Author Topic: I don't like the DARE solution  (Read 2115 times)

wackojack

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I don't like the DARE solution
« on: December 21, 2021, 06:40:36 PM »
This hand came up in the recent DARE tourney 
                       !S Q4
                       !H AK543
                       !D KJ62
                       !C A7

  !S K1076                          !S 53
  !H J9                                !H Q1086
  !D 108                              !D Q975
  !C J8653                           !C Q109
                         !S AJ982
                         !H 72
                         !D A43
                         !C K42
Bidding 1 !H - 1 !S - 2 !D - 3NT - pass
Lead 5 !C

It looks like this lead is likely from 4+ length so initial duck is a good idea.  I play 7, RHO the Q and me the 2.  Then  !C Q, 4 , 3 Ace.
So LHO was leading from 5 cards to Jack and so can only afford to let RHO in once.

My simple mind thinks that we can do no better than finesse twice into LHO.  This will give us 4 tricks in  !S 75% of the time giveing us 4 !S +2 !H + 2 !D + 2 !C =10 and perhaps more if  !D s behave. 
(Just noted that the post-priori odds are better than this because when LHO has 5 clubs, he is less likely than RHO to have 4 spades)  This would increase the chance of the double finesse succeding making to well over 80%)

This was not the DARE solution.

It was I think: take the initial lead with the K !C in hand and lead a low spade.  If LHO takes with the King you are home but that is only a 50% chance.  So if RHO takes with   
 King and leads another club, this is what you do:
Take with your A !C and test the spades.  If 3-3 you are home.  If LHO happens to have started with 4 you play  !H AK noting that all follow.  If you find that LHO was 4225, then RHo's distribution is 2443 and can be endplayed into leading away from  !D Q.

I am not convinced that this is a better chance.  Could Ken do the Maths?

 





 

kenberg

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Re: I don't like the DARE solution
« Reply #1 on: December 23, 2021, 02:19:04 AM »
I took the first club in hand, I led a spade, Lho ducked, I still went down.  now had 2 spade tricks, the Q I just tool and the A to be taken later, but I need 3 tricks in some suit, Where? It's tricky. Ar least I did not succeed.

With the Dare hands I like to look back on them later. Sometimes I can see that while I made the hand my play was not optimal. And when I go down, of course I want to see if I can find the best line. My line was not (completely) crazy. After the spade duck, I led a small heart from the board. I The plan is to settle now for 2 spade tricks and 2 club tricks and try for five red tricks. Maybe the hearts split, maybe the diamond finesse is on. Well, didn't happen.
You cannot effectively test spades after the spade duck. If, at T3, you lead a small spade to the 9 then Lho takes the t and leads a second club, establishing clubs while the J is an entry (Rho has to dump that club Q at T1 or on the second round of clubs). Or, if you play a spade to the A at T3 and another spade at T4, Lho wins, does not cast his other spade since that sets up your 9th trick. He leads a club, establishing clubs.

I can see, double dummy,  various ways to make the hand, including how to follow through if the first two tricks are club K and small spade toward the board. Q winning I have not yet decided, single dummy, the best line. I think a club duck at T1 is right.

I try hard, when playing Dare, not to say Oh, this is a lesson hand, surely the finesse fails. I try to see the best line just as a hand.

As to math, that's more than a bit tricky.
« Last Edit: December 24, 2021, 12:44:57 AM by kenberg »
Ken

kenberg

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Re: I don't like the DARE solution
« Reply #2 on: December 23, 2021, 02:12:28 PM »
More detail;
If hearts are 3-3 we are probably making this but if they are 4-2 we are limited to 3 heart tricks. We will get only 2 club tricks So to make this we will need either 2 spade tricks and 2 diamond tricks or 1 spade trick and 3 diamond tricks. Or possibly we can get 3 !S tricks,  Let's use ( !S,!H,!D,!C) to indicate the number of tricks. So we hope, if !H don't split, to get either (2,3,2,2) or *2,2,3,2) or maybe (3,2,2,2) tricks.

One reason the math is tough is that there are many variants and, except for the opening lead, we do not control what the opponents do.

Suppose we duck at T1 and !C are continued. putting us on the boar d with the A.
T3: Lead the !S Q, Let us assume that Lho takes his K although he might not.
T4: another !C, won in hand.
T5,6: Cash the A,J of !S.
uh oh. Lho still has a !S winner so if we lay another !S to establish our 5th !S, they get (2,0,3,0)=5 tricks. But: Lho has a lot of black cards so Rho has a lot of red cards. We can make this.
T 7,8,9: A,K and another !H, throwing a !S from hand. Rho is in, he can cash another !H, but then must lead a !D. We get 5 redtricks.

