[pclayton]

Sometimes you can discover some amazing things with GIB.

Before you try this hand DD, play it as I had to:

Scoring: IMP

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You reach a decent 6♥ after pard shows you a mini-splinter in spades.

LHO leads the ♣J.

Plan the play.

[xcurt]

Possible lines

(a) win and lead a diamond immediately
(b) HK, HA, HJ if necessary otherwise spade ruff, then test clubs, then diamond finesse if necessary
© try to cash the other high clubs throwing diamonds then lose a diamond then crossruff

I'll be a farmer and take line (b). Assuming everyone follows the HK, I'm making when I catch any two of 4-3 clubs, 2-2 hearts, or the DA onside plus maybe some other rare cases.

[ceeb]

♣A, K, Q & crossruff. Assuming I can read nothing from the club plays, continue ♣ hoping to score a ruff. Whether RHO follows (we pitch the last ♦ of course) or discards ♠ I need RHO to have 7 black cards in order to score my ruffs in dummy, and need LHO to have 7 minor cards to score ruffs in hand. Pretty much.

Edit -- need LHO to have 6 minor cards as only need to score 2 small ruffs in hand, not 3.

[xcurt]

ceeb, on Jul 3 2008, 10:04 PM, said:

♣A, K, Q & crossruff.

This line and the variant where we duck a diamond instead of the last club are just down on 5-2 clubs offside. 5-2 clubs onside we overruff, ruff the spade shift, diamond taken by the ace, win the trump in hand, DK, trump to the table, diamond ruff. We RHO to have started with 5332 or 6232 shape exactly including the DA (or 6322 or 7222 with the DAQ tight).

[gnasher]

xcurt, on Jul 4 2008, 04:23 AM, said:

ceeb, on Jul 3 2008, 10:04 PM, said:

♣A, K, Q & crossruff.

5-2 clubs onside we overruff, ruff the spade shift, diamond taken by the ace, win the trump in hand, DK, trump to the table, diamond ruff. We RHO to have started with 5332 or 6232 shape exactly including the DA (or 6322 or 7222 with the DAQ tight).

I think that after East wins ♦A and returns a trump, it's better to win in dummy, then play ♦K, ♠A, spade ruff, club ruff, spade ruff with dummy's jack. That makes whenever RHO has 3+ spades and 2-4 diamonds

[gnasher]

xcurt, on Jul 4 2008, 03:41 AM, said:

HK, HA, HJ if necessary otherwise spade ruff, then test clubs, then diamond finesse if necessary

A slight improvement is to cash only two trumps ending in dummy, then if RHO has three hearts play the top clubs, throwing a diamond and a spade. If RHO has five clubs as well, cross-ruff clubs and spades (retaining the ace), then lead a diamond towards the king. That makes when RHO has 3 hearts, 5 clubs and 2+ spades.

If clubs turn out to be 4-3, you can draw the third trump and revert to your earlier plan. If they're 5=2, you're in the same position as before.

[ceeb]

xcurt, on Jul 3 2008, 10:23 PM, said:

ceeb, on Jul 3 2008, 10:04 PM, said:

♣A, K, Q & crossruff.

This line and the variant where we duck a diamond instead of the last club are just down on 5-2 clubs offside. [and some compensation when 5-2 onside per gnasher, which may compensate for cases when the crossruff gets overruffed].

True, it's roughly equivalent to 4-3 clubs, which is 62%. As against that, pulling trumps fails a good (I think the ♦A is a favorite to be offside, but never mind that) 1/4 of the time when clubs do break, and succeeds only1/4 of the time that they don't.

Hence as a farmer estimate, since the club break is >50%, better to settle for that than to swap part of that big slice for a similar share of a smaller slice.

[pclayton]

I played the same as Curt and felt the same about my analysis. Two trumps, clubs, then a diamond up. Regretfully, the ♦A was offside and clubs were 5-2. The hand can still be made DD!

Take a look:

Scoring: IMP

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Do you see how?

[xcurt]

I won't post the solution since I finally gave up and checked it with GIB. I have to thank you. I learned something from this hand.

[inquiry]

You would need some very important clues to find this play. I suspect maybe, if you ruff a few spades early on and discover that rho shows up with all those spades (you have to read the cards well to reach this conclusion, but the fall of the spots might help) and sat quietly, you might place the diamond ace on the other side in time to find the right discard on the last top club. I mean with QJTxxx and the diamond A he would have bid over 1♣ (north was the dealer).

Diagnosing this defective squeeze with out the count looks a little tricky, but i think it is just a varient of the vise squeeze that Terrence Reese wrote about. In his book, EW hands would be reversed, and WEST would hold S-Q, DQJ... dummy would hold diamond KTx and a declarer Sx, Hx, Dx... The moving around of the spots and the absences of the pair (QJ) of diamond honors does not change the mechanism, however. At least it looks like a "standard" if a bit warp vise squeeze.

[xcurt]

inquiry, on Jul 4 2008, 10:26 PM, said:

You would need some very important clues to find this play. I suspect maybe, if you ruff a few spades early on and discover that rho shows up with all those spades (you have to read the cards well to reach this conclusion, but the fall of the spots might help) and sat quietly, you might place the diamond ace on the other side in time to find the right discard on the last top club. I mean with QJTxxx and the diamond A he would have bid over 1♣ (north was the dealer).

Diagnosing this defective squeeze with out the count looks a little tricky, but i think it is just a varient of the vise squeeze that Terrence Reese wrote about. In his book, EW hands would be reversed, and WEST would hold S-Q, DQJ... dummy would hold diamond KTx and a declarer Sx, Hx, Dx... The moving around of the spots and the absences of the pair (QJ) of diamond honors does not change the mechanism, however. At least it looks like a "standard" if a bit warp vise squeeze.

