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What's My Line

#1 User is offline   lamford 

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Posted 2020-October-20, 07:24


Matchpoints. Lead A

An intermediate player went off as West here, so this is your chance to be advanced by playing the right line. North leads two top hearts and South discards the nine of clubs, encouraging, on the second heart. North now leads the five of hearts. Over to you.
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#2 User is offline   Cyberyeti 

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Posted 2020-October-20, 08:53

Do NS have an opening bid for 55 minors weak ? My first thought looks intergalactically stupid if S is 1156 but if they'd open that with a 2 suited bid, or are likely to open 3 in first I'd feel a bit safer.
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#3 User is offline   mikeh 

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Posted 2020-October-20, 10:58

Match points can make us do silly things (they’d be ‘great’ things if they worked), such as ruff with the Ace, hook a spade, cross in clubs, hook again, run the spades, catching north in a pop-up squeeze if he began with the diamond Queen. making 5 for a lot of mps😀

I’m not saying that’s my line. I do know how I’d play it, but I’ll let others take a shot before commenting further (including whether I’d take the line I just outlined)
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#4 User is offline   lamford 

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Posted 2020-October-20, 11:04

View PostCyberyeti, on 2020-October-20, 08:53, said:

Do NS have an opening bid for 55 minors weak ? My first thought looks intergalactically stupid if S is 1156 but if they'd open that with a 2 suited bid, or are likely to open 3 in first I'd feel a bit safer.

No, they just play Acol with a weak NT and are intermediate players. I think they would usually have seven for a three-level pre-empt.
I prefer to give the lawmakers credit for stating things for a reason - barmar
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#5 User is offline   Cyberyeti 

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Posted 2020-October-20, 12:22

I think I'd just settle for the best chance of making 4, the contract and lead look normal even if the auction might not be. My first thought was to discard a club on the heart, and subsequently I can pitch my second club on the diamonds and ruff the final heart if S started with 2-3 spades, if he started with 4 I need aprobably against the odds diamond finesse. I pay off to S being 1156 or holding all 7 diamonds and choosing not to open, but I think in the latter case unless S's singleton heart was the 8, I'd expect N to have returned the 8 if he wanted a diamond ruff.
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#6 User is offline   lamford 

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Posted 2020-October-20, 17:48

View PostCyberyeti, on 2020-October-20, 12:22, said:

I think I'd just settle for the best chance of making 4, the contract and lead look normal even if the auction might not be. My first thought was to discard a club on the heart, and subsequently I can pitch my second club on the diamonds and ruff the final heart if S started with 2-3 spades, if he started with 4 I need aprobably against the odds diamond finesse. I pay off to S being 1156 or holding all 7 diamonds and choosing not to open, but I think in the latter case unless S's singleton heart was the 8, I'd expect N to have returned the 8 if he wanted a diamond ruff.

South's heart was the eight, but you are right that he would have opened 3D with seven of them. I think the five of hearts had no real significance and you are missing a simple line, almost 100%.
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#7 User is offline   pilowsky 

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Posted 2020-October-21, 01:25

Discard a Club from dummy, South is end played. if South ruffs contract makes with diamond finesse. If not 9 of hearts is top.
That's my guess.
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#8 User is offline   AL78 

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Posted 2020-October-21, 05:33

View Postpilowsky, on 2020-October-21, 01:25, said:

Discard a Club from dummy, South is end played. if South ruffs contract makes with diamond finesse. If not 9 of hearts is top.
That's my guess.


I don't follow. If South ruffs, they can get off lead with a club, I don't see an endplay. If South ruffs, you need the rest, which means picking up the spade and diamond queen. How do you know for certain the diamond finesse is working, which you need to throw both the heart and club losers? You don't know for certain the spade layout, although South holding Qxx is what I'd play for.
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#9 User is offline   pilowsky 

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Posted 2020-October-21, 06:08

View PostAL78, on 2020-October-21, 05:33, said:

I don't follow. If South ruffs, they can get off lead with a club, I don't see an endplay. If South ruffs, you need the rest, which means picking up the spade and diamond queen. How do you know for certain the diamond finesse is working, which you need to throw both the heart and club losers? You don't know for certain the spade layout, although South holding Qxx is what I'd play for.