Is this double dummy? Well, sort of. We chose to throw Rho ib with a !H rather than just take the !D finesse. But we do know Rho has a lot of red cards. Presumably at T2 Lho folloed with the !C 3 to let his pard know he started with 5. But then again, he might see tis as best kept secret. If we beleive Lho started with 9 black cards then the throw-in seems right.

Playing os !S at T3 seems right. The suit might be 3-3. and, if 4-2, the T might fall on the second round. And, if neither of these good things happen, then we at least have 2 !S tricks so we need only come up with 5 red tricks.


Will Lho take the K at T3? Maybe not. As I played it, winning the !C at T1 in hand and leading a small !S, it was easier to duck since the K captures only the 4. . When we lead the !S Q at T3 from the board, he gets to capture a Q with his K. If he ducks we can make it, but maybe not obviously T4: small !S to the 9, the T wins, he can lead a 3rd !C, we are ni our hand and cash the !S A, ok, so much for !S but e can do the throw-in as before.

Is this the best line? Beats me. I think I like it better than the one I chose. For one thing, it works.

As I see it, we are searching for the best line of play, not the line that works as the cards lie. Dare uses pre-dealt hands. I like to shift the opponents' cards around some to see when the recommended line works and when it doesn't. Usualy I can eventually see the best line but here I am not yet sure.
Ken

kenberg

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Re: I don't like the DARE solution
« Reply #3 on: December 23, 2021, 02:58:54 PM »
Oh. I did say there was a way to make it after I take the club in hand at T1 and lead a small !S, Lho ducking. The way I am thinking of is very double dummy, so perhaps there is something better.

We have:

T1: win the K
T2: lead a small !S, Q winning.
T3: !C A!
T4 !S to A
T5 !C 4 !
 

                       !S
                       !H AK543
                       !D KJ62
                       !C

  !S K10                              !S
  !H J9                                !H Q1086
  !D 108                              !D Q975
  !C J86                              !C 10
                         !S J98
                         !H 72
                         !D A43
                         !C

!C 4 is led, Lho chooses: He can let hs pard win with the T but that leads to an eventual throwi-n so presumably Lho hops up with the J.  He can cash 2 more !C and we have:


                       !S
                       !H AK5
                       !D KJ6
                       !C

  !S K10                              !S
  !H J9                                !H Q108
  !D 108                              !D Q97
  !C                                    !C
                         !S J9
                         !H 7
                         !D A43
                         !C

If he now cashes the !S K my J is good and I claim.  If he leads a !H I play AK and another forcing Rho to lead !D. If Lho plays a !D after cashing !C, I win with the A in hand and play A,K and another !H.

It works, but very DD.

If there is a simple route after winning the K at T1 and leading a small !S at T2, I am not seeing it.

« Last Edit: December 23, 2021, 03:01:33 PM by kenberg »
Ken

kenberg

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Re: I don't like the DARE solution
« Reply #4 on: December 23, 2021, 09:20:05 PM »
I gave it to the robots:
 


https://www.bridgebase.com/tools/handviewer.html?lin=st||pn|~~M4554ukz,~~M6236iuo,kenberg,~~M172633n|md|2SAJ982H72DA43CK42,SKT76HJ9DT8CJ8653,SQ4HAK543DKJ62CA7,S53HQT86DQ975CQT9|sv|b|rh||ah|Board%204|mb|P|mb|1H|an|Major%20suit%20opening%20--%205+%20!H;%2011-21%20HCP;%2012-22%20total%20points|mb|P|mb|1S|an|One%20over%20one%20--%204+%20!S;%206+%20total%20points%20|mb|P|mb|2D|an|Opener%20two%20rebid%20--%203-%20!C;%204+%20!D;%205+%20!H;%203-%20!S;%2011-16%20HCP;%2012-18%20total%20points|mb|P|mb|2N|an|Balanced%20invite%20--%204-5%20!S;%2010-12%20HCP%20|mb|P|mb|3N|an|3-%20!C;%204+%20!D;%205+%20!H;%203-%20!S;%2014-16%20HCP;%2018-%20total%20points|mb|P|mb|P|mb|P|pc|C5|pc|CA|pc|CT|pc|C4|pc|S4|pc|S5|pc|SJ|pc|SK|pc|C8|pc|C7|pc|CQ|pc|C2|pc|S3|pc|S2|pc|S6|pc|SQ|pc|HA|pc|H8|pc|H2|pc|H9|pc|D2|pc|D7|pc|DA|pc|D8|pc|CK|pc|C3|pc|H3|pc|C9|pc|SA|pc|S7|pc|H4|pc|H6|pc|D3|pc|DT|pc|DJ|pc|DQ|pc|HQ|pc|H7|pc|HJ|pc|HK|pc|DK|pc|D5|pc|D4|pc|ST|pc|D6|pc|D9|pc|S8|pc|CJ|pc|HT|pc|S9|pc|C6|pc|H5|


