Play problem

[Lorne Anderson]

Teams scoring, no oppo bidding, you get to 4S with:

9873
AK82
A1083
8

AQ106
J
KQ4
97432

A very good player thinks I got this wrong but I am not sure so I
thought I would test it with you. Nobody objected to the early play so
I stick you with that:

2D lead, 10 wins and you play a club.
LHO wins and plays 6H, you win and play a spade to 10 & J.
7H played (probably MUD) so you win and play a trump.
RHO produces the 4+5 of trumps at this stage.

Do you rise A or finesse?

[Dave Flower]

Post by Lorne Anderson
9873
AK82
A1083
8
AQ106
J
KQ4
97432
A very good player thinks I got this wrong but I am not sure so I
thought I would test it with you. Nobody objected to the early play so
2D lead, 10 wins and you play a club.
LHO wins and plays 6H, you win and play a spade to 10 & J.
7H played (probably MUD) so you win and play a trump.
RHO produces the 4+5 of trumps at this stage.
Do you rise A or finesse?

Well, I don't get to that position - when I win the top heart, I play a diamond to hand, ruff a cub, ditch a diamond on the HA, and lead DA. If RHO ruffs, I overruff and ruff another club; otherwise, I discard a club and ruff a heart.
Should be able to get three club ruffs in dummy.

Dave Flower

[Lorne Anderson]

Post by Dave Flower

Post by Lorne Anderson
9873
AK82
A1083
8
AQ106
J
KQ4
97432
A very good player thinks I got this wrong but I am not sure so I
thought I would test it with you. Nobody objected to the early play so
2D lead, 10 wins and you play a club.
LHO wins and plays 6H, you win and play a spade to 10 & J.
7H played (probably MUD) so you win and play a trump.
RHO produces the 4+5 of trumps at this stage.
Do you rise A or finesse?

Well, I don't get to that position - when I win the top heart, I play a diamond to hand, ruff a cub, ditch a diamond on the HA, and lead DA. If RHO ruffs, I overruff and ruff another club; otherwise, I discard a club and ruff a heart.
Should be able to get three club ruffs in dummy.
Dave Flower

I think you need the clubs 4-3 (62%) for this to work, especially if the
diamonds are 4-2 which the lead suggests.

[Travis Crump]

Post by Lorne Anderson
9873
AK82
A1083
8
AQ106
J
KQ4
97432
A very good player thinks I got this wrong but I am not sure so I
thought I would test it with you. Nobody objected to the early play so
2D lead, 10 wins and you play a club.
LHO wins and plays 6H, you win and play a spade to 10 & J.
7H played (probably MUD) so you win and play a trump.
RHO produces the 4+5 of trumps at this stage.
Do you rise A or finesse?

Why did I finesse the ST earlier if I don't intend to finesse now? I
don't see how finessing the T helps unless you intend to take out three
rounds of trump which seems awkward. I would have finessed the SQ, taken
out two rounds of trump win/lose, and then go about my business
unblocking diamonds and ruffing clubs.

[Robert Chance]

Post by Lorne Anderson
Do you rise A or finesse?

Rising with the ace guarantees the contract against any holding other than singleton jack offside (you discard two clubs on red suit winners and ruff the other two, and the defence will take the king of trumps at some point). OTOH, finessing loses when LHO has KJ or KJx. That's far more likely than a singleton jack.

I also suspect that there may be some holdings where you go down if LHO has a singleton jack even if you do finesse at this stage. The analysis is quite complex here - way beyond what most of us would be capable of at the table - but I think you are always down if RHO is 4522 shape, for example.

So going up with the ace seems to me to be better by a country mile.

I agree with Travis, however - I think you would have been better off finessing the queen first. This gives you a better chance of an overtrick (and a very slightly better chance of making the contract).

Incidentally, unless LHO could have led the two of diamonds from xxx, I think you are better off winning the first diamond in hand.

[Lorne Anderson]

Post by Robert Chance

Post by Lorne Anderson
Do you rise A or finesse?

OTOH, finessing loses when LHO has KJ or KJx.
That's far more likely than a singleton jack.

Does not lose to KJ as they can't play a 3rd trump or overruff dummy.
Will lose to KJx if they play a 3rd trump (and they usually will).

So I think it comes down to 75% chance for the finesse + the KJ
doubletons - some 4-1 distributions when they can ruff your diamonds
against 68% chance for trumps 3-2.

Post by Robert Chance
Incidentally, unless LHO could have led the two of diamonds from xxx,
I think you are better off winning the first diamond in hand.

I worked that out at about trick 4 which was a bit late !

