Calling all math freaks

[whereagles]

Hi all, I need some numbers here. Come and help me out :)

 

[hv=pc=n&s=sa75hak642da52ca5&n=skq3hq3dkq74cqt62]133|200|South to play 6NT on the 10 of diamonds lead.[/hv]

 

No inference can be drawn from auction or lead (except that RHO has the ♦J lol). I can basically see two lines:

 

1) play a club up and guess right. If it holds, you're in great shape. If not, you're ok with hearts 3-3.

 

2) play 4 rounds of hearts. If it goes wrong, then win with diamonds 3-3 or a minor suit squeeze vs LHO.

 

What's best? Thx!

[aguahombre]

I guess third hand didn't play his stiff jack at trick one, or you wouldn't be posting.

 

:rolleyes:

[phil_20686]

Even if you guess wrong, in clubs you are in reasonable shape, as you still have 3+3+3+1, and if hearts come in thats enough, or if diamonds come in there is an extra chance of a heart-club squeeze, or if diamonds and hearts and clubs go wrong, you will still make if they are all in the same hand on a progressive squeeze with an extended menaace - if he unguards clubs or diamonds on the third spade you can cash a winner to squeeze them again.

 

Play a club - never pass up the chance for a progressive triple squeeze - they are tooo pretty. :)

 

Also on line B when they win the 4th heart they can put you to the guess in clubs before you test the diamonds.

[dave_w]

It's complicated by the fact that if you play a club up and they play low they probably don't have the King. So I'd always try the Ten (which is very unlikely to hold the trick - hopefully it loses to the King!).

 

And before number crunching what about line 4:

play 3 rounds of Hearts and if LHO has 4 (such that a diamond/club squeeze isn't very likely against LHO anymore) then play a club to the Ten and play for diamonds 3-3 or a squeeze (which might be an unlikely Diamond-Heart squeeze).

[Mbodell]

I'm definitely playing hearts first. If I have 5 tricks, great, play for squeeze for 13. If it splits 4-2, I think I want to lose a heart and try the squeeze rather than play on clubs, even if hearts were 4=2. Playing a club to the ten after 4=2 pretty much requires LHO to have the J and RHO to have the K (otherwise lefty wins it and cashes a heart), and even if that happens it only gets me to 11 tricks (3♠, 3♥, 3♦, 2♣). If diamonds were 3-3 the squeeze line picks that up for 3+4+4+1=12 tricks. So pretty much you are banking on LHO having 4♦ to go with 4♥ and the ♣J and not the ♣K. The squeeze line without the club play works on the same ♥/♦ distribution but just needs LHO to have the ♣K (with the J anywhere), so I think establishing the hearts dominates that line (unless the bidding or something places the K for you).

[JLOGIC]

I guess third hand didn't play his stiff jack at trick one, or you wouldn't be posting.

 

:rolleyes:

 

Are you sure it's not J8x?

[aguahombre]

Are you sure it's not J8x?

He would get me. Wouldn't be the first time.

[nige1]

deleted

[JLOGIC]

He would get me. Wouldn't be the first time.

 

Heh. A good example of playing the card you're known to hold.

[phil_20686]

I have to admit I thought this was a madatory false card position whenever declarer rises with an honour in dummy. Would play the J from Jx Jxx J8xx J9xx.

 

 

Much harder to know what to do if he plays low in dummy, as from Jxx or Jx you could be setting up a finesse vs the diamond 7 if you have Jx, Jxx and south has A8(x). Of course, that basically cant happen when they rise as declarer either has stiff ace or just always 4 tricks.

[Fluffy]

sigh, I emember the hand, both declarers went for the same wrong line.

 

This might somehow depend on the chances that you get clubs right, if clubs are close to 75% to get right then club line sounds much better.

[rhm]

 

No inference can be drawn from auction or lead (except that RHO has the ♦J lol). I can basically see two lines:

 

1) play a club up and guess right. If it holds, you're in great shape. If not, you're ok with hearts 3-3.

