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How bad is this line of play?

#1 User is offline   1eyedjack 

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Posted 2015-July-01, 00:29


MP, Instant robot tournament, robot version 34

The line only scored 3% of the MPs, but is it just resulting to use that as a guide?

Obviously the line would be appalling at IMP.

My thoughts were that if Spades were 3-3 I have 13. If they are 5-1 I find out before losing my stopper, so I start with 3 rounds of Spades. Bad news.

Now I can certainly make by giving up a Spade. But I still have chances of 13 if the D:Q drops in two rounds (or singleton on my right). Furthermore, 12 tricks is still available if the Q does not drop provided that the Diamond length is with the Spade shortage, which is better than even odds.

Anyway, those were my thoughts. What say you? (I think I should have thrown a Club rather than Diamond on third round of Spades, but gloss over that for this purpose)
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

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#2 User is offline   rhm 

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Posted 2015-July-01, 01:56

The following comments:

Decision point is after 3 rounds of spades and one round of diamonds.
At that point the chance of a singleton diamond queen has been tested and failed.
Chances that the queen will drop doubleton now is less that 30%
Chances that length in spades and diamond will be in the same hand may be less than even but is significantly higher than 30%.
So at decision point your chances going down in 6NT by your line of play after some chances for 13 tricks have already been exhausted is higher than making an overtrick.
So you should give up a spade, before playing your second diamond.

Note that the lead was stupid and has given you a trick.
Without that even a 3-3 spade break does only provide 12 certain tricks.
Even if all West robots will make this stupid lead some will play either a different contract or from the North hand.
All tables without a heart lead from West will go after diamonds without testing spades first.

Therefor I think testing the spades is a subtle error.
It is better to test the diamonds not to fall behind those declarers who did not receive a heart lead from West in case the queen drops.

As the play went up to the decision point it is likely that West has at least 5 cards in hearts, because he discarded a heart on the third spade and that would be strange on the bidding from QT92.
Given this inference we know at decision point as many major suit cards from East as from West and it is probably even who holds more cards in diamonds and the actual layout is not unlikely.
You could have made your contract after the second diamond by cashing your remaining heart.
This triple squeezes East, though the triple squeeze gains only one trick.

Rainer Herrmann
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#3 User is offline   1eyedjack 

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Posted 2015-July-01, 02:31

Ah, thanks for that.

One factor that I also significantly misjudged was the number of pairs playing in 6N, which does seem to be the top spot, lead notwithstanding. Only a little under half the room were in it, which if I knew that would argue for an IMP-style play strategy.
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

Psyche (pron. sahy-kee): The human soul, spirit or mind (derived, personification thereof, beloved of Eros, Greek myth).
Masterminding (pron. mPosted ImagesPosted ImagetPosted Imager-mPosted ImagendPosted Imageing) tr. v. - Any bid made by bridge player with which partner disagrees.

"Gentlemen, when the barrage lifts." 9th battalion, King's own Yorkshire light infantry,
2000 years earlier: "morituri te salutant"

"I will be with you, whatever". Blair to Bush, precursor to invasion of Iraq
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#4 User is offline   gszes 

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Posted 2015-July-01, 10:10

Look at your contract. 6N has to seem like the top spot (I would have bid 7 knowing p was around a 3/1 favorite to hold the spade J). Once you have made that determination playing "safe" is not a bad thing. We use safety plays at IMPS all the time because going down in an otherwise makeable contract can be disastrous. The downside of trying for 7 is that it puts the top ranked spot at risk for little to no reason. You got a favorable lead without which you would still have to scramble for 12 tricks. RHM covered the play aspect I wanted to put in perspective WHY worrying about 7 was missing the point.
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#5 User is offline   neilkaz 

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Posted 2015-July-01, 10:48

Is the west bot capable of false carding here from Jxx by dropping the J on trick 2?

If GIB isn't capable of false carding here you then give up on trying for a 33 split and play on .

