THE 11th ANNUAL WORLD COMPUTER-BRIDGE CHAMPIONSHIP

Shanghai, China

4-9 October 2007

 

by Alvin Levy

 

 

The 11th annual World Computer-Bridge Championship, sponsored by the American Contract Bridge League (ACBL) and the World Bridge Federation (WBF), was held in Shanghai, China alongside the WBF’s 38th World Team Championships.

History

The ACBL inaugurated an annual computer-bridge championship in 1997 as a way of encouraging computer-bridge software developers to accelerate their robots’ development to expert class, with the hopeful result of more software development for educational purposes and generally to promote bridge.  The WBF also supports this event and starting in 1999 it became an ACBL/WBF joint venture.  Since its inception in 1997, the championship has been held every year alongside an important bridge championship.  The eleven championships have been held four times at ACBL North American Bridge Championships, six times at WBF World Championships and once at the European Bridge League’s first European Open Championship.  For a complete history and details of previous championships go to www.computerbridge.com or www.ny-bridge.com/allevy/computerbridge

 

Technical remarks

A bridge “table” consists of a central server (CS) that manages the game, and four connecting computers that “seat” the robots.  The CS distributes the four hands of each board to the robots.  Play proceeds automatically, with pauses for exchanges of information when explanations of bids are necessary.  The CS receives and passes information from and to the robots and records the bidding and play.  This year P4 3 GHz/512 MB PCs were used, running under Windows XP.  Unfortunately the computers where shy of the advertised specifications, which was not an issue for most of the contestants.  The timing of play was set at two minutes per pair per deal.

 

The contestants submit their Convention Card (CC), containing their bidding and carding methods, one month before the competition so that the others can prepare.  This information is stored in the opponent robots’ memories before play begins.  Nevertheless, there are some alerts (explanations) that occur during the bidding and are manually input into memory during play.

 

Without getting into the details, most of the robots are programmed with a combination of knowledge-based AI (sets of rules) and search-based AI (simulations).

 

Play format

The format is team play.  Two teams play each other, with each team using four identical robots, one pair sitting North-South at one table and one pair sitting East-West at the other table.

 

This six-day event starts with a 32-board round-robin, each team playing the other seven.  The top four robot teams advance to the semifinal knockout stage, a 64-board semifinal followed by a 64-board final.  The round-robin is scored on an International 30-VP scale.

 

The competitors

Eight robots entered this year’s championship, including two newcomers RoboBridge and TUT Bridge.  TUT Bridge is a new project at the Computer Science Department of Tokyo University of Technology.  The other contestants are five-time and defending champion Jack, 2005 champion WBridge5, 1997 champion Bridge Baron, 2001 runner-up Micro Bridge, three-time runner-up Q-Plus Bridge and second-year competitor Shark Bridge.

 

Robot

Developers

Country

WBridge5

Yves Costel

France

Jack

Hans Kuijf, Wim Heemskerk and Martin Pattenier

The Netherlands

Bridge Baron

Stephen Smith, Jason Rosenfeld and Tom Throop, Jr.

USA

Q-Plus Bridge

Hans Leber, Gérard Joyez operator

Germany

Micro Bridge

Tomio and Yumiko Uchida

Japan

Shark Bridge

John Norris

Denmark

RoboBridge

Job Scheffers

The Netherlands

TUT Bridge

Takao Uehara

Japan

                        Table 1. Robots and their developers.

 

Results

The round-robin ended with WBridge5 topping the field, followed by Jack, Bridge Baron and Q-Plus Bridge.

 

WBridge5

Jack

Bridge

Baron

Q-Plus

Bridge

Micro

Bridge

Shark

Bridge

Robo-

Bridge

TUT

Bridge

Total

Position

WBridge5

 

IMPs

X

VPs

97-40

24-6

71-71

15-15

64-44

18-12

88-53

21-9

81-81

15-15

144-38

25-0

120-45

25-3

143

1

Jack

40-97

6-24

IMPs

X

VPs

97-29

25-4

67-63

16-14

87-29

24-6

47-16

20-10

96-65

20-10

148-16

25-0

136

2

Bridge

Baron

71-71

15-15

29-97

4-25

IMPs

X

VPs

87-59

19-11

57-33

19-11

106-71

21-9

108-43

25-5

103-33

25-4

128

3

Q-Plus

Bridge

44-64

12-18

63-67

14-16

59-87

11-19

IMPs

X

VPs

52-74

12-18

81-64

18-12

119-50

25-4

117-40

25-3

117

4

Micro

Bridge

53-88

9-21

29-87

6-24

33-57

11-19

74-52

18-12

IMPs

X

VPs

73-41

20-10

112-44

25-4

88-50

21-9

110

5

Shark

Bridge

81-81

15-15

16-47

10-20

71-106

9-21

64-81

12-18

41-73

10-20

IMPs

X

VPs

119-59

25-5

133-24

25-0

106

6

Robo-

Bridge

38-144

0-25

65-96

10-20

43-108

5-25

50-119

4-25

44-112

4-25

59-119

5-25

IMPs

X

VPs

149-52

25-1

53

7

TUT

Bridge

45-120

3-25

16-148

0-25

33-103

4-25

40-117

3-25

50-88

9-21

24-133

0-25

52-149

1-25

IMPs

X

VPs

20

8

 

                        Table 2.  Round Robin results.

