way), is on the ball - you have 5 card support, you have 2 doubletons and a probable working Q; pd has made a vul overcall. Seriously, what more do you want?

You know pd is likely to pass, and still you just overcall 2H. So you want to blame for his pass. What is wrong with dbl? Why cannt you dbl with 6Hearts?