It seems to me that arter the first four tricks a robot might figure a heart from the board is right, and not just because it is.
« Last Edit: December 24, 2021, 12:22:04 AM by kenberg »
Ken

kenberg

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Re: I don't like the DARE solution
« Reply #5 on: December 24, 2021, 08:37:20 PM »
                          !S Q4
                          !H AK543
                          !D KJ62
                          !C A7




                         !S AJ982
                         !H 72
                         !D A43
                         !C K42

Bidding, uncontested, starting with N: 1 !H - 1 !S - 2 !D - 3NT - pass
Lead 5 !C

The bot took the opening lead on the board. I think I agree with that.
The bot then led a small spade to the J. I think it would be better to start with the spade q from the board. If the Q is covered by the J you can take it, cash the spade J, and lead the spade 9 making at least 9 tricks.
When the spade Q oses to the Q you still have options. Say that they take the Q with the K and play another club. You duck. If they then play another club you take it (of course) and cash the AJ of spades. If spades are 3-3 great. If the T falls on a 4-2 split grat. But it is also fine if Rho shows up with four spades. Just play another spade. If clubs are 4-4 they take two clubs and two spades. If clubs are 5-3 then it is very reasonable to think that it is Lho, not Rho, who started with the five clubs, so Rho is out of clubs.

As it happens, it is Lho who started with the five clubs and four spades. But you still have options, either the diamond finesse (it fails) or the throw-in (it works)
« Last Edit: December 24, 2021, 08:40:33 PM by kenberg »
Ken

jcreech

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Re: I don't like the DARE solution
« Reply #6 on: December 25, 2021, 03:37:50 AM »
I have to admit that I am frustrated by this problem.  I have too many things I want to do, am not in the right place to do them, and if I take action to get to where I want to be, I risk providing the defense a viable alternative to set the contract.

I want to duck the first club, but that necessitates winning the second club in the wrong hand, because I also want to start the spades by leading toward the queen.  To achieve the second desire, I have to burn an entry to my hand, a diamond, which now risks a diamond through if West gets on lead.

So much depends on suits breaking, or specific cards being in the right place, or last resort endplays.  The whole hand stinks with an unnatural risk of not ducking that first club in order to lead the spade toward the queen, hoping for a rise to solve all the problems.  I don't like dragging the spade queen through  or a spade to the jack as my first action in that suit, because if it is wrong, I am still facing a probable repeat finesse in the suit to the danger hand.  I don't really want to start the hearts because when I lose a trick in that suit, East is still likely to have one to continue while West still has a probable entry.

That is why I want to start the spades toward the queen, and if it is allowed to hold, then a spade back to the 9, hoping for the 10 to be onside.  When that doesn't work, I still have a potential 3-3 break or another suit the East cannot return.  But in the meantime, I've lost an entry to try to control which hand I lose the heart to.  It happens that West only has two, but I don't know that until the third round, and now that suit can be used to endplay East.

Simply put, unless the defense is very friendly, this is a hand that you struggle with and the director ends the round while you are still working through the issues.  Not fun at all.

Thank you for bringing this to our attention Jack; it has only disturbed my sleep for two nights.
A stairway to nowhere is better than no stairway at all.  -Kehlog Albran

wackojack

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Re: I don't like the DARE solution
« Reply #7 on: December 25, 2021, 11:25:50 PM »
  My partner ducked the initial club which I think is OK and then after taking the 2nd club led a small spade fom dummy losing the jack to LHO's King.  LHO then made it easy by switching to a diamond instead of pursuing clubs and declarer was then able to establis spades for 9 tricks.  If, however, LHO continues clubs it is still makeable.  Declarer finds that LHO has 4 spades and cannot establish them.  Nevertheless LHO's distribution is now know to be 4225.  So RHO can be endplayed.  This is the position:

            !S -
            !H AK5
            !D KJ6
            !C -
 !S 10              !S -
 !H J9             !H QJ8
 !D 10             !D Q109
  !C J8             !C -
            !S 98
            !H 72
            !D 43
            !C -

Declarer plays AK and another heart and RHO has to lead a diamond into dumm's KJ6. Ken spotted this line but doubted if it was the best.

The stated theme for the hands this week was "counting the hand"  So in this case when LHO's distribution was found out to be 4225 the endplay of RHO became known.  In that respect it conformed with the theme.  However, it is completely unclear to me that the build-up to this endplay was the best line.  I am sticking to the double finesse in spades which a priori gives 75% chance of making 4 tricks in spades.  Adding 2 !C + 2 !D +2 !H gives 10 tricks and chances of 11.  Also since LHO is know to have 5 clubs, he is likely to have fewer spades than RHO and thus the 75% chance goes up to 80+%. As the cards lie however, this line fails because LHO has both the missing honours.

