BBO Discussion Forums: Finesse or endplay? - BBO Discussion Forums

This hand came up 2 weeks ago in a county match. You are playing imps, and despite the large number of points, slam is far from guaranteed. Despite the lack of ruffing values, the 4-4 fit looks to give you more options than NT, so let's assume you are in 6♠. Fortunately trumps break 3-2. How will you play the diamond suit?

Fast forward to last night, and another imp match:

34 points again. The same choice between 6♠ and 6N. And what looks like exactly the same choice in the play! How will you play the club suit this time? Once again it looks like playing the suit contract is more flexible than NT, despite the lack of ruffing values - certainly food for thought there. But surely the odds are against me seeing a similar hand again in my lifetime.

Assuming the basic line of play is: (a) draw three rounds of trumps and (b) cash all winners in the side suits (ending in the right hand), we have two options:

1. Play King to be over the Queen.
-- You will go down on all 3-3 splits provided opponent correctly covers the Queen with the King
-- You will also go down on 26 of 40 combinations of a 4-2 split.
In your first example, playing this way only succeeds if West holds exactly KJxx (6 combinations), KTxx (6 combinations), KJ OR K10 stiff (2 combinations).

2. Play King to be onside.
-- In addition to the 50% chance of finding the King onside, you also succeed when the King is doubleton offside.

Option 2 is clearly superior. Leading the Queen will not win in the long run.

Am I missing anything?

shyams, on 2016-October-25, 04:58, said:

The alternative I was thinking of was not leading the Q, but leading towards it and inserting the 9 if 2nd hand plays low. Now 4th hand will be endplayed to lead away from the K if he has it.

WellSpyder, on 2016-October-25, 05:01, said:

Of course I need coffee!

This post has been edited by nige1: 2016-October-26, 22:27

I'll just lead the ace and play towards the queen on both occasions unless the onside hand is known to be short in the suit. Works any time the king is onside, plus you are making it with K(x) offside anyway.

Take in all the information you can to find out about the opponent's distributions when stripping the hand. If there's any lopsided breaks outside of the trump suit that may favor the ♦ K being in one of the opponents hands.

If you do decide to go for ♦ K onside, then definitely cash the ♦ A before leading toward the ♦ Q. Playing the A caters to a couple additional minor possible holdings that increase the chance of making by a little -- a stiff ♦ K or ♦ J10 doubleton in front of the ♦ Q.

meh play problems without an opening lead. Any difference if it was a diamond?

rmnka447, on 2016-October-25, 06:23, said:

Good point - and one of the key advantages of playing in 6♠ rather than 6NT since you are not risking setting up additional winners for the defence. On the first hand you will find West has 3♠, 5♥ and at least 2♣. On the second hand you will find West has 2♠, 5♦ and at least 3♥.

billw55, on 2016-October-25, 06:33, said:

Fair point. The first hand was played 12 times (some in 6NT, the majority in 6♠ and once in 6♥!), and not surprisingly the lead varied. No-one got a diamond lead, though! I think the most common lead was ♠J. The second hand was played 4 times, half in spades and half in NT, and again I think ♠J was the most common lead.

Everybody has made very good points; my inclination would have been to strip the hand and play Ace and lead toward the Queen winning on king onside or stiff or doubleton king.

However, you do get to somewhat count the hand. If there's an implication that East has four or more clubs on hand 2, you strip the hand, making sure you win the last card in South. Then, since East can't have a doubleton king and is more likely to have the king, you lead low to the 9. What an interesting dilemma if West sticks in a minor honor!

As long as you cash the hearts last, you are automatically in the correct hand to lead low to the D9 on hand 1 should West prove to have the diamond length by your count. I'll ponder what I'd do if second hand played the ten or jack, but posting this now will let others ponder the same thing.

EDIT to add: On problem 2, if the count says East has long clubs and West plays the CJ or C10 when I lead toward the dummy, I'll play the queen on the basis that West might have led the CJ from C-JTx.

On the first hand, if East plays the D10 or DJ; I'll play the queen, paying off to J10 doubleton; also if my count implied West might be longer or they are 3-3, the queen wins when the king was onside all the time.

WellSpyder, on 2016-October-25, 07:29, said:

The distribution information that was obtained will help you adjust the probabilities that either player holds the ♦ K by using "vacant places".

In the 1st hand, with West holding 8 cards in suits whose distribution is completely known, there are 5 "vacant places" which can have any combination of cards in the remaining suits. Likewise, East must hold only 3 cards in these suits, so East has 10 vacant places. The likelihood that any particular card is held is in proportion to the number of vacant places in each hand. So East is 2 to 1 to hold the ♦ K which favors the finesse. Conversely, if the opponents' hands were swapped, West would be a big favorite to hold the ♦ K. So, in that case, the endplay is a big favorite.

A terrific book on this topic is Hugh Kelsey & Michael Glaubert's Bridge Odds for Practical Players.
It was first published back in 1980 as part of the Master Bridge series, which is when I got my copy. If you can find a copy, it is an excellent fundamental guide to calculating probabilities to help decide what do with bridge hands. I heartily recommend it to intermediates and advanced players who could use some help in this area.


Edit note - It looks like the book is out of print for some time and only available through the used book aftermarket.

Kaitlyn S, on 2016-October-25, 10:45, said:

Well done - some excellent points, and it looks like you would have made hand 2, which none of the 4 declarers managed on the night. The count does indeed reveal that East is likely to be longer in clubs, and in practice he had all 3 honours, so you wouldn't face the dilemma of what to do if 2nd hand plays a minor honour. (Of course the two declarers in 6N didn't have the luxury of getting a count quite so easily.)

On the first hand, any count inferences you might get are a bit misleading since you don't get a count of the club suit, which on the actual hand offsets the imbalances in the other suits. If I tell you that diamonds are 3-3, what is the best way to play the suit? Can one of our game theory experts explain what 2nd hand should play with KJx, K10x, J10x, Jxx or 10xx?