Thursday, September 23, 2010

Finesse played as a suicide compound

♠ A 10 3
A 4 2
Q 7 6 2
♣ A 9 8
♠ Q 9 2♠ J 7 5 4
6 5J 10 9 8
A K J 10 58 3
♣ Q 10 2♣ J 5 3
♠ K 8 6
K Q 7 3
9 4
♣ K 7 6 4

West
North
East
South
1 1NT Pass 2♣
Pass 2 Pass 3NT
All Pass

J led. I ran this to my ace and crossed to dummy with another heart to lead a diamond. The Q was allowed to hold, then I exited a diamond. When West ran diamonds, East had to pitch 2 more black cards in this ending:

♠ A 10 3
♣ A 9 8
♠ Q 9 2♠ ? ? ?
10 9
♣ Q 10 2♣ ? ? ?
♠ K 8
Q 7
♣ K 7

East must unguard a black suit. Win West's continuation with a king in dummy, then cross in the suit East doesn't guard and back to dummy's remaining K. One of these tricks will squeeze East again in the other black suit and hearts, then Q will squeeze West in the black suits.

As shown, West could defeat this by exiting without cashing all diamonds. In practice, though, I held ♠J (you did notice the very light 1NT overcall, right?) and could always fall back on that finesse.

The BBO record is here.

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Wednesday, August 18, 2010

Which squeeze?

Matchpoints

♠ 3
Q J 4 3
A Q J 4
♣ K 9 3 2
♠ A K Q 10 6 4
K 5
K 5 2
♣ A 7

You're declaring 3N against a diamond lead from a defender very fond of passive leads. You win, play a heart to the K and Ace, and a club comes back. How do you play for 12 tricks? Let's assume that the defense isn't very deep; the inferences from not ducking HA or not leading a 2nd heart are too complex.

Discussion below...




You might as well run diamonds and come down to:

♠ 3
Q J 4
♣ K 9 3
♠ A K Q 10 6
5
♣ 7

No chances have been eliminated by doing this. From here, I'm pretty sure nothing is given up by cashing hearts, either (since only one player can guard that suit). After that, there's a fork, though:

[All lines work when the spades split or SJ falls, both have some vig for 5-2 clubs and a club-something squeeze]

a) test spades, then hope for a double squeeze around clubs. Requires long heart on left, long spade on right.

b) cash CA, then hope for spades and hearts in the same hand.

[If someone shows out on hearts, play RHO for spade length (likely if he's short in hearts, necessary if he's long) and choose accordingly]

How do you compare majors divided in a specific way vs majors together but in either hand? See Rubens's latest book. Perhaps I'll come back later and work it out in detail, but I'm pretty sure line b comes out slightly ahead.

For example, assume both red suits are 3-3. Then spades, if they don't split, are very likely to be 4-2. That would make it 5:3 that the odd heart is in the other hand, but that only works when it's hearts-left-spades-right-not-vice-versa, which cuts the odds to 2.5:3. But, it gets a bit closer after accounting for 5-1 spades.


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Tuesday, August 17, 2010

Test Your Play Again -- solution

I posted this recently:

Matchpoints, favorable.

♠ 3 2
Q 9 4 3
K
♣ K Q 10 9 3 2
♠ A Q J 6 4
J
A 9 5 2
♣ A 8 7

This is slightly modified from a hand I played on Saturday. LHO opened 1♠, RHO passes, and you wind up in 3N. ♠10 led, RHO shows out, pitching a diamond. When you play a club to the king, everyone follows.

How do you play?

Seems like LHO must have all the major suit honors. So you could try running all your minor suit winners to come down to a 4 card ending, then exit a heart to lose 2 hearts but score 2 spades at the end, for 11 tricks total.

However, even if LHO has both heart honors, the defense might be able to defeat this plan. How do you counter?

Answer below...



