matchpointitis

[Finch]

[hv=pc=n&s=sqt84hakj5dj6cq84&n=s6hq6dak95432caj6&d=n&v=0&b=1&a=1dp1hp3dp3nppp]266|200[/hv]

 

Playing matchpoints.

LHO leads the 2 of spades (attitude) to RHO's king.

RHO returns the 5 of spades (RHO will give count here i.e. return lowest for 4 original and top of 3 original, although sometimes might lead an asystemic card to finesse declarer)

You play a spade of your choice and LHO beats it cheaply.

 

LHO thinks for quite a long time and plays a highish club. You put up the ace.

You cash the ace of diamonds, RHO plays the 10.

 

Well?

[bluecalm]

With spades 4-4 there are 3432 layouts with diamonds xx-QT and 3003 layouts with diamonds Qxx-T.

With spades 5-3 there are 3003 layouts with diamonds xx-QT and 2002 layouts with diamonds Qxx-T.

 

That would be it (well almost, we also need to exclude layouts which doesn't lead a spade but those won't change overall result). Now the question is why LHO didn't play 3rd spade having xx+ of hearts, he surely must hope we won't run with 11 tricks now. The source of this hope might be both Qxx of diamonds and xx of diamonds though (partner can have Qxx or maybe A♥). I don't think his play influences our chances enough to change our mind here.

 

I play for drop.

[JLOGIC]

The source of this hope might be both Qxx of diamonds and xx of diamonds though (partner can have Qxx or maybe A♥). I don't think his play influences our chances enough to change our mind here.

 

 

I mean, come on xx of diamonds is feeling way less good about their chances of scoring a D trick than Qxx.

[JLOGIC]

Do we know anything about LHOs style? A queen of an opps suit rarely makes the difference in whether to overcall or not, but this might be a case where one would overcall with AJ9xx Qxx white/white at MP, but not with AJ9xx xx.

 

On the other hand LHO might have AJ32. Damn attitude leads.

 

LHO thinks for quite a long time and plays a highish club.

 

I'm just always hooking the diamond here, but the tank freaks me out.

 

It is impossible to me after spade spade and we pitch a club that someone doesn't cash their spade with xx of diamonds. All we need is running diamonds and the HAK to have the rest of the tricks, which is fairly likely when we pitch a club at trick 2.

 

That said, I would think that most people would not tank that long before playing a club when they held Qxx of diamonds. Maybe our LHO is a good player and realizes that we might hook the diamond with the 9 in dummy (especially if we have Tx, since it becomes restricted choice). Maybe he also realized if he cashed the spade and played a club we would have no chance of getting diamonds right, and he'd still beat us if his partner had the CK. Maybe he then decided that the field would not cash, and that declarers would not hook. I dunno, guess he had a lot to think about so his tank isn't unreasonable.

 

I am still going with "not cashing the spade is a completely impossible play looking at xx of diamonds."

[semeai]

With spades 4-4 there are 3432 layouts with diamonds xx-QT and 3003 layouts with diamonds Qxx-T.

With spades 5-3 there are 3003 layouts with diamonds xx-QT and 2002 layouts with diamonds Qxx-T.

 

AKA an 8:7 ratio in favor of QT when spades 4-4 and a 9:6 ratio in favor when spades 5-3 (ratio of number of vacant spaces for the Queen).

[JLOGIC]

Using math/empty spaces on a hand like this is weird to me

[semeai]

Using math/empty spaces on a hand like this is weird to me

 

I didn't mean to suggest a play; I just don't like large numbers when small ones are at hand. I agree that whatever we think of the likelihood of LHO switching at trick 3 with the two holdings is more important than the prior probabilities.

 

Added: Also, the above vacant spaces (ie including spades) aren't quite right because of the problem that one tends to lead a long suit.

[Phil]

Do we know anything about LHOs style? A queen of an opps suit rarely makes the difference in whether to overcall or not, but this might be a case where one would overcall with AJ9xx Qxx white/white at MP, but not with AJ9xx xx.

 

On the other hand LHO might have AJ32. Damn attitude leads.

 

 

 

I'm just always hooking the diamond here, but the tank freaks me out.

 

It is impossible to me after spade spade and we pitch a club that someone doesn't cash their spade with xx of diamonds. All we need is running diamonds and the HAK to have the rest of the tricks, which is fairly likely when we pitch a club at trick 2.

 

That said, I would think that most people would not tank that long before playing a club when they held Qxx of diamonds. Maybe our LHO is a good player and realizes that we might hook the diamond with the 9 in dummy (especially if we have Tx, since it becomes restricted choice). Maybe he also realized if he cashed the spade and played a club we would have no chance of getting diamonds right, and he'd still beat us if his partner had the CK. Maybe he then decided that the field would not cash, and that declarers would not hook. I dunno, guess he had a lot to think about so his tank isn't unreasonable.