I cannot imagine a top player playing any other line.  My lack of imagination?     

kenberg

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Re: I don't like the DARE solution
« Reply #8 on: December 26, 2021, 03:02:03 AM »
It was the best line I could come up with. I have come to think the first tricks should be won on board, and i would then lead the spade Q, not the small spade, let's look at your suggested line, assuming Lho continues clubs when in with the spade K

 After four tricks the hands are

                       !S Q
                       !H AK54
                       !D KJ62
                       !C

  !S 1076                            !S 5
  !H J9                                !H Q1086
  !D 108                              !D Q975
  !C J3                                 !C
                         !S A982
                         !H 72
                         !D A43
                         !C

Note that Lho kept the J3 in his hand.
Assuming that the C5 at T1 was understood as 4th best, everything so far is consistent with clubs being dealt as 4-4 with Lho holding the J and Rho holding the 3.

Declarer wants to test spades but to do this he must go to the bpard with a spade and then come back with a diamond.

                      !S
                       !H AK54
                       !D KJ6
                       !C

  !S 107                              !S
  !H J9                                !H Q1086
  !D 10                               !D Q97
  !C J3                                 !C
                         !S A98
                         !H 72
                         !D 43
                         !C

Declarer now leads the spade A, lho follows, dummy pitches a red card, Rho pitches a red card.

We do not really know exactly who holds what. In particular, Rho might hold a small club. He doesn't, but he might. If he has a club this could get tricky.


So I think it is not certain.

Now about T1. I say take it on the board and lead the spade Q. If the K appears on your right the contract is safe. You take the A, go to the board in hearts, and lead the small spade intending to play the 9 unless Rho plays the T. You get at least 3 spade tricks, maybe 4, maybe 5. Of course here the Q loses to the K. Unless they now play two more rounds of clubs right away, you have time and entries to play the AJ9 if spades, establishing the 8. So all is well unless the Q loses to the K and they play two more rounds of spades. Ok, that will happen when we work on spades. But there are many ways this could work out, and here, where it doesn't, we have found out about the spades without touching the reds, and Rho had to choose a discard on the third round of spades before he has seen much of your hand.
 

I think this is the best line, but I could be wrong. Also, it is interesting to contemplate what happens if the first spade is ducked by Lho.
 
« Last Edit: December 26, 2021, 01:28:54 PM by kenberg »
Ken

jcreech

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Re: I don't like the DARE solution
« Reply #9 on: December 26, 2021, 03:15:04 PM »
The following url is my vision of the play, ducking the first club, and using a diamond to get to hand to start the spades as I would like. 
https://tinyurl.com/yytmhkje

The problem is, if LHO, when in with the !S 10, does not continue clubs, but switches to diamonds, I think I would now be down - probably losing a spade, two hearts, a diamond and a club.  Holding the !S K and declarer testing the spades, I think LHO has reason to continue working on the clubs, but that is far from a certainty.
A stairway to nowhere is better than no stairway at all.  -Kehlog Albran

kenberg

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Re: I don't like the DARE solution
« Reply #10 on: December 26, 2021, 06:41:46 PM »
Yes, on that line declarer holds a good club and a good spade and has no way to reach either without help from opponents. Will they realize this? They might.

Just for amusement, here is another possible line. I doubt that I would recommend it. Imagine the following beginning:
club 5 taken by A
spade Q runs to K
club 6 to Q and A
small club from hand, throwing a heart. Perhaps Lho lets it ride to his pard's J in which case Rho has to choose a return but suppose Lho hops up with the J.
 
We have:


                       !S 4
                       !H AK54
                       !D KJ62
                       !C

  !S 1076                            !S 5
  !H J9                                !H Q1086
  !D 108                              !D Q975
  !C 83                                !C
                         !S AJ98
                         !H 72
                         !D A43
                         !C

Suppose now Lho cashes both clubs. Throw a heart and a diamond from the table and a heart and a spade from your hand. Now Lho leads a heart. Take it, lead a diamond to your ace, cash the spade AJ throwing a heart and a diamond.

                       !S
                       !H K5
                       !D KJ
                       !C



                         !S 9
                         !H
                         !D A43
                         !C

Rho was squeezed in hearts and diamonds on the last club. Play a diamond to the K and cash the heart king, throwing the spade from hand. Either dummy's last heart is good, or diamonds run.

As noted, this is for amusement. but it might not be crazy. If spades were 3-3 or if the T fell, the 9 would be good. When that doesn't happen, you squeeze.

« Last Edit: January 15, 2022, 04:20:54 PM by kenberg »
Ken