Robots visit New York City for 2004 World Computer-Bridge Championship

By Alvin Levy

 

The American Contract Bridge League’s 8th annual World Computer-Bridge Championship was held in New York City from July 13-18, 2004 at the ACBL’s summer North American Bridge Championships.  Eight of the best bridge-playing software programs, or robots, competed for the title of 2004 World Computer-Bridge Champion.

 

History

At the suggestion of New York Times bridge editor Alan Truscott, I petitioned the ACBL in 1996 to hold a computer-bridge event…and thus was born the World Computer-Bridge Championship.

 

The ACBL inaugurated this annual computer-bridge championship in 1997 as a way of encouraging computer-bridge software developers to accelerate their robots’ development to expert class.  Since then progress has accelerated and the top robots have advanced significantly, but not yet to the ranks of expert.  The top robots often exhibit expert play but not consistently enough to be considered expert.

 

This championship has been held every year at an important human international bridge event, with me as the organizer.  The preceding seven championships were held three times at ACBL NABCs, three times at World Bridge Federation (WBF) World Championships and last year at the European Bridge League’s (EBL) first European Open Championship.  When hosting this championship, the ACBL, WBF and EBL have given both financial and organizational support.  For a complete history and details of previous championships go to ny-bridge.com/allevy/computerbridge.

 

Technical remarks

A bridge “table” consists of a central server, or Table Manager (TM), and four connecting computers, which “seat” the robots.  The TM distributes the four hands of each board to the robots.  Play proceeds automatically with the TM receiving and passing information to the robots and recording the play.  This year P4 2.4 GHz/512 MB PCs were used, running under Windows XP.  The speed of play was set at 2 minutes per pair per deal, approximately half that of human play.

 

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

 

Preparation

This is very much a group effort between the organizer, the computer-bridge software developers and the ACBL.  An administrative committee sets the Conditions of Contest with input from the software developers and bridge experts.

 

It is important that the software developers understand their opponent robots’ methods in advance of the competition so that they can prepare defenses.  In human play, advance notice is not necessary when unusual systems are not allowed, as is the case in this competition.  However, in computer-bridge play the robot developers need time to program defenses and store information about the opponent robots’ methods.  Contestants are required to submit a Convention Card (CC) one month before the competition.  This is in the form of a spreadsheet, with over 100 questions.  Once the CCs are published contestants ask each other (through email) even more detailed questions about their methods and conventions.  Since this information is stored in the robots’ memories before the competition begins, few alerts are necessary during play.  In the few instances where alerts are required the pertinent information is input into memory and play continues.

 

Play format

The competition is in the form of team matches, with a team’s robots seated N-S at one table and E-W at the other table.  The boards in a match, or part of a match such as a 16-board set, are played sequentially, first at one table (closed room) and then at the other table.

 

The five-day event starts with a 24-board round-robin with the top four robots advancing to a 64-board knockout (KO) semifinal with carryover.  The round-robin is scored on an international 30-VP scale, where the winning team receives a maximum of 25 VPs for a 52 or more IMP victory.  To earn a carryover in a semifinal or final KO match, a team must both win its head-to-head round-robin match against its KO opponent and finish higher in the overall round-robin standing.  The carryover is the lesser of these two VP differences

 

The Bridge World Editorial on the use of a qualifying round-robin preliminary to a knockout phase

In the August 2004 issue of the Bridge World, Jeff Rubens comments that while a round-robin preliminary segment may provide a substantial amount of guaranteed play for entrants who may have endured considerable expense to play, there are so many flaws that its use may sacrifice tournament quality.

 

Some of the flaws mentioned for human-play are: the scoring system, where the closer it is to win-loss, the greater the danger that small differences will have enormous consequences, and the closer it is to total score, the greater the danger that winning margins of strong teams against weak teams will be relevant; sportsmanlike dumping is a theoretical threat in late matches that will determine who are matched in KO round, or who qualifies for the KO round; and preparation against many different systems is required which severely increases the preparation needed.

