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NABC Individual: Do Robots Dream of Endplay?
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You are playing in the North American Bridge Championships Online Individual tournament. That's you with a robot partner and two robot opponents at your table competing against other humans in the same situation. The robots' system is 2/1 Game Forcing. You have decided in advance that your strategy will be to play your regular game.

This event and one of its practice tourneys are your first experiences playing with robots. Some of your friends have said: "These aren't the robots you're looking for." But you figure it could be better than playing your hands solo.

On board 24 of day 1 you bid to a routine contract:

North
A96
J543
AQ5
842
South
K82
AQ1087
K3
A103
W
N
E
S
P
P
P
1NT
P
2
P
3
P
4
P
P
P

West, Left Hand Robot (LHR), leads the 4. Plan the play in detail at matchpoints.

North
A96
J543
AQ5
842
South
K82
AQ1087
K3
A103
W
N
E
S
P
P
P
1NT
P
2
P
3
P
4
P
P
P

West, Left Hand Robot (LHR), leads the 4.

In this normal contract one obvious approach for overtricks is to try to engineer an endplay. Spades can be eliminated using the A entry to ruff the third round. What club holdings offer chances of an overtrick?

These holdings consist of singleton and doubleton honors. This is most evident when the honor is the K. An interesting holding is Jx with West. In this case East may split its honors when a club is lead from dummy. If West does not unblock its J under the A then West is endplayed when thrown in and East cannot overtake. Leading toward the A may also catch East off guard with respect to rising with Kx.

Regarding pulling trump, riding the J makes 5 easily when East has the K. However, the J is the only potential trump entry. In addition, if East has the K962 then the A is a necessary entry to pickup the 9.  Clearly, the communications are complicated.

Can you do it all: pull trump, eliminate spades, and start clubs from dummy? Should you start hearts by leading the 3 or the J?

{begin star trek interlude

Enterprise: Humor alert!  Humor alert!

Kirk: What is it Mr. Spock?

Spock: Bridge playing robots.

Kirk: Bones?

McCoy: I'm a doctor, not a bridge player!

Spock: (Raises eyebrow).

Kirk: What are the odds, Spock?

Spock: Astronomical, Captain.

end star trek interlude}

North
A96
J543
AQ5
842
South
K82
AQ1087
K3
A103
W
N
E
S
P
P
P
1NT
P
2
P
3
P
4
P
P
P
West, Left Hand Robot (LHR), leads the 4.

To gauge your grand unified theory of pulling trump, eliminating spades, and starting clubs from dummy you calculate some odds.

Focusing only on the heart splits, starting hearts by leading the 3 instead of the J gains (i.e., preserves the J as a late round entry to lead clubs) when the K is singleton, when West has Kx, and when West has Kxx (if the K is not held up). In contrast, riding the J initially gains when East has K962 (since that holding can be picked up) and when East has Kxx (since the A is preserved as a late round entry to eliminate spades). In terms of a priori probabilities that is 32.5% to 51.25% (depending on the Kxx duck) for the 3 start versus 23.75% for the J start.

What about unfriendly distributions of the non heart suits? The robots preempt soundly and lead 4th best. Given the 3 opening passes, long spade and club suits can be discounted. Singleton 4 or doubleton 42 in the East is possible, but otherwise diamonds appear to be 5-3 or 4-4.

You decide it isn't batty to risk running on this blade's edge. Let's see the movie.

West
Q753
K2
J9842
J6
North
A96
J543
AQ5
842
East
J104
96
1076
KQ975
South
K82
AQ1087
K3
A103
W
N
E
S
P
P
P
1NT
P
2
P
3
P
4
P
P
P
D
4 South
NS: 0 EW: 0
4
A
6
3
1
1
0
3
6
10
K
0
1
1
J
5
10
K
3
2
1
A
2
4
9
3
3
1
K
5
6
4
3
4
1
8
3
A
J
1
5
1
Q
7
2
8
1
6
1
9
10
Q
7
3
7
1
8
9
J
5
1
8
1
4
Q
A
6
3
9
1
3
J
2
7
0
9
2
Q
5
9
10
1
10
2
8
K
7
2
3
11
2
N/S +450
13

+450 is a top! Out of 26 tables, 24 tables were in 4S.  Making 4 garners 54%.

Here is the traveller.

{begin author interlude

For the record I did not make 5. I lead the J at trick 2 and later ducked a club in preparation for a black suit squeeze which did not materialize. But i do dream of endplays. Am i a robot?Undecided

end author interlude}

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