The Decisions that Decided the Tournament
 

Final of the Masters in Paris

3rd 11-point match

Levermann (7) Kahn (1)

(White) (Black) 

White owns the 4-cube.

White to play 6-2.

 
White has to cover on the 3-point (5/3) with the deuce. He has a five point board now.

What is Whiteīs game plan now?

He has to close out Blackīs checker to have the insurence that he can clear the opponentīs bar point without getting attacked. In the moment White has no closed board. Therefore he doesnīt want to leave the opponentīs bar point as long as he has one checker back. White needs a checker to play with by keeping the bar-point. Therefore he should bring his back checker to the bar-point (24/18).

If White plays 8/2, he often has to leave the opponentīs bar-point with his next roll, has to expose blots and his back checker in the opponentīs board.

Best play: 5/3 24/18.

What happened in the match? - Levermann closed out Kahnīs back checker, but didnīt succeed in bringing his back checker home because he played 5/3 8/2. He has to crunch his board down to three points and lost the game. Later, after a 10-5 Crawford lead Levermann lost the match and Donald Kahn won the Masters.

Final of the Championship in Paris

21-point match

Levermann (11) Sequeira (5)

(Black) (White)

White owns the 2-cube.

White on roll.

Cube action?!

 
White is able to win only 52% of the games. Most of the time these winning chances are not sufficient to justify a redouble. However, trailing the match by 5-11 and the ability to win a gammon in 29% of the games make a redouble marginally correct.

Mario Sequeira correctly redoubled and Johannes Levermann correctly took the cube and lost a gammon.

The Protuguese took a 13-11 lead, but Johannes Levermann succeeded in regaining the lead a few games later.

Final of the Championship in Paris

21-point match

Levermann (17) Sequeira (15)

(Black) (White)

White to play 5-1.
White is a clear favorite to win this game. 22/16 solves Whiteīs main problems of escaping with his back checkers. Therefore the play 22/16 by winning over 7% more games than 7/1 (the best alternative), is clearly best at double match point.

But this checker play problem is not that easy to solve. The cube is in the middle. If Black dances, White has a double out if he played 22/16 and a double in if he played 7/1.

Therefore it is possible, that increasing Blackīs dancing numbers by 7/1 could be better than losing the market by 22/16 and a dance by Black.

A precise calculation will show whatīs best:
 


Roll

 

Play / Action

Match winning chances -

White played 7/1


Play / Action

Match winning chances -

White played 22/16

1/1:

Dancing / Double - take

39.22%

Bar/24* 24/23 17/16 6/5

33.37%

2/1:

Bar/23 17/16

37.12%

Bar/24* 17/15

35.65%

3/1:

Dancing / Double - take

39.22%

Bar/24* 6/3*

34.77%

4/1:

Dancing / Double - take

39.22%

Bar/24* 7/3*

34.78%

5/1:

Dancing / Double - take

39.22%

Bar/24* 8/3*

34.65%

6/1:

Dancing / Double - take

39.22%

Bar/24* 17/11

36.56%

2/2:

Bar/23 17/11

36.13%

Bar/23 17/15 2x(5/3)*

34.79%

3/2:

Bar/23 17/14

36.20%

Bar/23 6/3*

37.36%

4/2:

Bar/23 17/13

36.94%

Bar/23 7/3*

37.68%

5/2:

Bar/18*

30.27%

Bar/23 8/3*

38.20%

6/2:

Bar/17

32.59%

Bar/17

34.34%

3/3:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

4/3:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

5/3:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

6/3:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

4/4:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

5/4:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

6/4:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

5/5:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

6/5:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

6/6:

Dancing / Double - take

39.22%

Dancing / Double - Pass

42.67%

 

 

 

 

 

Σ

 

1362,87 %

 

1398,86 %

 

The numbers show that 22/16 results in the higher match winning chances also at the actual match score.
Mario Sequeira covered by 7/1 and doubled Levermann (after a dance) in.
He scored a gammon win (4 points) and later won the match by winning the double match point game.

It was a nice weekend for the Sequeiras, because Marioīs wife also succeeded in winning her division (the Intermediate flight). But I think it was a nice weekend for all of us who like backgammon, because we had a lot of the drug we like!

 

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