Re: GIB bidding, why the quant invite with 14-16 opposite 20-21? Isn't that a bit too low of a range to invite a grand?
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#6 User is offline   nige1 

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Posted 2015-July-01, 12:47

View Post1eyedjack, on 2015-July-01, 00:29, said:

MP, Instant robot tournament, robot version 34The line only scored 3% of the MPs, but is it just resulting to use that as a guide?Obviously the line would be appalling at IMP.My thoughts were that if Spades were 3-3 I have 13. If they are 5-1 I find out before losing my stopper, so I start with 3 rounds of Spades. Bad news.Now I can certainly make by giving up a Spade. But I still have chances of 13 if the D:Q drops in two rounds (or singleton on my right). Furthermore, 12 tricks is still available if the Q does not drop provided that the Diamond length is with the Spade shortage, which is better than even odds.Anyway, those were my thoughts. What say you? (I think I should have thrown a Club rather than Diamond on third round of Spades, but gloss over that for this purpose)
After winning J and cashing A (in case there is a singleton J), you might invest your good fortune in a safety play to guarantee your contract against bad breaks: Cash A. Cross to dummy with A. Then lead a covering RHO's card unless he shows out.
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#7 User is offline   billw55 

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Posted 2015-July-01, 13:46

You got a freebie on opening lead against a slam that could go down otherwise. Also you are in the best possible contract at matchpoints. Not a situation to worry much about overtricks. I would take the sure 12.
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#8 User is offline   PhantomSac 

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Posted 2015-July-01, 16:23

Rainer touched on the endgame but it has some highly instructive points.

For starters, Rainer says LHO probably does not have only 4 hearts since they pitched a heart. That is not really true, as with 2434 they were squeezed on the spade and would probably be forced to pitch a heart. However, that is the main gain of cashing the heart, you make on any club layout in that case (cash the heart pitching a club and play a diamond).

You were probably trying to endplay LHO if they had the CJ, however consider this position:



Say that you erroneously exited a diamond without cashing a heart. It seems like you are OK since LHO is endplayed, except he can exit the JACK of clubs. Now you will be forced to lose a club or a spade in the endgame since your tricks are tangled up. So the endplay does not really work.

Let's say LHO has 2533. If RHO has the CJ you are dead, and if LHO has the CJ it looks like he can do the same trick of exiting the jack of clubs right?



Well no, actually the CJ does not work here. After winning in dummy, you cash the diamond and RHO is squeezed in the blacks (if they pitch a spade, club to your ten claim and if they pitch the club run the clubs).

So your line wins when LHO has specifically 2533 with the CJ. That is much less likely than LHO being 2434. Also, cashing the HK always wins on any club layout when LHO is 2623, RHO is just triple squeezed. But you have to make sure to pitch a DIAMOND not a club this time.

Interesting is if you are going to play LHO for 2533, another possible line is to cash the heart king and pitch the diamond, and exit with a spade. This endplays RHO while setting up your spade, who is more likely to have the CJ since they have 4 clubs. Except...



By now you probably guessed it. RHO exits the jack of clubs and your communications are too messed up.

I think that the right line in the endgame is to cash your heart pitching a club and exit a diamond, which would fail. I also don't think you have any reason to believe LHO has the HQ, usually especially gibs do not lead from queens, T9xx is a perfectly normal lead and it's perfectly normal for RHO to duck with Qxxx since they don't know if their partner has T9x or not. Your line was extremely bad though, the other line should be to cash a heart pitching a diamond.
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#9 User is offline   PhantomSac 

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Posted 2015-July-01, 16:34

Another thing that just occurred to me that is interesting, if you cash the HK and they don't play the 9, they cannot have T9xx anymore. They also probably do not have T9xxx since RHO would put up the queen with Qxx. So one possible play is if you play the HK and they play the 9, play them for 2434 and pitch a club, but if they do not remember to play the 9, then go for 2623 and pitch a diamond. Another good example of playing the card you're known to hold reaping rewards. Ofc this depends on how often you think they play the 9 from Q9x remaining.
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