The problem is that LHO can pitch a heart winner in order to hold a diamond link to partner, who will have some good diamonds left. So, after ♣K (in case they're 4-0), unblock
K and play a heart. LHO can't cash 2 hearts or your 11th trick is established, but the position becomes a trick tighter. In the 3 card ending LHO must keep 2 spades and the other heart winner, and now it will be safe to throw him in.

In practice, one of my small diamonds was a heart. I played this way and successfully executed the endplay, but I could have almost as well just established a heart trick.

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Sunday, August 15, 2010

Test Your Play Again

Matchpoints, favorable

♠ 3 2
Q 9 4 3
K
♣ K Q 10 9 3 2
♠ A Q J 6 4
J
A 9 5 2
♣ A 8 7

This is slightly modified from a hand I played on Saturday. LHO opened 1♠, RHO passes, and you wind up in 3N. ♠10 led, RHO shows out, pitching a diamond. When you play a club to the king, everyone follows.

How do you play?



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Tuesday, August 3, 2010

Test Your Play -- solution

♠ A J 7 4 3 2
Q
A 10 2
♣ J 4 2
♠ 10
A K 10 6 4 2
K Q 9 5
♣ 10 7

West
North
East
South
1
Pass 1♠ Pass 2
Pass 3♣ Dbl 3
Pass 4 All Pass

Let's say the defense starts 3 rounds of clubs as you ruff (LHO started with Axx; for purposes of this problem you can assume RHO has 5 clubs) and all follow to the Q. Now what?

As discussed yesterday, I crossed back with a low diamond to play 2 more trumps, RHO pitching a club on the 3rd round. That left this ending:

♠ A J 7 4
A 10
♠ 10
10 6
Q 9 5

It seems like you basically have to pick up diamonds, and that playing for 3-3 or Jx is best, but I figured that I didn't have to do that right away. So, I tried A (both follow, no J), ♠A and ruffing a spade. RHO followed with the king and the eight. Seems awfully likely that he has KQ87, so I exited my last trump, pitching the blocking 10 and endplaying LHO.

The main hint is "the blocking 10". Say I had unblocked that card at trick 5, leaving a very slightly different end position:

♠ A J 7 4
A 2
♠ 10
10 6
Q 9 5

Now you have a much better option: ♠A, spade ruff, A, spade ruff.

Case 1: LHO follows to 3 spades, and must be 3=4=3=3, so cash your diamond and concede trick 13.

Case 2: LHO only has 2 spades. Now she has 2 losing options: overruff and lead a diamond into your tenace, or pitch a diamond, allowing you to complete your elopement.

But, I think you can do better still. See below.



Basically, if RHO shows up with heart length, you'll probably regret unblocking 10. So, I think the best line is to not touch diamonds, but cross back to hand with a spade ruff. Now if LHO shows up with heart length, play along similar lines. If RHO shows up with heart length, then if he had a stiff spade play for 3-3 diamonds. If not, play K and hook 10. If RHO started with 2425 with both red jacks, you'll go down.

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Monday, August 2, 2010

Test Your Play

♠ A J 7 4 3 2
Q
A 10 2
♣ J 4 2
♠ 10
A K 10 6 4 2
K Q 9 5
♣ 10 7

West
North
East
South
1
Pass 1♠ Pass 2
Pass 3♣ Dbl 3
Pass 4 All Pass

Let's say the defense starts 3 rounds of clubs as you ruff (LHO started with Axx; for purposes of this problem you can assume RHO has 5 clubs) and all follow to the Q. Now what?

I think there's a great line, including at least one very pretty variant. A sort of hint is below the fold: the inferior line I actually took.




I crossed back with a low diamond to play 2 more trumps, RHO pitching a club on the 3rd round. That left this ending:

♠ A J 7 4
A 10
♠ 10
10 6
Q 9 5

It seems like you basically have to pick up diamonds, and that playing for 3-3 or Jx is best, but I figured that I didn't have to do that right away. So, I tried A (both follow, no J), ♠A and ruffing a spade. RHO followed with the king and the eight. Seems awfully likely that he has KQ87, so I exited my last trump, pitching the blocking 10 and endplaying LHO.

