BBO Discussion Forums: Calling all math freaks - BBO Discussion Forums

Jump to content

  • 2 Pages +
  • 1
  • 2
  • You cannot start a new topic
  • You cannot reply to this topic

Calling all math freaks

#21 User is offline   phil_20686 

  • Scotland
  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,754
  • Joined: 2008-August-22
  • Gender:Male
  • Location:Scotland

Posted 2011-November-25, 06:14

View Postrhm, on 2011-November-25, 04:52, said:

Unless you specify a line of play precisely and explain what you will do under the various circumstances, nobody can check your calculations. Saying you start with a low club to dummy at trick 2 is not a line.
Double dummy I do not doubt that you can take advantage of all possible layouts, but in single dummy squeeze play in particular you often can not cater for that, because squeeze play usually requires a precise sequence of plays depending on the actual layout of the opponents cards and often you have to weaken your entry positions before knowing that.
I am not convinced yet that playing on clubs first is better, though it could induce a defensive error if LHO has the king and to assume you will get your club guess right is not a fair comparison.

Rainer Herrmann


Ok, thought we had basically specified these two lines above:

line A is play a club, if it "wins", cash clubs spades and three diamonds ending in dummy pitching one heart. Then we have an automatic squeeze against anyone with four hearts and either the remaining club honour, or four hearts and the long diamonds.

If the club loses, say they return a club (makes no difference), then I again cash the clubs diamonds and spades ending in dummy (no pitch needed as no club winner now). If somone holds all three guards they are automatically squeezed - no guessing needed (case 3). If the long diamond is good I can play that and pitch a heart, now there will be an automatic club-heart squeeze - no guessing needed (case 2). If nothing works out I can just try cashing the hearts. (case (1)).

Line B- play a heart, if they are 3-3 we are good (case (1)). (i didnt look at overtricks). If they are 4-2, play a 4th heart, pitching a club. Assume a passive return, if rho returns a club win the ace assuming they are not letting you play the clubs to advantage. At this point cash you winners ending in hand and playing the fifth heart last, this will catch lho in a positional squeeze if he has the KC and long diamonds (case 2).

If hearts are 5-1, play a club up, suppose a diamond or a spade or a club is returned (a heart just means you pitch a spade from dummy and managed entries a little more carefully), so now cash your two winning clubs, 3 spades and two diamonds ending in dummy. When you play the last heart you will catch either 5h and 4d together in an automatic squeeze (i missed this one, will edit above), of lho in a positional squeeze if he has long clubs and long diamonds (you pitch the club from dummy on the last heart winner). This turns up cases 3,4, and 5. Again, no guessing is needed in this line.

If hearts are 6-0 it might appear that you have more options than above in terms of squeezes, but they all go away if the person who wins the club can play a heart themselves, and we are getting into sub one percent gains here so I just ignored these.
The physics is theoretical, but the fun is real. - Sheldon Cooper
0

#22 User is offline   phil_20686 

  • Scotland
  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,754
  • Joined: 2008-August-22
  • Gender:Male
  • Location:Scotland

Posted 2011-November-25, 06:19

View Postwhereagles, on 2011-November-25, 03:00, said:

As I said, LHO is capable of ducking. But if you do that at trick 2, I'm not sure he will. Say he will duck like 25% of the cases.

Phil_20686: thx I'll have a look.


Even ignoring that, its better than 50% because Kx in the slot cannot escape, so you win all J onside and Kx onside, and stiff K or J. Its not much, but its something.
The physics is theoretical, but the fun is real. - Sheldon Cooper
0

#23 User is offline   gnasher 

  • Andy Bowles
  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 11,993
  • Joined: 2007-May-03
  • Gender:Male
  • Location:London, UK

Posted 2011-November-25, 07:31

View Postphil_20686, on 2011-November-25, 06:14, said:

line A is play a club, if it "wins", cash clubs spades and three diamonds ending in dummy pitching one heart. Then we have an automatic squeeze against anyone with four hearts and either the remaining club honour, or four hearts and the long diamonds.

That's what you'd do if you'd played a club to the 10 and it had lost to the king, or if LHO had risen with K.

If you'd played a club to the queen and it had won, you'd be in even better shape: cash two top hearts, claiming if they're 4-2 or better. If hearts are 5-1, duck a heart and hope for a diamond-something squeeze.