 

I am still going with "not cashing the spade is a completely impossible play looking at xx of diamonds."

 

Reminds me of a certain hand told to me after day 2 of the LMs.

[bluecalm]

I mean, come on xx of diamonds is feeling way less good about their chances of scoring a D trick than Qxx.

 

I play all my bridge vs donks :(

My default is to doubt anybody is going to go beyond: "maybe he doesn't have 11 tricks after all and I am not giving him a free one in spades" with both xx and x of diamonds. I see that it's likely that good player wouldn't play a club with xx of diamonds.

 

Using math/empty spaces on a hand like this is weird to me

 

Why ? It's good to know how often they have certain hand and then use judgement to determine if they play differently from xx-QT than from Qxx-x often enough to sway the decision.

Anyway I take your judgement over mine any day, so now I would hook if faced this decision at the table, especially when prior probabilities are close.

 

AKA an 8:7 ratio in favor of QT

 

I am quite serious: I am yet to grasp empty spaces argument intuitively. It always seems like a gimmick to me and I need to see layouts number to believe it. Thanks for pointing this out :-)

 

Also, the above vacant spaces (ie including spades) aren't quite right because of the problem that one tends to lead a long suit.

 

I pointed that out in my original post, however my intuition is that it won't change math significantly but yeah, this is a good point.

[semeai]

I am quite serious: I am yet to grasp empty spaces argument intuitively. It always seems like a gimmick to me and I need to see layouts number to believe it. Thanks for pointing this out :-)

 

The argument for empty spaces is cute actually:

 

For definiteness, say one hand has 8 empty spaces and one has 7. Take the 15 cards and shuffle them and deal them out, 8 in a row for one player and 7 in a row for the other. It's equally likely the Queen is in any of the 15 slots, so the ratio is 8:7.

 

[The trick is that it's really easy to see if you use the order you deal the cards in. If you use combinations ("a choose b") then the computation is a bit messy and has a bunch of cancellations but comes out the same, of course.]

[bluecalm]

I guess I am not thinking in terms of: "where is the queen" but in terms of "how many hands with the queen on the right are there". Anyway, it's the same thing, let's not derail the thread :)

[JLOGIC]

 

 

 

 

Why ? It's good to know how often they have certain hand and then use judgement to determine if they play differently from xx-QT than from Qxx-x often enough to sway the decision.

Anyway I take your judgement over mine any day, so now I would hook if faced this decision at the table, especially when prior probabilities are close.

 

 

 

It was a pretty dumb or at least inarticulate argument by me lol. At the very least, you know I respect math in bridge/life always. I guess a better way to say it is that I think we should be able to figure out what they have almost always in this type of spot combined with their action so much so that we should ignore whether it is 1.5:1 or 2:1 or w/e based on empty spaces.

 

EG if they insta shifted I would feel like it's 100 % that they had Qxx of diamonds and wouldn't even think about anything else. The tank shift is a judgement call, but my judgement would still be based on how likely they are to do that with xx or Qxx. Of course if you feel like they are equally likely to have either based on their play + tempo you should go with empty spaces, but I feel like that is a cop out and you are not trying enough/not sure enough in your read to act on it. I will note that this is generally how I play bridge but it's because I consider it one of my strengths, so it could be that I am overrating my read or I am just projecting my strengths/weaknesses onto others. I do feel like we should commit based on all of that rather than empty spaces, empty spaces is what we should use without other clues.

 

Anyways, I'm not super confident, like I said the tank throws me off but I still think it's an impossible play to shift with xx of diamonds, but I could be wrong.

[bluecalm]

I feel that many people would be afraid of giving free spade trick/losing an option to take Kc.

Again, my intuition was shaped by playing weak players as I never played significant number of hands against good opponents so it's obviously skewed towards prior percentages/disregarding possibility of them making any advanced reasoning.

[Finch]

Do we know anything about LHOs style? A queen of an opps suit rarely makes the difference in whether to overcall or not, but this might be a case where one would overcall with AJ9xx Qxx white/white at MP, but not with AJ9xx xx.

 

On the other hand LHO might have AJ32. Damn attitude leads.

 

I put the vulnerability in wrong, your opponents are vul and you aren't, so he probably wouldn't overcall either way.

 

We like attitude leads for many reasons, this is one of them (i was your RHO).

 

You and your LHO were, many years ago, a WBF & EBL junior gold-medal winning partnership.

[bluecalm]

Now when we know LHO and RHO are good, is it possible that LHO would realize that playing a club with Qxx of diamonds is suicide because we are going to hook having Tx/Jx so they wouldn't play a club holding Qxx of diamonds ?