More on Tuesday.

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Sunday, July 25, 2010

All the compound squeezes

I've spent a lot of time enumerating and trying to name various squeezes. Here's a quick summary of all the compound squeezes (pure, without trumps), just based on naming conventions. I think a name should contain enough information to specify the whole squeeze. Concise names should do little more, but as squeezes get more hairy it can be nice to have some redundancy. Here, I'm trying to be concise. This might be (i.e. probably is) only useful to me.

1. There are type-R (2 double threats opposite a lone basic menace), type-L (1 double threat opposite a basic menace and an adjacent double threat), and Alternate Threat (like type-L, except the adjacent double threat suit also has an alternate threat in the other hand). In both cases, one hand has only one menace, designated the "lone" menace.

2. Type-R and Type-L can be restricted or unrestricted. Unrestricted basically means that the lone menace is recessed -- this makes room for idle cards opposite so you can run the free suit.

3. The standard "basic" menace (i.e. guarded by one opponent who is under the menace) is just a 1 card menace. If an entry is required, it might become "2-card", i.e. Ax/x. Recessing is often required to make room in the other hand, this can make a 1-card a 2-card-non-communicating (2CNC, Ax/-), or a 2-card a "recessed" (AKx/x). If an entry is required to the opposite hand, it can become "blocked" (xx/A), or "twin-entry" (Axx/Kx).

4. The standard double menace in a pure compound is a 2-card (Ax/x). This can be recessed to make room opposite, or twin-entry to add an entry opposite. A 3-card might also be necessary (AKx/xx, where both entries are important -- contrast with "recessed"). In alternate-threat squeezes, either a 2C or a 3C might need an alternate threat: 2-card-alt (Ax/xx) or 3-card-alt (AKx/xxx).

There are 2 double menaces in a compound squeeze. In a type-L, one is "adjacent" to the basic menace and the other is "opposite". In a type-R, both are opposite. Often one of them needs some extra feature, but it doesn't matter which has it (since it's symmetrical).

5. The free suit is normally 2 winners with the lone menace. In an unrestricted squeeze, they both might be opposite; these positions are called "adjoints". Sometimes, a late entry is used in the free suit -- these have "balanced" free suits, such as AK/xx (Ax/Kx also fine). Sometimes the penultimate free winner needs to be in the opposite hand, a "blocked free suit" (though again Ax/Kx would work fine).

In my naming convention, the type (R/L/alternate) describes the basic layout of the menaces and minimum necessary (but not sufficient) entries (see row I, II, and II-C). "Unrestricted" says something about the lone menace: that it has an extra winner without (necessarily) a corresponding link opposite. But, each basic family potentially has some additional entry requirements that are satisfied by upgrading one or more standard menaces. The type of upgrade and the upgraded menace(s) constitutes the rest of the name.   Often specifying which menace is upgraded is redundant, but still helpful.

In hand diagrams, spades is always basic and in North (guarded only in West), clubs is always free, and the red suits are always double menaces, guarded by both opponents (diamonds is always opposite, in South; hearts might be in either hand). An 'o' designates an idle card.

In the outline, every line using arabic numerals corresponds to a distinct compound, where as long as East can't stop spades, declarer can take the rest (might also require that the hand with CA is on lead).

