How do the diamonds lie?
(Page of 4)

This hand was written up twice in the second bulletin from the Europeans.  Boye Brogeland found the winning play at the table, while Mark Horton's postmortem writeup suggested the same line.  What would you do?  (Rotated for convenience; you are actually West--this is board 8 from round 1.)

North
K7643
653
A104
106
South
AQ1092
98
J85
AK8
W
N
E
S
1
P
3
X
4
P
P
P

West leads the 2 (third/low).  East takes the A and continues the ten.  West wins the jack and gets out with the king.

Plan the play.

North
K7643
653
A104
106
South
AQ1092
98
J85
AK8
W
N
E
S
1
P
3
X
4
P
P
P

It seems best to ruff, eliminate clubs, draw trump, and attempt to endplay East in diamonds--West's stiff 9 seems very unlikely on the auction and early play.  East discards the 4 on the second spade and follows with the queen on the third club.

When you turn your attention to diamonds, West plays the deuce and East wins the king, then puts you to the guess with the six.

North
76
A4
South
Q10
J8
W
N
E
S
1
P
3
X
4
P
P
P

Do you play the eight or jack?

North
76
A4
South
Q10
J8
W
N
E
S
1
P
3
X
4
P
P
P

You can try to infer East's shape, but that doesn't help--regardless, there is as much room for the queen as for the nine.

There are several reasons to play the eight...

• Restricted choice
• If East's double of hearts is primarily lead-directional, he shouldn't have an equally strong holding in another suit
• If the jack is right, West could have set the hand by force with a diamond switch at trick three

West
85
KJ2
932
J7542
North
K7643
653
A104
106
East
J
AQ1074
KQ76
Q93
South
AQ1092
98
J85
AK8
W
N
E
S
1
P
3
X
4
P
P
P
D
4 South
NS: 0 EW: 0

What Brogeland noticed was East's play of a high heart at trick two, suit preference for diamonds.  With that in mind, he played the jack to bring home his contract.  Fortunately for him, West hadn't drawn the same conclusion.

7 out of 18 declarers in 4 made ten tricks, as did 2 of 8 declarers in partials.  We know that one declarer was faced with an opening diamond lead, making his task hopeless.  We don't know how many others got an early diamond switch from West.