[Robert Chance]

Post by Lorne Anderson
Does not lose to KJ as they can't play a 3rd trump or overruff dummy.
Will lose to KJx if they play a 3rd trump (and they usually will).
So I think it comes down to 75% chance for the finesse + the KJ
doubletons - some 4-1 distributions when they can ruff your diamonds
against 68% chance for trumps 3-2.

If you finesse and lose to KJ doubleton, you will go down - if diamonds are 4-2 you can't ruff two clubs and get back to hand to draw the final trump. If diamonds are 3-3, you can get back to hand to draw the final trump, but you will be stuck in hand at trick 13 with a losing club. Similarly, if LHO has KJx then you will go down even if LHO fails to return a trump.

You're miscalculating the odds of the various options. Going up with the Ace only loses when LHO is now void in spades. Finessing loses when LHO now has Kx or singleton king. The finesse is 50% at this stage, not 75%, as we already know that West began with the jack. (This is a difference between a double finesse for the KJ and a double finesse for the KQ). And, as we have already seen, you may not be home even if the finesse succeeds.

So finessing is less than 50%, whereas going up with the ace wins whenever trumps break 3-2. There is no particular reason to think the trumps are less likely to break now than there was at the beginning of the hand, so going up with the ace is about 84% (we already know East does not have a singleton).

[Lorne Anderson]

Post by Robert Chance
The finesse is 50% at this
stage, not 75%, as we already know that West began with the jack.
(This is a difference between a double finesse for the KJ and a
double finesse for the KQ). And, as we have already seen, you may
not be home even if the finesse succeeds.

Looks like I screwed up. I was convinced it was 75% at the time but
forgot the KJ are not touching.

[Dave Flower]

Post by Lorne Anderson

Post by Robert Chance
The finesse is 50% at this
stage, not 75%, as we already know that West began with the jack.
(This is a difference between a double finesse for the KJ and a
double finesse for the KQ). And, as we have already seen, you may
not be home even if the finesse succeeds.

Looks like I screwed up. I was convinced it was 75% at the time but
forgot the KJ are not touching.

What was the full hand? I am interested on how my suggestion of playing on cross-ruff lines would have worked

Dave Flower

[Lorne Anderson]

Post by Dave Flower

Post by Lorne Anderson

Post by Robert Chance
The finesse is 50% at this
stage, not 75%, as we already know that West began with the jack.
(This is a difference between a double finesse for the KJ and a
double finesse for the KQ). And, as we have already seen, you may
not be home even if the finesse succeeds.

Looks like I screwed up. I was convinced it was 75% at the time but
forgot the KJ are not touching.

What was the full hand? I am interested on how my suggestion of playing on cross-ruff lines would have worked
Dave Flower

You probably make because the clubs are 4-3, but not sure it is the best
line:

9873
AK82
A1083
8
KJ2 54
764 Q10953
J92 765
AQJ5 K106
AQ106
J
KQ4
97432

[Charles Brenner]

Post by Lorne Anderson

Post by Robert Chance

Post by Lorne Anderson
Do you rise A or finesse?

OTOH, finessing loses when LHO has KJ or KJx.
That's far more likely than a singleton jack.

Does not lose to KJ as they can't play a 3rd trump or overruff dummy.
Will lose to KJx if they play a 3rd trump (and they usually will).

I'm stumped. Regardless what we discarded on the hK and regardless whether we now play the trump Q or the 6, if it loses to the K we are we not virtually certainly down? And if it wins we have probably gained nothing.

Suppose it loses. While West is thinking, we count 6 red tricks if and only if we can cash all 4 diamonds. So we definitely need 4 trumps tricks. So far we have none, and only 4 trumps remain between our two hands. We must somehow score all four of those and cash the last diamond as well.

No way we can ruff twice in one hand, pull trumps, and *then* cash the last diamond. So the only winning possibility is to cash all the diamonds with a trump remaining out. From the opening lead it is virtually certain that East will not follow four times to diamonds, so if the finesse loses to West's KJ doubleton we are down. And as you say with KJx of trump West can easily count that a trump return beats the hand.

So if trumps are breaking, the finesse never gains and it loses the contract whenever it loses.

If RHO had 4 trumps, Robert suggests finessing likely works but I don't see it. We still would need 4 trumps -- so a club ruff in dummy. Unless a minor suit squeeze eventuates that compensates for the diamond blockage, we're just down. Only if LHO is exactly 1345 does the finesse gain.

Post by Lorne Anderson
So I think it comes down to 75% chance for the finesse

The sK finesse was 50% at the start of the hand and losing to the J did not change that.

[Charles Brenner]

If RHO had 4 trumps,... Only if LHO is exactly 1345 does the finesse gain.

or if diamonds are 3-3; I overlooked that. So the finesse gains also when LHO is 1435, 1534, or 1633. Not often.