 

In the semi-final matches Bridge Baron defeated Jack, 190-153 and WBridge5 defeated Q-Plus Bridge 278-165.  In the final match, WBridge5 defeated Bridge Baron 206-101.

 

WBridge5’s results are impressive, winning six of its eight round-robin matches, tying the other two against finalist Bridge Baron and Shark Bridge, and convincingly winning its semi-final and final matches.

 

The Play

Some of the boards played in the sixth and seventh round-robin matches were played earlier in the “human” championships which are the Bermuda Bowl (Open Team Championship), Venice Cup (Women’s Team Championship), and Senior Bowl (Senior Team Championship).  Two boards from the seventh round follow.  In the round robin of the computer championship each hand was played 8 times, while in the human championships each board was played 22 times.

 

Board 1. Dealer North. None Vulnerable.

 

♠ K 6 5 4 3
♥ J 9
♦ K 4 2
♣ A J 10

♠ 10 7
♥ A Q 8 6 3 2
♦ 3
♣ 7 4 3 2

North

 

West         East

 

South

♠ 9 2
♥ 10 4
♦ A J 8 7 6
♣ K 9 6 5

 

♠ A Q J 8
♥ K 7 5
♦ Q 10 9 5
♣ Q 8

Board 1 is a routine board.  It's used to show that, on flat boards, the robots reach normal contracts and make the normal number of tricks.  In the human championships, 4♠ was reached 63 out of 66 times and 3NT was reached the other three times.  4♠ was made five times, four times with a club lead away from the King, and once on poor defense after the ♥10 lead.  3NT was defeated each time.  The robots reached 4♠ all eight times, with all defeated one or two tricks.  No defender led away from the ♣K.

Board 2. Dealer East. N-S Vulnerable.

 

♠ K Q J 8 7 6 3
♥ 10 7
♦ 6
♣ K 10 2


♠ -
♥ J 8 6 5 2
♦ A K J 8 2
♣ Q 4 3

North

 

West         East

 

South


♠ 9 4
♥ K Q 9 3
♦ 4
♣ J 9 8 7 6 5

 

♠ A 10 5 2
♥ A 4
♦ Q 10 9 7 5 3
♣ A

 

Board 2 is much more interesting.  The robots reached the cold 6♠, or sacrificed in 7♥ 50% of the time, compared to less than 25% of the time for the humans.

 

Bermuda Bowl

Venice Cup

Senior Bowl

Robots

6♠(x)

5/22

3/22

5/22

3/8

7♥x

1/22

0/22

1/22

1/8

 

West

North

East

South

Versace

Chagas

Laurie

Villas Boas

 

 

Pass

1♦

1♥

4♠

5♥

6♠

All Pass

 

 

 

 

West

North

East

South

Versace

Chagas

Laurie

Boas

 

 

Pass

1♦

1♥

2♥ (transfer)

4♥

4♠

All Pass

 

 

 

 

When West overcalled 1♥, either North and/or East-West preempted the auction and North-South had to be less than scientific, as is often the case with preempts.  In the Bermuda Bowl Italy-Brazil match, pitting two of the best teams in the world, Boas for Brazil gambled that there would not be two diamond losers, while Bocchi-Duboin for Italy didn't venture past 4♠.

 

 

West

North

East

South

RoboBridge

WBridge5

RoboBridge

WBridge5

 

 

Pass

1♦

Pass

1♠

Pass

3♠

Pass

4♣

Pass

4♥

Pass

4NT

Pass

5♣ (0-3)

Pass

6♠

All Pass

 

WBridge5 had an excellent auction when RoboBridge passed over 1♦.

 

West

North

East

South

Jack

Micro Bridge

Jack

Micro Bridge

Micro Bridge

Jack

Micro Bridge

Jack

 

 

Pass

1♦

1♥

1♠

3♥

4♠

Pass

4NT

Pass

5♣/5♦ (0-3)

Pass/Dbl

6♠

Pass

Pass

Pass/Dbl

 

 

 

In the Jack-Micro Bridge match, both North robots judged that it was a good bet that South had first or second round control of hearts.  When Jack responded 5♦ to KCB, West doubled for the lead, and then doubled the final contract.  Jack gained 6 IMPs.

