[roghog]

Scoring: IMP

1♦ - 1NT
2♣ - 2♦
4♦ - 4♥
5♥ - 6♣

1NT = artificial GF
2♦ relay for shape
4♦ 2074 plus 5 controls (AAK/AKKK)
4♥ relay for tops (AKQ)
5♥ 2 in ♦ + 1 in ♣ + 1 in ♠

Lead : Q♣

---

So, folks, you play K♣ and continue with another to the A, West discarding a ♥.
Then a low ♦, ruffing in dummy.
Next a ♠ to the K, and another ♦, ruffed and overruffed. (Aaargh!)
Low ♥ from East, taken by dummy's A.
You play A♠, on which West's 10 appears. East plays low on the J.

(1) Does this line seem OK to you?
(2) Will you now play for ♠ to be 3-3, or try a ruffing finesse against the Q?
(Perhaps someone can estimate the odds in the ♠ suit for me.)

[han]

So it's Q10x vs 10x, same number of holdings. Given that lefty has 6 minor suit cards and righty 4 the calculator at www.rpbridge.net tells us that 4-2 is now more likely than 3-3 by 2.2 to 1.82. I think.

[Echognome]

I want to think about it some more, but I think I would have played on dummy reversal lines. We two 7 card side-suits, so there is no real advantage of setting up one or the other. It feels like it is easier to keep control setting up dummy with the long trumps. I would take the ♣A in hand. Play the ♦A (throwing a heart), then play ♠K, ♠A, and ruff a spade. Then I would attempt to ruff a diamond in dummy. I might be off now with the overruff and trump back, but I believe this is the line I would play.

[han]

You call it dummy reversal even if dummy has more trumps?

(Serious question, I always considered a dummy reversal as ruffing in the hand with long trumps, independent of which hand is dummy.)

[Fluffy]

agree with Han, that is not dummy reversal IMO

[Trumpace]

Perhaps West's inability to bid over 1♦ makes a case for 3-3 split?

With a 2-5-5-1 hand with ♦KJT and at least on heart honour and the ♣Q, W might have bid over 1♦?

Anyway, ignoring the bidding and going with odds, ruffing finesse seems more likely (given East's low heart lead, it looks like W will hold a heart honour, so that skews the odds a little {from the values in Han's post} , but i don't think it does by much).


Your line seems pretty reasonable roghog...

[Echognome]

Fluffy, on Oct 18 2007, 01:33 PM, said:

agree with Han, that is not dummy reversal IMO

I call it a "dummy reversal" because I am setting up dummy rather than declarer's hand. That is my intent, even if you disagree with the nomenclature.

[han]

Yeah, only talking about the nome.. about what the word means.

[cherdano]

Hannie, on Oct 18 2007, 04:43 PM, said:

Yeah, only talking about the nome.. about what the word means.

It is spelled "gnome".

[roghog]

Hannie, on Oct 18 2007, 10:13 PM, said:

So it's Q10x vs 10x, same number of holdings. Given that lefty has 6 minor suit cards and righty 4 the calculator at www.rpbridge.net tells us that 4-2 is now more likely than 3-3 by 2.2 to 1.82. I think.

Thanks, Hannie, but...

I've heard this logic before, but I'm confused by the maths. LHO is either 2-5-5-1 or 3-4-5-1. RHO is either 4-5-1-3 or 3-6-1-3. Because LHO has 2 more minor cards than RHO, LHO is less likely to hold a third ♠. But, by the same logic, LHO should also be less likely to hold a 5th ♥.

Can some kind mathematician explain??

[Trumpace]

I am probably not the kind of mathematician you expected, but here is what i understand (which might be wrong...)

The fact that LHO holds at least 4 hearts or that RHO holds at least 5 hearts is not new information to you. You always knew that, given the information you have so far (minor suit break + spade split upto now). So there is no need to take that information into account when calculating the odds. Check out Richard Pavlicek's article titled "How percentages change": http://www.rpbridge.net/7z75.htm.

In calculating the likelihood of LHO holding the SQ, the number of vacant spaces you need to count is still 5 (13 minus 2 spades, 5 diamonds and 1 club) and for RHO it is still 6 (13 minus 3 spades, 1 diamond and 3 clubs)*. The fact that you know LHO has at least 4 hearts is irrelevant (as it is not new information), as no matter how you distribute the cards with 5 vacant spaces, it will still be true that LHO has at least 4 hearts. The info that LHO has at least 4 hearts has not eliminated any cases for you...

When you actually count the possible number of holdings of LHO, the number of 2-5-5-1 holdings of LHOs vs number of 3-4-5-1 holdings of LHO is different. In fact the number of possible 2-5-5-1 holdings with LHO is greater than number of possible 3-4-5-1 holdings and that is the reason ruffing finesse is better.

If you want to count the holdings by giving LHO a 4 carder heart first and RHO 5 carder heart, you have to be careful not to double count.

For instance you give four specific hearts to LHO and five specific hearts to RHO. You are now left with the SQ and the 10th heart. The chances that LHO now gets the the 10th heart is 50% is true... but if you consider over all such "specific" holdings, you will double count some of the LHO 5 card heart distributions, which means that chances of LHO holding the 5 carder heart will be smaller than the chances of him holding the Spade Q.

For instance, first you give 3,5,6,7 to LHO and 8,9,T,J,Q to RHO. Now you randomly pick SQ or HK to give to LHO. Say LHO get the K.

Now in another instance, you give LHO, K,7,6,5 and give RHO 8,9,T,J,Q. Now you randomly pick SQ or H3 to give to LHO. If you give LHO the 3, then you end up with the distribution of the previous paragraph...

Basically, the term "the fifth heart" is ambiguous as compared to the "the spade queen".

Hope I have not managed to confuse the topic even further.


* - Note, this assumes that the heart suit cards played by LHO and RHO on the heart trick are equally random (and you forgot to notice them). If they follow some signalling conventions, then the heart spots give you new information which you have to cater to...

[Echognome]

Jlall, on Oct 22 2007, 03:38 PM, said:

btw to me a dummy reversal means ruffing in the long trump hand in order to establish tricks by making the short trump hand the long trump hand (ie one hand has 5 trumps, one hand has 4 trumps, you ruff 3 times in the 5 trump hand to establish 2 extra winners). It has no relation to whether you are setting up dummy or your hand and is called a dummy reversal only because in general (especially pre transfers) the long trump hand is declarer.

Should I pretend to be indignant about the literal words or just admit defeat?

I think I'll choose the latter.

[Winstonm]

My line would have been to try to ruff out diamonds, leaving spades as a second chance. So:
K of clubs
ruff low heart
ruff low diamond
Club to ace
ruff low diamond (over ruff)
heart back to ace, diamond pitch


spade to K
spade (LHO plays 10)

LHO is known to hold 5 diamonds, 2 hearts, 1 club, 2 spades
RHO is known to hold 1 diamond, 2 hearts, 3 clubs.

No mathematician here, but at the table iI looks for shortcuts - here, I am only interested in one card, the spade Q. RHO has 7 open slots to LHO's 3 so I play RHO to hold that card.

In my book, RHO is 7:3 favorite to hold the spade Queen, but if you bet it I'm only offering 5:3 odds.

[Trumpace]

Winstonm, on Oct 22 2007, 08:08 PM, said:

In my book, RHO is 7:3 favorite to hold the spade Queen, but if you bet it I'm only offering 5:3 odds.

I disagree with those odds.

In fact, if this hand had occured at the table, I would probably play LHO to hold 3 spades, because of the (absence of) bidding...