What makes you sure that oponents will not win with the ♣K, whoever got it. You still need a red suit to break or a squeeze thereafter.

 

2) play 4 rounds of hearts. If it goes wrong, then win with diamonds 3-3 or a minor suit squeeze vs LHO.

There are other options. For example a line I find attractive:

Play 3 rounds of ♥s. If ♥ break 4-2, cash ♦s. If they are 3-3, give up a ♥ and claim.

If not, the red suit lengths are likely in different hands and opponents will have to discard at least 2 black cards, more likely ♠s than ♣s.

Cash ♠ before exiting in hearts and hope the defender with length in ♥ will have to return a ♣.

 

Rainer Herrmann

[whereagles]

Rainer: I said it wrong. If the club king holds, you just clear the hearts of course. I meant if the club up works: either the king shows up on the left or you insert the ten and it drives out the king.

 

Just for clarification, LHO is perfectly capable of ducking a low club from hand holding Kxx of clubs. Not that he would at table, but he might just do it.

[AlexJonson]

Nice problem.

 

Given you can develop a second club trick when the first round fails (Hx 'onside') or a third club trick when the first round succeeds (various Hxx positions), I would be surprised if playing on clubs was worse than playing on hearts. I would postulate playing on clubs is better.

[nige1]

Possible compromise: If ♥ are 4-2 then

• If RHO has 4♥ then concede a ♥ and play for a minor-suit squeeze,
• If LHO has 4♥ then adopt Rainer's line: cash ♦ and if RHO has 4+♦, try to endplay LHO .

[gszes]

Hi all, I need some numbers here. Come and help me out :)

 

[hv=pc=n&s=sa75hak642da52ca5&n=skq3hq3dkq74cqt62]133|200|South to play 6NT on the 10 of diamonds lead.[/hv]

 

No inference can be drawn from auction or lead (except that RHO has the ♦J lol). I can basically see two lines:

 

1) play a club up and guess right. If it holds, you're in great shape. If not, you're ok with hearts 3-3.

 

2) play 4 rounds of hearts. If it goes wrong, then win with diamonds 3-3 or a minor suit squeeze vs LHO.

 

What's best? Thx!

 

I find myself scratching my head over those that want to play clubs first----you are (almost certainly)

giving up on making 7 and possibly setting yourself for no reason if h or d dont break 33.

 

If hearts break 33 you are playing for 7 via a squeeze in minors ---LOP

win dia in dummy

heart Q

heart to K

heart A (pitch club)

CLUB A (if K falls claim 13) vienna coupe but only targets lho not both opps

-----if the club A and Q were reversed this squeeze would work against both

spade

spade

spade ending in hand

heart pitching club

heart pitching club Q if no club K has appeared

see if dia break 33

no risk play for overtrick

 

If hearts break 42 and rho wins and leads a club assume lho has the K and use

the lop from above--if LHO wins heart and leads a club (you get a free finesse)

insert the Q (claim if it holds) if it is covered play lho for the club J and 4 dia

or 33 diamonds. If opps make any other switch after winning the heart fall back

on lop from above trying to squeeze lho holding club K and 4 dia or 33 dia.

 

If hearts are 51 or 60 stop playing hearts after 2 rounds (cant afford club pitches).

you now need either (A) 4 dia and 2 clubs or (B) 3 dia and 3 clubs Play a couple of rounds of

spades to see if anyone shows out and gives you a reason to choose either A or B.

 

Trying to score 3 club tricks is way harder than playing for 2 clubs and 33 diamonds so we

will try to find (LHO with KJ or KJX) or (rho with singleton K or KJ). If none of those 4 show up

we settle for 2 clubs and 33 diamonds. After the 2 rounds of spades mentioned above lead the

club A and another club. If lho started with KJ or KJx it should be obvious If rho

drops the club K under the ace I would try a club to the T and claim if it holds. If rho drops

J under the A I would duck the next club hoping RHO started with KJ tight.

When you lead the small club toward the Q and no helpful honor has fallen take your best guess

for a 2nd club and hope dia are 33 GOOD LUCK.

