Newsletter for 24 August 2004

Let's have Backgammon in the Beijing Games in 2008!

On Tuesday, 24 August 2004, the Backgammon Club of San Diego met. Gold, silver, and bronze were awarded to the top finishers.

Tournament News

13 people entered a 16-player main tournament and an 8-player overflow tournament on Tuesday night, our second best showing of the year. We had the following tournament results:

Main Tournament (16 player bracket)

Gold Medal:    Tom Fahland
Silver Medal:  Adrian Costa
Bronze Medal:  Jason Lee

Overflow Tournament (8 player bracket)

Gold Medal:    Sho Sengoku
Silver Medal:  Henry Chaboki

We had an outstanding showing of newcomers. The BCSD welcomed Natan Fisher, Ken Lavinga, and Larry Thomas to the club. Jeannette Consoli also played for the first time in a while. Welcome to the club, all!

Current Master Points Standings

 1. Sho Sengoku      88
 2. Jason Lee        62
 2. Bruce Haight     62
 4. Tom Fahland      57
 5. Adrian Costa     53
 6. Osman Guner      37
 7. Fred Kamgar      35
 8. Eric Sedehi      25
 9. Cyrus Mobedshahi 18
10. Henry Chaboki    14
11. Bruce Discher    10
12. Mark Weiner       9
12. Marcia Karen      9
14. Ryan Knowles      8
14. Ned Cross         8
16. Kismet Hancer     6
16. Greg Kopp         6
18. Vito Volpetti     4
19. Chris Rosin       3
20. Maira Costa       1
20. Sam Mehri         1

Jason Lee moved into a second place tie with Bruce Haight, and Tom Fahland moved into 4th place.

The point leader at the end of the year will be named the BCSD Player of the Year, and the top 16 in the Master Point standings will be invited to the 2004 BCSD Tournament of Champions, to be held in early 2005.

Problem of the Week

+-24-23-22-21-20-19-+---+-18-17-16-15-14-13-+

+--1--2--3--4--5--6-+---+--7--8--9-10-11-12-+

Match to 11, tied 0-0. Pip counts: White 183, Black 158
Position ID: bDsAwGrYXQgsKA Match ID: UwlgAQAAAAAA

Last Week's Problem of the Week

From a BCSD tournament match between Jason Lee (White) and Adrian Costa (Black):

+-24-23-22-21-20-19-+---+-18-17-16-15-14-13-+

| |

| | | |

| |

| 2 |

+--1--2--3--4--5--6-+---+--7--8--9-10-11-12-+

Black leads 3-1 in a match to 7. Pip counts: White 116, Black 113
Position ID: i9sGGBBstw0ABg Match ID: UQngABAAGAAA

White needs 19% to take this cube. There are a couple of ways that White can win this. If Black does not immediately roll a 5 or a 6 (20 numbers), the two checkers behind White's 4-prime will be stuck, and Black will likely have to bust up his full prime. Another way is that Black could roll a 5 or 6 right away, but get hit again immediately thanks to the two checkers on the 9-point, sometimes getting forced deeper. There's a good chance that Black will not be able to hold the full prime forever.

A rollout shows that the decision is fairly close on both ends of the table.

Cube decision

Rollout cubeless equity +0.955 (Money: +0.884)

Cubeful equities:

1. No double +1.022

2. Double, take +1.026 +0.004

3. Double, pass +1.000 -0.022

Proper cube action: Too good to redouble, pass (83.7%)

Rollout details

Win W g W bg Lose L g L bg Cubeless Cubeful

Player Black owns 2-cube 0.804 0.314 0.008 - 0.196 0.045 0.001 +0.955 +1.022

Standard error 0.002 0.002 0.000 - 0.002 0.001 0.000 0.005 0.005

Player White owns 4-cube 0.806 0.320 0.014 - 0.194 0.045 0.001 +1.434 +1.026

Standard error 0.002 0.003 0.000 - 0.002 0.001 0.000 0.009 0.012

Truncated cubeful rollout (depth 11) with var.redn.

1296 games, Mersenne Twister dice gen. with seed 1093557248 and quasi-random dice

Play: 2-ply cubeful 50% speed

keep the first 0 0-ply moves and up to 8 more moves within equity 0.16

Skip pruning for 1-ply moves.

Cube: 2-ply cubeful 33% speed

See you next week! Keep tossing those cubes,
J. Lee

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