You're right. I don't know for sure.. Let's put it this way. If guessing is on a scale of 0-100, where certainty is 0 and 100 is absolute bloody lunacy, then saying "that's my guess" is probably being a bit mild.
Perhaps I should say "that's my stab in the dark". How's that?

The 0-100 method was taught to me by a Japanese post-doc. Apparently, that's how they get taught English in Japan. So you can give my estimate a 25% on the Miyawaki scale of inverse likelihood (guesswork).
Or, to put it another way, no, I wouldn't put much store in what I say either.
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#10 User is offline   Cyberyeti 

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Posted 2020-October-21, 06:46

View Postlamford, on 2020-October-20, 17:48, said:

South's heart was the eight, but you are right that he would have opened 3D with seven of them. I think the five of hearts had no real significance and you are missing a simple line, almost 100%.


I thought I could see a way all the lines fail to the wrong holdings.

The 4 lines in no particular order (with possible insertion of cashing diamonds) are:

Ruff high and finesse
Ruff high and play K
Ruff low
Discard

The last 2 lose trivially to a 1156 hand in practice (the way of playing the spades can't cope with both Qx/Qxx N and Qxxx S)
The first loses trivially to stiff Q or Qx with N and a 4th heart, and if you cash the diamonds first, disposing of a heart, a club return kills any squeeze if the club honours are split
The second seems to lose to Qx with N

There is a ruffing squeeze of sorts but it appears to me N can break it up by leading the correct minor when winning Q.
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#11 User is offline   lamford 

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Posted 2020-October-21, 08:15

View PostCyberyeti, on 2020-October-21, 06:46, said:

I thought I could see a way all the lines fail to the wrong holdings.

The 4 lines in no particular order (with possible insertion of cashing diamonds) are:

Ruff high and finesse
Ruff high and play K
Ruff low
Discard

The last 2 lose trivially to a 1156 hand in practice (the way of playing the spades can't cope with both Qx/Qxx N and Qxxx S)
The first loses trivially to stiff Q or Qx with N and a 4th heart, and if you cash the diamonds first, disposing of a heart, a club return kills any squeeze if the club honours are split
The second seems to lose to Qx with N

There is a ruffing squeeze of sorts but it appears to me N can break it up by leading the correct minor when winning Q.

Yes, mea culpa. You are right that only a self-kibitzer has a 100% line. I agree that you have to pay off to 1-1-(65). I think the right line is to ruff low. Say South overruffs and plays the king of clubs. You win in dummy, cash the ace of spades, but nothing happens. Now you cash the ace, king of diamonds, throwing a club. Now you ruff a club and ruff the last heart with the six of spades, not caring who has the queen of spades.
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#12 User is offline   Cyberyeti 

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Posted 2020-October-21, 08:58

View Postlamford, on 2020-October-21, 08:15, said:

Yes, mea culpa. You are right that only a self-kibitzer has a 100% line. I agree that you have to pay off to 1-1-(65). I think the right line is to ruff low. Say South overruffs and plays the king of clubs. You win in dummy, cash the ace of spades, but nothing happens. Now you cash the ace, king of diamonds, throwing a club. Now you ruff a club and ruff the last heart with the six of spades, not caring who has the queen of spades.


Well if S has it he overruffs you again for -1.
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#13 User is offline   Huibertus 

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Posted 2020-October-21, 10:09

View Postmikeh, on 2020-October-20, 10:58, said:

Match points can make us do silly things (they’d be ‘great’ things if they worked), such as ruff with the Ace, hook a spade, cross in clubs, hook again, run the spades, catching north in a pop-up squeeze if he began with the diamond Queen. making 5 for a lot of mps😀

I’m not saying that’s my line. I do know how I’d play it, but I’ll let others take a shot before commenting further (including whether I’d take the line I just outlined)


Given it indeed is matchpoint, I don't think this line is silly at all!