[AlexJonson]

Yes, of course, but the question is how exploitable LHO is on a club play. That's why the difficulty in attaching numbers. Does LHO play the club King when he has it?

[phil_20686]

Yes, of course, but the question is how exploitable LHO is on a club play. That's why the difficulty in attaching numbers. Does LHO play the club King when he has it?

 

Clubs is definitely better, in %, even before taking into account the >50% chance to guess it.

 

If you guess clubs you will make if either red suit is 3-3 or if either the diamond guard or the final club honour is with the long hearts. I.e. basically 50*(1-0.65*0.65*0.5*0.5)= 45%

 

If you guess clubs wrong you will still make

 

(1) When hearts are 3-3 = 0.5*0.355= 18%

(2) When hearts are not 3-3, but diamonds are 3-3, and the hearts are with the club honour 0.5*0.65*0.35*0.5=6%

(3) When hearts are not 3-3, diamonds are not 3-3, but clubs diamonds and hearts are together = 0.5*0.65*0.65*0.5*0.5=5%

 

I.e we are basically up to 75%.

 

If you play hearts at once you will make

 

(1) when hearts are 3-3 - 35%

(2) when hearts are 4-2 and either diamonds are 3-3 or 4 diamonds and the club K with LHO. - 48*(0.35+0.65*0.25)=25%

(3) when hearts are worse, and both the clubs and diamonds work, - 0.15*0.35*0.5=3%

(4) when the hearts are worse, and the clubs work, and the long diamond is with the long clubs with LHO. 0.15*0.65*0.5*0.25=1%

(5) when the hearts are worse, the clubs work, and the long diamond is with the long heart. 0.15*0.65*0.5*0.5= 2%

 

for a total line of 66%.

 

So its better to play clubs even if you dont guess better than 50%. The main reason being because playing hearts first destroys lots of your best squeeze options.

 

Obvio there are composite lines, but I dont have endless time...

 

EDIT to include the possibility of a heart-diamond squeeze, case B5 above. Also, note that I didnt take account of the fact that two long suits in one hand is appreciably less likely than split, just used half for the chance of a given guard being in a given hand.

[whereagles]

Yes, of course, but the question is how exploitable LHO is on a club play. That's why the difficulty in attaching numbers. Does LHO play the club King when he has it?

 

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.

[rhm]

Clubs is definitely better, in %, even before taking into account the >50% chance to guess it.

 

If you guess clubs you will make if either red suit is 3-3 or if either the diamond guard or the final club honour is with the long hearts. I.e. basically 50*(1-0.65*0.65*0.5*0.5)= 45%

 

If you guess clubs wrong you will still make

 

(1) When hearts are 3-3 = 0.5*0.355= 18%

(2) When hearts are not 3-3, but diamonds are 3-3, and the hearts are with the club honour 0.5*0.65*0.35*0.5=6%

(3) When hearts are not 3-3, diamonds are not 3-3, but clubs diamonds and hearts are together = 0.5*0.65*0.65*0.5*0.5=5%

 

I.e we are basically up to 75%.

 

If you play hearts at once you will make

 

(1) when hearts are 3-3 - 35%

(2) when hearts are 4-2 and either diamonds are 3-3 or 4 diamonds and the club K with LHO. - 48*(0.35+0.65*0.25)=25%

(3) when hearts are worse, and both the clubs and diamonds work, - 0.15*0.35*0.5=3%

(4) when the hearts are worse, and the clubs work, and the long diamond is with the long clubs with LHO. 0.15*0.65*0.5*0.25=1%

 

for a total line of 64%.

 

So its better to play clubs even if you dont guess better than 50%. The main reason being because playing hearts first destroys lots of your best squeeze options.

 

Obvio there are composite lines, but I dont have endless time...

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

[phil_20686]

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.

[phil_20686]

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.

[gnasher]

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.

[AlexJonson]

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).

[nige1]

[hv=pc=n&s=sa75hak642da52ca5&n=skq3hq3dkq74cqt62]133|200|

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.

[/hv]