I'm not sure I agree with this taxonomy. In a vice squeeze, the hand with the vice menace takes the last trick, and the squeezee is the one with the two middle honors (QJ in the Reese examples). This looks more like the outcome of a secret experiment in Fred's hand lab where a vice squeeze was crossed with a stepping stone.

Anyway, since the ending has now been alluded to, the winning line is to draw trumps and ruff two spades in dummy and two clubs in hand cashing the high clubs along the way pitching diamonds, and ending up in hand, then cashing the SA. This strips LHO of everything but diamonds.

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Cashing the last trump squeezes RHO down to stiff DQ, now the DK pins the Q and LHO has to give you the DJ at trick 13.

[nige1]

pclayton, on Jul 3 2008, 10:28 AM, said:

Dealer: North Vul: ???? Scoring: IMP

♠   ♥ KJ43 ♦ J983 ♣ AKQ74 ♠ A652 ♥ AQ862 ♦ K72 ♣ 9

You reach a decent 6♥ after pard shows you a mini-splinter in spades. LHO leads the ♣J. Plan the play.

IMO win ♣AKQ. If they stand up lead a 4th ♣, ruffing if RHO shows out, otherwise discarding ♦K. When RHO ruffs the 3rd ♣, over-ruff, ruff a ♠ and lead to ♦K. Unlucky
I agree that Terence Reese would have called the successful line a vice squeeze

[inquiry]

Mechanistically, this is functionally identical to a vice squeeze. A prototypical vice squeeze ending is this....

South leads the ♠A, and WEST has to keep the CLUB ACE, so his QJ of diamonds are "Squeezed" in a vice), I guess the KT of diamonds being the vise. Once he throws a diamond, a diamond is lead and the ♦ten set up.The club and diamond 2 can be placed in the opposite hands and the squeeze works as well.

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The ending phil shows has the same general property and behavior, except there placement of the winners are reversed, the squeeze hand does not hold a "tenace" in the vice suit. (see ending posted by xcurt). If Terrence was to name this, I have no doubt he would think of some clever name for it, maybe "smother squeeze", but if you are going to remember it, perhaps just catagorizing it as a variant of a vice (vise) squeeze will be best.

BTW, if one visualizes a possible ending like this (one hand long in clubs -- one hand long in spades) and wanted to keep this ending in play (along with diamond up to king) you have to time everything carefully so you know if ok to throw a spade or a diamond. There is also a small transportation problem to manage this ending, that might be difficult to see dealing with where you win the second round of trumps if you play them immediately or the second round of trumps if you win the first one in hand and ruff a small spade.

[nige1]

I hope that
Inquiry doesn't mind me pointing out a small typo:
For the vice squeeze to work, swap ♣2 with ♦3.
As in A on the left.

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I hope that
Inquiry doesn't mind me pointing out a small typo:
For the vice squeeze to work, swap ♣2 with ♦3.
As in A on the left.

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I hope that
Inquiry doesn't mind me pointing out a small typo:
For the vice squeeze to work, swap ♣2 with ♦3.
As in A on the left.

---

[xcurt]

ceeb, on Jul 4 2008, 08:31 AM, said:

Hence as a farmer estimate, since the club break is >50%, better to settle for that than to swap part of that big slice for a similar share of a smaller slice.

Checking this using the following dealer code:

predeal
        north HKJ43, DJ983, CAKQ74
        south SA652, HAQ862, DK72, C9

west_minor_cards = (clubs(west) + diamonds(west))
east_black_cards = (clubs(east) + spades(east))

west_follows = west_minor_cards > 5
east_follows = east_black_cards > 6

c_break = (clubs(west) == 3 or clubs(west) == 4)

crossruff_works = c_break && west_follows && east_follows


action
        average "xruff makes" crossruff_works,
        average "c don't break" (!c_break),
        average "west overruffs" c_break && ! west_follows,
        average "east overruffs" c_break && ! east_follows

suggests that the two lines are pretty similar in the absence of inferences from the auction, play, or table action. In one run I got these results. I admit there are a lot of edge cases.

xruff makes: 0.48907
c don't break: 0.3783
west overruffs: 0.10685
east overruffs: 0.0536

It's interesting to see how all the chances of bad breaks combine to really bleed the crossruff line by 16%. Worth keeping in mind next time you bid a thin game or slam that needs good breaks in the secondary offsuits (here spades and diamonds).

EDIT -- the pulling trumps line comes out at 51.3%, which is understandable because the club and heart breaks are going to be positively correlated.

[nige1]

xcurt, on Jul 6 2008, 04:39 PM, said:

predeal
        north HKJ43, DJ983, CAKQ74
        south SA652, HAQ862, DK72, C9

west_minor_cards = (clubs(west) + diamonds(west))
east_black_cards = (clubs(east) + spades(east))

west_follows = west_minor_cards > 5
east_follows = east_black_cards > 6

c_break = (clubs(west) == 3 or clubs(west) == 4)

crossruff_works = c_break && west_follows && east_follows


action
        average "xruff makes" crossruff_works,
        average "c don't break" (!c_break),
        average "west overruffs" c_break && ! west_follows,
        average "east overruffs" c_break && ! east_follows

Wow! Fascinating XCURT! Thank you!
What program executes that script?
The result seems intuitively reasonable but a detail is confusing
Are c_break, west_follows, and east_follows independent?