I. Type-R (implies at least x/x/x/AK opposite -/Ax/Ax/o)

    A.  Unrestricted (implies spades is 2CNC or recessed: Ax/- or AKx/x)
  • requires a reentry to the basic hand, could be in basic suit (B) or one of the double menaces opposite (O). Free suit (F) not possible since it's cashed first.
          1.  Type-R Unrestricted Recessed basic
               AKx/x/x/AK opp x/Ax/Ax/oo

          2.  Type-R Unrestricted Twin-entry opposite
               Ax/Kx/x/AK opp -/Axx/Ax/oo
  • both of the above could be "adjoint", with the free winners in the other hand.
  • If the free suit is blocked, play is harder but nothing extra needed.
   B. Restricted
  • requires a reentry to the basic hand, could be in B, O, or F:
          3.  Type-R Restricted Two-card basic
               Ax/x/x/AK opp x/Ax/Ax/o

          4.  Type-R Restricted Twin-entry opposite
               x/Kx/x/AK opp -/Axx/Ax/o

          5.  Type-R Restricted Balance free suit (implies 2CNC basic)
               Ax/x/x/AK opp -/Ax/Ax/xx

II. Type-L (implies at least x/Ax/x/o opposite -/x/Ax/AK)

   A. Unrestricted (implies diamonds is recessed, AKx/x)

          6. Type-L Unrestricted (already fully specified)
              x/Ax/x/oo opp -/x/AKx/AK
  • has an adjoint with free winners in the other hand.
  • If the free suit is blocked, requires a reentry to the long free suit winner (3 possibilities if you include xx/AKQx as a possible double menace.)
   B. Restricted (implies diamonds is *not* recessed)
  • Requires a Spade/Heart reentry to the free suit after cashing HA, plus a late Spade/Diamond entry to give force to the basic menace (and now entry-less heart menace). All 4 combos ([S|H]-[S|D]) work:
          RFL squeezes:
          7. Type-L Restricted Twin-entry basic (both entries in spades)
              Axx/Ax/x/o opp Kx/x/Ax/AK

          8. Type-L Restricted Two-card basic, Twin entry adjacent
              Ax/Axx/x/o opp x/Kx/Ax/AK

          B1-Twin-entry squeezes:
          9.  Type-L Restricted Blocked basic, Twin entry opposite
               xx/Ax/Kx/o opp A/x/Axx/AK

         10. Type-L Restricted Twin entries adjacent and opposite
               x/Axx/Kx/o opp -/Kx/Axx/AK

   C. Alternate threat (implies at least Ax/Ax/x/o opp -/xx/Ax/AK)
  • SA is in the way when West unguards diamonds, need an entry to clear it while still retaining a heart winner (the SA itself is required to make room for the alternate threat). This entry can be in any suit (but if in the free suit, requires a reentry to South):
          11. Type-L Alternate Recessed basic
                AKx/Ax/x/o opp x/xx/Ax/AK

          12. Type-L Alternate 3-card-alt adjacent
                Ax/AKx/x/o opp -/xxx/Ax/AK

          13. Type-L Alternate Twin-entry opposite
                Ax/Ax/Kx/o opp -/xx/Axx/AK

          14. Type-L Alternate 3-card opp w/blocked free suit
                Ax/Ax/xx/A opp -/xx/AKx/KQ
  • In 14, the free suit blockage is essential.  In 11-13, there are some blocked free suit variants not shown.

To recap:

[Note that in restricted squeezes, the common pattern is to cash one free winner, potentially need to do some stuff ending in the other hand, and then need a reentry to the free suit. I strive to only use "reentry" to refer to getting back to the free suit.]

Type-R unrestricted needs a reentry: basic (1) or opposite (2). Adjoints possible.
Type-R restricted needs a reentry: basic (3), opposite (4), or free (5).
Type-L unrestricted needs nothing more (6). Adjoint possible.
Type-L restricted can be an RFL needing a spade (L) entry plus a reentry in spades (7) or hearts (8); or it can have a twin-entry opposite + reentry in spades (9) or hearts (10).
Type-L alternate-threat (implicitly restricted) can have an entry to the basic hand in any suit: 11-14.

I believe that's all of the pure compounds: 14 distinct positions, plus 3 adjoints (plus maybe 2 or 3 variants on a type-L unrestricted w/blocked free suit, and some alternate threat blocked free suit variants).  In most cases, the free suit being blocked is not a big deal, I don't treat those as separate positions.

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