Final match

The final match pitted WBridge5 against Bridge Baron.  Throughout the tournament WBridge5’s aggressive bidding resulted in bidding, and making, more slams then its opponents.  In the final match this aggressive bidding paid off.  The final match, between WBridge5 and Bridge Baron, contained twelve boards where one or both sides were in slam.  The result was a net gain for WBridge5 of 109 IMPs, more than the margin of victory.

Two boards from the final match follow.

Board 8, 2nd segment. Dealer West. None Vulnerable.

 

♠ 3
♥ A K 10
♦ A 4
♣ K J 10 8 7 5 4

♠ J 8 6
♥ Q 8 5 4 3 2
♦ K Q 8 2
♣ -

North

 

West         East

 

South

♠ Q 10 5 2
♥ 9 7
♦ J 9 7 5 3
♣ 9 2

 

♠ A K 9 7 4
♥ J 6
♦ 10 6
♣ A Q 6 3

 

West

North

East

South

Bridge Baron

WBridge5

Bridge Baron

WBridge5

Pass

1♣

Pass

1♠

Dbl

3♣

3♦

4NT

Pass

5♣(0 or 3 KCs)

Pass

5NT

Pass

6♦(1 King)

Pass

7♣

All Pass

 

 

 

 

This gained 14 IMPs for WBridge5.  At the other table WBridge5 West opened 2♥, North Doubled, and Bridge Baron South jumped to 4♠ and played it there for +420.

 

 

Board 5, 4th segment. Dealer North. N-S Vulnerable.

 

♠ K Q 6 3
♥ 4
♦ A 8 7 6 3
♣ Q 6 4

♠ 5 4 2
♥ J 10 8 5
♦ 10 9
♣ 7 5 3 2

North

 

West         East

 

South

♠ 10
♥ A Q 9 2
♦ K J 4 2
♣ K 10 9 8

 

♠ A J 9 8 7
♥ K 7 6 3
♦ Q 5
♣ A J

 

West

North

East

South

Bridge Baron

WBridge5

Bridge Baron

WBridge5

 

1♦

Pass

1♠

Pass

2♠

Pass

4♣

Pass

4♦

Pass

4♥

Pass

4♠

Pass

4NT

Pass

5♠ (2 + ♠Q)

Pass

6♠

All Pass

 

 

 

The slam seems impossible and can be defeated on a diamond lead.  Bridge Baron made the normal lead of the ♥J to East's ♥A.  East returned the trump 10, declarer winning the Jack.  The play proceeded ♥K, heart ruff, club finesse, heart ruff, running trumps coming down to a three-card ending.

 

♠ -
♥ -

♦ A
♣ Q 6

♠ -
♥ -
♦ 10 9
♣ 7

North

 

West         East

 

South

♠ -
♥ -
♦ K (J)
♣ K (10)

 

♠ -
♥ -
♦ Q 5
♣ A

 

East, shown here with four cards, must discard and cannot guard both the ♦K and the ♣K.  At the table East blanked the ♦K, hoping partner had the ♦Q.  WBridge5 guessed correctly, playing the ♦A, ♣A, ♦Q.  If East unguards the ♣K, declarer plays ♣A, ♦A, ♣Q.  WBridge5 won 11 IMPs when Bridge Baron played in 4♠, making 5, at the other table.

General remarks

Overall, the play continues to improve.  The play often appears “expert” as demonstrated by some of these hands, and sometimes appears weak.  This is similar to “less-than” top-level bridge, but a little more frequent.

Shark Bridge, a second-year entry, improved tremendously.  Bridge Baron’s semifinal win over Jack is impressive.  Jack’s results are less than expected, due partially to some bad luck.  Q-Plus Bridge and Micro Bridge are consistent, but appear to fall short of the top competitors, namely WBridge5, Jack and Bridge Baron.  For newcomers RoboBridge and TUT Bridge, this was a learning experience.  Hopefully, they will be back stronger next year.

WBridge5 is impressive.  Its known aggressive style gained much more then it lost.  Besides the clear gains in the finals, where it had no significant losses due to its aggressive bidding, it also gained, much less dramatically, in its earlier matches.  It is clear that WBridge5 is geared for slam bidding, evaluating and reevaluating hands very well, reaching many slams that are based on fit and distribution, not on HCPs alone.

For more information on this year’s championship, past championships, published articles, photos and the robots’ websites, go to www.computerbridge.com or www.ny-bridge.com/allevy/computerbridge