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tricky 4s

#1 User is offline   Stephen Tu 

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Posted 2017-September-06, 02:31

IMPS.
What's the best line?


west leads the 5.
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#2 User is offline   The_Badger 

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Posted 2017-September-06, 05:09

Just having a quick look, at IMPs (teams) I would take the first trick in dummy, finesse in s playing J first, then finessing the Q, and have a and entry for the double finesse in s looking to take three tricks in s, s, and s plus A. It's too much of a greek gift at trick one to work on getting four tricks thanks to a favourable lead: I'd rather be in dummy with a tempo. That lead looks suspiciously like a singleton.
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#3 User is offline   dokoko 

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Posted 2017-September-06, 23:28

I insert the 10.

[1] If it holds the trick, I finesse Q and continue with the ace eventually. If spades are 4-1 I play a spade to the 9 take the club return draw the last trump and hope for the K onside. If the spade finesse loses, I will win the return in hand and cash A. If spades are 4-1, I am in the same situation as in [2].

[2] If it is covered (as expected) I win in hand and continue with A and Q. If spades break 3-2 I am home. Even if East wins and gives partner a heart ruff, I can discard a club on the hearts, eliminate the hand and then run a diamond from dummy. If spades are 4-1 and a club comes back, I win in hand, play a spade to the 9 and finesse Q. If this wins, I am home; if this loses and opps can manage a heart ruff I am down. Otherwise I have to rely on the J being onside. If spades are 4-1 and opps duck Q (best) see [1].

So I think I win when spades are 3-2 or K is onside (ignoring a 5-0 trump break). It might be better not to finesse Q in [1] in case West has the stiff K or East wins the second round of trumps with Kxxx.
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#4 User is offline   GrahamJson 

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Posted 2017-September-11, 11:31

View Postdokoko, on 2017-September-06, 23:28, said:

I insert the 10.

[1] If it holds the trick, I finesse Q and continue with the ace eventually. If spades are 4-1 I play a spade to the 9 take the club return draw the last trump and hope for the K onside. If the spade finesse loses, I will win the return in hand and cash A. If spades are 4-1, I am in the same situation as in [2].

[2] If it is covered (as expected) I win in hand and continue with A and Q. If spades break 3-2 I am home. Even if East wins and gives partner a heart ruff, I can discard a club on the hearts, eliminate the hand and then run a diamond from dummy. If spades are 4-1 and a club comes back, I win in hand, play a spade to the 9 and finesse Q. If this wins, I am home; if this loses and opps can manage a heart ruff I am down. Otherwise I have to rely on the J being onside. If spades are 4-1 and opps duck Q (best) see [1].

So I think I win when spades are 3-2 or K is onside (ignoring a 5-0 trump break). It might be better not to finesse Q in [1] in case West has the stiff K or East wins the second round of trumps with Kxxx.

I don't think that you can eliminate the hand and then end up in dummy to lead a diamond. You can lead a diamond from hand, making the contract if W has the jack or east has the king. Or you can lead the queen from hand, making if west has the king or east has the jack.
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#5 User is offline   dokoko 

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Posted 2017-September-13, 11:35

View PostGrahamJson, on 2017-September-11, 11:31, said:

I don't think that you can eliminate the hand and then end up in dummy to lead a diamond. You can lead a diamond from hand, making the contract if W has the jack or east has the king. Or you can lead the queen from hand, making if west has the king or east has the jack.


I don't try to eliminate as it probably won't work when spades don't break and there should be no problem if spades behave.
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#6 User is offline   gszes 

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Posted 2017-September-14, 11:23

trick 1 heart T holds (I see little downside to trying for a 100% chance of getting 4 hearts and providing me with another dummy entry)
trick 2 try running the spade 9 and if it holds follow with the J also intending to run it. We make anytime rho started with K Kx Kxx Kxxx (4 spades 4 hearts and 2 aces and can take the dia finesse for the overtrick since we never lost a trick)

too many variations if the spade 9 loses and the defense that follows but worst case scenario seems to be we depend on the dia finesse for 10th trick.

