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Perhaps not similar

#1 User is offline   Phil 

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Posted 2011-July-12, 21:03

I've seen two interesting play problems the past several days.

1.


Opening lead is the 5, 6, J?. Win or duck?

2.


The 6 hits the table. Over to you.
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#2 User is offline   cloa513 

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Posted 2011-July-12, 21:43

View PostPhil, on 2011-July-12, 21:03, said:

I've seen two interesting play problems the past several days.

1.


Opening lead is the 5, 6, J?. Win or duck?

2.


The 6 hits the table. Over to you.

I see no choice on 1 but to duck and hope it was from four card diamonds and that LHO doesn't have enough entries and/or RHO doesn't have enough trumps to cause you trouble.

A hopefully RHO has Hx is therefore blocked or hearts are 4-4 and the club finesse works or you judge that K drops.
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#3 User is offline   gnasher 

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Posted 2011-July-13, 02:07

Assuming that the defenders have led normally:

On the first one, taking the ace works if LHO has led a singleton holding both aces. Ducking works when he's led a doubleton with both aces. I think the second is more likely, so I duck.

On the second one, assuming that the club finesse is going to lose:
- Taking the ace works only if RHO has HT with A. (If LHO has A, blocking the heart suit doesn't work; if RHO has A he can unblock from H9.)
- Playing low works when RHO has HT with A, and also:
   * H9 with A
   * T95 / T94 / T9 / T75 / T74 / T7 with RHO leading low from KQ9xx(x) or KQ7xx(x).
   * 975 / 974 / 97 with RHO leading low from KQTxx(x)
So I play low.

This post has been edited by gnasher: 2011-July-13, 02:18

... 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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#4 User is offline   CSGibson 

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Posted 2011-July-13, 08:27

1.) With KQJx, RHO might have doubled 2, while he was less likely to do so with KQJ. I duck the first trick.

2.) Duck again. Underlead of KQ is more likely to me than lefty having a 6 card heart suit that A. he never mentioned and B. that blocks when I play the ace.
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#5 User is offline   Phil 

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Posted 2011-July-13, 09:28

I'll take #2 1st. I ducked while the declarer at the other table (with no extraneous information) won the Ace. LHO held xx K9x6xx, xx, Kxx. Lose 11.

#1 seems more interesting. I kibbed this in a JEC match and Alfredo played 4. It was about 2:00 AM his time (I'm assuming he was home), and it was near the end of the match. He opened this 1 initially, and then asked for an undo back to 1N, so he was evidently tired.

He ducked the opening lead in less time it takes for me to write this. That was the winning play as his LHO held both round aces and a doubleton diamond.

While 5-2 doubleton is more likely than a singleton 5, you also have to assume that both aces are with LHO. Yet, a singleton lead is almost always more attractive than a doubleton, so this mitigates the doubleton vs singleton ratio. However, a doubleton lead is much more attractive when LHO has a sure trump entry, and we have to assume he does. I also think Chris' inference about RHO failing to double the transfer is valid as well.

Did RHO misplay? It seems playing the Q (the card he is known to hold) might have steered declarer wrong. If the lead was from KJ52, then declarer's only real chance is to win the diamond, and hope his RHO has both aces. Its hard to see how this falsecard can deceive partner.
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#6 User is offline   han 

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Posted 2011-July-13, 09:45

Ducking seems mostly right on 1 because, as CSGibson said, RHO might have doubled with KQJx.

Phil I agree that playing the queen looks like the correct techical play, but wouldn't it actually make it easier? If LHO has KJx then you have to duck, and if LHO has KJxx then your only chance is that RHO has both aces, and you still make after a duck.
Please note: I am interested in boring, bog standard, 2/1.

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#7 User is offline   han 

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Posted 2011-July-13, 09:59

View Postgnasher, on 2011-July-13, 02:07, said:

On the second one, assuming that the club finesse is going to lose:
- Taking the ace works only if RHO has HT with A. (If LHO has A, blocking the heart suit doesn't work; if RHO has A he can unblock from H9.)


I know your opponents are all world class, and I'm sure they would all pitch the heart king at trick 1. But would all of your LHOs know to switch to diamonds after winning the club king? Most of my opponents would probably give count at trick 2 and LHO would have a complete guess. In the US some might play smith and they would still have a guess. Meckwell would play reverse suit preference and they might still have a guess if you play the 7 on the first round of clubs. If your opponents play standard suit preference, well, those opponents are just too tough!

Quote

- Playing low works when RHO has HT with ♦A, and also:
* H9 with ♦A


Why does it matter who has the diamond ace, don't you finesse in clubs anyway? So if you duck and RHO wins the heart and fires back a heart, you always lose if the club finesse is off. It seems to me that ducking is only better than playing the ace when LHO has underlead the KQ. If the 6 is fourth best then RHO holding H10 (or a defensive mistake) seems more likely than LHO having the KQ.
Please note: I am interested in boring, bog standard, 2/1.

- hrothgar
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#8 User is offline   han 

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Posted 2011-July-13, 09:59

Nice problems btw Phil!
Please note: I am interested in boring, bog standard, 2/1.

- hrothgar
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#9 User is offline   gnasher 

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Posted 2011-July-13, 10:14

View Posthan, on 2011-July-13, 09:59, said:

I know your opponents are all world class, and I'm sure they would all pitch the heart king at trick 1. But would all of your LHOs know to switch to diamonds after winning the club king? Most of my opponents would probably give count at trick 2 and LHO would have a complete guess. In the US some might play smith and they would still have a guess. Meckwell would play reverse suit preference and they might still have a guess if you play the 7 on the first round of clubs. If your opponents play standard suit preference, well, those opponents are just too tough!

Some of my LHOs would duck the first club from Kxx, then get a discard from partner. Ducking from Kx to get the second half of a Smith signal is probably only a theoretical possibility.

Quote

Why does it matter who has the diamond ace, don't you finesse in clubs anyway? So if you duck and RHO wins the heart and fires back a heart, you always lose if the club finesse is off. It seems to me that ducking is only better than playing the ace when LHO has underlead the KQ. If the 6 is fourth best then RHO holding H10 (or a defensive mistake) seems more likely than LHO having the KQ.

Sorry, yes you're right.

This post has been edited by gnasher: 2011-July-13, 10:18

... 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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#10 User is offline   han 

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Posted 2011-July-14, 02:37

View Postgnasher, on 2011-July-13, 10:14, said:

Some of my LHOs would duck the first club from Kxx, then get a discard from partner.


Absolutely. I'm just saying that on some of the hands where they can beat it on perfect defense, they will have a guess and sometimes go wrong. Of course the worse your opponents are, the more often you will make it. In practice against most opponents this seems a substantial edge in favor of playing the ace.
Please note: I am interested in boring, bog standard, 2/1.

- hrothgar
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#11 User is offline   JLOGIC 

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Posted 2011-July-14, 04:06

View Posthan, on 2011-July-14, 02:37, said:

Absolutely. I'm just saying that on some of the hands where they can beat it on perfect defense, they will have a guess and sometimes go wrong. Of course the worse your opponents are, the more often you will make it. In practice against most opponents this seems a substantial edge in favor of playing the ace.


With the same logic, vs most opps I would just play for them to have led a stiff D on hand 1. Obv a good opp will be more likely to lead from a doubleton with the trump ace. I think weaker opps will not always know this and thus will lead from a stiff diamond 100 % of the time and from a doubleton diamond a much smaller % of the time when they hold those holdings. How fast they led a diamond would also impact my decision.
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