If LHO has Kxxx, he can't afford to rise with K, so against a good defender we should plan to play Q.
... 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
0

#24 User is offline   AlexJonson 

  • PipPipPipPip
  • Group: Full Members
  • Posts: 496
  • Joined: 2010-November-03

Posted 2011-November-25, 10:17

View Postwhereagles, on 2011-November-25, 03:00, said:

As I said, LHO is capable of ducking. But if you do that at trick 2, I'm not sure he will. Say he will duck like 25% of the cases.
...


If you are fairly sure that LHO will rise with the King holding Kx, KJ,and probably with Kxx,KJxx(xx) - ducking only with Kxxx(xx), and KJx then it's clear that when the King doesn't appear from LHO, you should play the ten of clubs, because you are now more likely to find LHO with the Jack than the King.

This way your success in 'guessing' clubs is about 62% - with LHO ducking in 35% of cases where LHO has the King. But you will lose a trick in clubs except when LHO holds KJX. The remaining calculations have been done by phil_20686.

On the other hand, if you believe that this position is generic enough for LHO to avoid exploitation by ducking when he holds anything other than K singleton or KJ doubleton, you are probably better to play the club Queen when the King doesn't appear, and again phil_20686 calculations apply (as modified by Gnasher's point).
0

#25 User is offline   nige1 

  • 5-level belongs to me
  • PipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 9,128
  • Joined: 2004-August-30
  • Gender:Male
  • Location:Glasgow Scotland
  • Interests:Poems Computers

Posted 2011-November-28, 20:14


whereagles asks "South to play 6NT on the 10 of diamonds lead?"

Third thoughts: Q, QK. Then...
- If are 5-1 or 6-0 then try A and another.
- If RHO has 4 then concede a and play for a minor-suit squeeze,
- If LHO has 4 then adopt rhm's line: cash and if RHO has 4+, try to endplay LHO.

0

#26 User is offline   aguahombre 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 12,029
  • Joined: 2009-February-21
  • Gender:Male
  • Location:St. George, UT

Posted 2011-November-28, 20:17

ace and another club, rather than low away from ace seems to reduce later options and risk going down right then and there.
"Bidding Spades to show spades can work well." (Kenberg)
0

#27 User is offline   phil_20686 

  • Scotland
  • PipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 2,754
  • Joined: 2008-August-22
  • Gender:Male
  • Location:Scotland

Posted 2011-November-29, 07:27

do we know what the whole hand was?
The physics is theoretical, but the fun is real. - Sheldon Cooper
0

#28 User is offline   whereagles 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 14,900
  • Joined: 2004-May-11
  • Gender:Male
  • Location:Portugal
  • Interests:Everything!

Posted 2011-November-29, 08:29

Out of my head it was something like this (spots not 100% accurate)

2NT = 18-20 and 3NT = 5 hearts. West leads 10 of diamonds


The club up line would have worked, provided you guess right. Whether or not West would duck smoothly, we'll never know. If you guess right or LHO plays the king you're home on the hearts or a red squeeze. If you guess wrong you're probably down, as hearts lie 4-2 and no progressive squeeze develops.

Most of the field tried 4 rounds of hearts, relying on a good red break or subsequent minor-suit squeeze. That was not to be and all ended 1 down.

Still, my interest is in what's the best line in theory (if such thing even exists lol).
0

#29 User is offline   jogs 

  • PipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 1,316
  • Joined: 2011-March-01
  • Gender:Male
  • Interests:student of the game

Posted 2011-November-29, 14:47

View Postaguahombre, on 2011-November-28, 20:17, said:

ace and another club, rather than low away from ace seems to reduce later options and risk going down right then and there.


Don't like it. Makes it too easy for LHO to duck the club king.
0

#30 User is offline   aguahombre 

  • PipPipPipPipPipPipPipPipPipPip
  • Group: Advanced Members
  • Posts: 12,029
  • Joined: 2009-February-21
  • Gender:Male
  • Location:St. George, UT

Posted 2011-November-29, 19:03

View Postjogs, on 2011-November-29, 14:47, said:

Don't like it. Makes it too easy for LHO to duck the club king.

I am planning to play the queen. works when he has the king, and I can just play for 4-2 hearts, or when he has doubleton jack of clubs and either red suit behaves.

What does lefty do with 3-4-4-(JX), or 2-4-4-(JXX), in addition to the times he holds the club king, plus those possibilities? Winning Diamond ace and leading low club from Ace at trick two feels good.
"Bidding Spades to show spades can work well." (Kenberg)
0

  • 2 Pages +
  • 1
  • 2
  • You cannot start a new topic
  • You cannot reply to this topic

11 User(s) are reading this topic
0 members, 11 guests, 0 anonymous users