If heart T is COVERED (what you thought this would be easy?)
trick 2 it seems the spade A followed by the spade Q is best since we can always draw and force a dummy entry while drawing the remaining trumps though this will mean relying on the dia finesse for 10th trick if trumps split 41.

Similar approach to dokoko but the play in the trump suit provides us with a little bit better chance of making when the spade K is onside and who doesn't like a free shot at an overtrick that has a 50% chance of gaining an imp (and is even better off when it LOSES :))?
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#7 User is offline   fourdad 

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Posted 2017-September-16, 03:58

View PostStephen Tu, on 2017-September-06, 02:31, said:

IMPS.
What's the best line?


west leads the 5.


Play 10!h and win in hand when covered.
Potential losers are 1!s, 1!c, 2!d.

play A!s and low to J. Looking to eliminate club on good heart. Even if trumps do not behave, opps get their extra trump while club is thrown on heart.
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#8 User is offline   dokoko 

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Posted 2017-September-16, 09:12

View Postfourdad, on 2017-September-16, 03:58, said:

Play 10!h and win in hand when covered.
Potential losers are 1!s, 1!c, 2!d.

play A!s and low to J. Looking to eliminate club on good heart. Even if trumps do not behave, opps get their extra trump while club is thrown on heart.


So if I understand right you play

1. 5TJA
2. A235
3. 8xJK
4. xAx5
5. 9247
6. 63Q6
7. KJx4
8. 7 over to you
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#9 User is offline   Stephen Tu 

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Posted 2017-September-21, 18:39

So I think the two basic lines are very close and it wasn't clear in my mind which was ahead until I made a fairly exhaustive calculation, my teammates were quite unsure.

The two plausible lines are:
1. Try the ten, if covered, SA, then something like s8 to s9 or ST to SJ (if someone has Kxxx and decides to duck, you want to be in dummy to take the diamond hook)
If spades are 4-1, presumably a club comes back, cross in trumps and take the diamond hook. If it wins draw trumps and claim. If it loses and the opps maneuver diamond or heart ruff you are down. If not you have a second chance diamond hook.
2. High heart from dummy, to be assured you can take the spade finesse, try running the s9, repeat if wins.

I made the assumption that LHO would not falsecard on lead, and the methods at the 2 tables happened to be 3rd/low at one table, and Polish style 2/4 at the other, so the idea is that unlike with 4th best leads combined with non-MUD, you don't have to end up guessing if LHO had 3 small or 4 to the J as different cards are led. The magnitude of the calculations differed depending on which style was on lead. I also ignored overtrick/undertrick calculations

If spades are 3-2, the only time you can really go down is if both DKJ are offside. Line 1 gains if the SK is offside, and the lead was singleton or doubleton, so you get your 4 heart tricks. Line 2 gains if RHO has Kx doubleton of spades and gives LHO the heart ruff. But if spades are 3-2 LHO/RHO, it's 3:2 that the SK is offside. So this favors line 1.

If spades are 4-1, line 1 tends to gain if the SK is stiff by guaranteeing the 4 heart tricks (when rest of hand is unfriendly), and when LHO has 4 to the K (extra heart trick some times, extra entry to dummy to take a second diamond hook if can avoid heart ruff)

The big gain for line 2 is when spades are 4-1 with RHO having Kxxx, here you both pick up the spades and often still have 4 heart tricks. Line 1, you will need DK onside, or at least one of DK/DJ onside and avoid heart or diamond ruff.

finessing also gives some extra chances of making if 5-0 onside (e.g. 3+ hearts and DK onside)

Both lines have high success rate, but my calculations, if I didn't screw up, showed 1-2.5% making advantage for the HT line, depending on the lead agreement (lower advantage vs. 2/4).
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