But yes, for those that mostly play for imps (myself included) it feels odd. Come to think of it, I think this is the percentage play in Matchpoints, which is what that game is all about... Surely you have a better chance then 50% of outscoring the Imps-safe play, so it'll pay off in the long run.
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#14 User is offline   lamford 

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Posted 2020-October-21, 10:13

View PostCyberyeti, on 2020-October-21, 08:58, said:

Well if S has it he overruffs you again for -1.

Indeed. I think now that you always have to guess who has the queen of spades. Not a good problem.

I am not sure now what the right line is.
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#15 User is offline   Cyberyeti 

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Posted 2020-October-21, 10:22

View Postlamford, on 2020-October-21, 10:13, said:

Indeed. I think now that you always have to guess who has the queen of spades. Not a good problem.

I am not sure now what the right line is.


In some ways it's an interesting problem precisely because it has no perfect solution
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#16 User is offline   miamijd 

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Posted 2020-October-21, 10:35

It's not likely that South is 1156. Possible, sure, but since the H are 6/1, South is much more likely to be long in spades than North. There are thus two lines that are worth consideration:

1. The one Mikeh suggested. If South has the Qs, this makes 5 if North has the Qd and 4 otherwise. It loses when North has the Qs.

2. Discard from dummy and let South ruff. Win the club return and play the As from dummy. If both follow, you draw trump, pitch the club on a diamond and ruff the last heart. If South started with four trump, you hook the spade and run trump, hoping that North had the Qd (he'll be caught in the same show-up squeeze at the end). This never makes 5. It makes 4 unless South is 1156 or 41 in the majors with the Qd.

So the cases are:
A. North has a spade void: Line 1 makes 5 if North has the Qd and 4 otherwise. Line 2 makes 4 if N has the Qd or is -1 otherwise.

B. North has a small stiff spade: Line 1 makes 5 if North has the Qd and 4 otherwise. Line 2 makes 4.

C. North has the stiff Qs or Qx of spades: Line 1 goes down. Line 2 makes 4.

The two lines are pretty close in expected tricks, but there is a key determining factor. Line 2 makes the contract a lot more often. In a normal so-so field, not everyone will be in game. Many won't open the West hand 2S, and if you don't, getting to game isn't 100%. Thus, I would go with Line 2, as the expected MPs here will be higher (you will almost always beat those who aren't in game).

Cheers,
Mike
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#17 User is offline   Douglas43 

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Posted 2020-October-22, 09:22

I agree with miamijd's decision. The only thing I would add to miamijd's analysis is an extra option in his (B)

B. North has a small stiff spade: Line 1 makes 5 if North has the Qd and 4 otherwise. Line 2 makes 4. [Same applies where North has two small Spades, I think].

That suggests on 3-1 breaks with North holding the singleton, line 1 (ruff high and finesse) scores the same or better three times (bare 7, 6 or 3) and worse than line 2 (discard) once (bare Q).

On 2-2 breaks, line 1 scores the same or better three times (North has 76, 73, 63) and worse than line 2 three times (North has Q7, Q6, Q3)

When North has 6 hearts and 2 spades, there are only 5 spaces for QD in North's hands versus 10 spaces in South's hand, so Line 1 should gain on only a third of the "same or better" hands. For 6 hearts and 1 spade, the vacant spaces are 6 versus 9.

If that is right that on North's singletons ruffing high is better on 1/4, worse on 1/4, same on 1/2
On North's doubletons, ruffing high is better on 3/6 x 6/15= 20%, same on 3/6 x 9/15= 30%, and worse on 3/6=50%. Hence, discarding seems to gain slightly more often

That is in addition miamijd's important point about the value of making your game

[BTW, thanks for the topic, when I saw it I thought of the ruff high and finesse line, underestimating the value of discarding to force South to shorten their trumps]
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#18 User is offline   miamijd 

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Posted 2020-October-22, 13:23

Almost - not quite. You are analyzing the hand only in terms of the "vacant places" principle. But if South has the Qs, then North has to have a decent bit of stuff beyond the AKxxxx of H for his 3H overcall. Yes, KQ of clubs would do it, but remember South threw the 9c (encouraging) at trick 2. Since dummy has the Ace, that would seem to suggest the K. If you give South the Kc, then it becomes more of a tossup as to where the Qd is.

Cheers,
Mike
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