 

In computer-play some of these flaws do not exist and others are minimized.  The robots aren’t allowed to dump and their brains can be checked if there is an accusation.  The robots aren’t influenced by the state of affairs so the timing of the matches is irrelevant, except for the suspense of the spectators.  [In fact, this was the case this year.  Viewing Table 2 we see that the stronger robots played each other in early matches therefore greatly reducing spectator suspense at the end.  In the future the highest ranked robots will be matched near the end of the round-robin rather than near the beginning.]  In our competition the preparation needed to study and defend against all the opponents is limited.  This is due, in part, to only allowing systems and conventions that are common international methods so that the software developers can concentrate on improving their robots’ bridge skills and spend less time on understanding and defending against complicated methods.  In our competition Convention Cards are due one month before the competition.  While the list of allowable conventions is large (standard methods vary around the world) the robots’ photographic memories easily digest the methods of their opponents.  For certain classified uncommon treatments the robots explain the meaning to the opponent robots through electronic or manuals means.  We use a 25-VP scale.  It is not close to win-loss and the winning margin against weak teams is softened as the VP award is topped at 25, not 30.  As can be seen in this year’s competition, beating-up on the weaker teams did not affect the round-robin standing.  With one exception, the top five round-robin finishers scored 25 VPs against the weakest three teams.  The one exception was Micro Bridge scoring a 20-10 VP win over the sixth place finisher, Blue Chip Bridge.

 

The competition

The round-robin ended with Bridge Baron topping all competitors with 147 VPs.  Closely behind were Wbridge5, with 145 VPs, Jack, with 138 VPs and Micro Bridge with 131 VPs.  Q-Plus Bridge needed a 20-10 VP win over Q-Plus in their last round match to take the fourth and last semifinal KO spot, but Micro Bridge won 20-10 VPs.


 

The robots, their developers and the final round-robin standing are shown in Table 1.  Table 2 shows the IMP/VP results of each round-robin match and the round that each match was played.

 

Table 1: Entries along with the 24-board round-robin final standing.

Robot

Developers

Country

VPs

Bridge Baron

Stephen Smith, George Yanakiev, Jason Rosenfeld and Tom Throop

USA

147

Wbridge5

Yves Costel

France

145

Jack

Hans Kuijf, Wim Heemskerk and Martin Pattenier

The Netherlands

138

Micro Bridge

Tomio and Yumiko Uchida

Japan

131

Q-Plus Bridge

Hans Leber

Germany

108

Blue Chip Bridge

Ian Trackman and Mike Whittaker

UK

63

Meadowlark Bridge

Rodney Ludwig

USA

37

Sabrina

Pierre Cormault and Gérard Joyez

France

3

 

Table 2.  Round-robin match results

 

Jack

Bridge Baron

Wbridge5

Micro Bridge

Q-Plus Bridge

Blue Chip Bridge

Meadowlark Bridge

Sabrina

Position

VPs

Jack   IMPs

Round

VPs

 

72-15

1

25-5

47-53

2

14-16

27-58

3

9-21

44-45

4

15-15

74-6

5

25-3

152-1

6

25-0

124-8

7

25-0

3

 

138

Bridge Baron

15-72

1

5-25

 

62-36

3

20-10

56-21

4

22-8

81-19

5

25-4

95-35

6

25-4

114-33

7

25-1

121-12

2

25-0

1

 

147

Wbridge5

53-47

2

16-14

36-62

3

10-20

 

60-31

5

20-10

80-30

6

24-6

94-6

7

25-0

102-10

1

25-0

151-5

4

25-0

2

 

145

Micro Bridge

58-27

3

21-9

21-56

4

8-22

31-60

5

10-20

 

77-40

7

22-8

70-44

1

20-10

136-2

2

25-0

141-1

6

25-0

4

 

131

Q-Plus Bridge

45-44

4

15-15

19-81

5

4-25

30-80

6

6-24

40-77

7

8-22

 

101-22

2

25-2

152-18

3

25-0

184-4

1

25-0

5

 

108

Blue Chip Bridge

6-74

5

3-25

35-95

6

4-25

6-94

7

0-25

44-70

1

10-20

22-101

2

2-25

 

55-31

4

19-11

97-32

3

25-3

6

 

63

Meadowlark Bridge

1-152

6

0-25

33-114

7

1-25

10-102

1

0-25

2-136

2

0-25

18-152

3

0-25

31-55

4

11-19

 

112-19

5

25-0

7

 

37

Sabrina

8-124

7

0-25

12-121

2

0-25

5-151

4

0-25

1-141

6

0-25

4-184

1

0-25

32-92

3

3-25

19-112

5

0-25

 

8

 

3

 


 

Q-Plus Bridge did not make the semifinals but it did win the round-robin “best-played hand” award for its play on this deal which occurred in the forth round against Jack.  26 IMPs were at stake.  13 IMPs to Q-Plus Bridge if it makes 6© and 13 IMPs to Jack if it fails.

 

Board 4

Dlr: West

Vul: Both

North

ª 9 8 4 3
© J 9
¨ 10 9 7 6
§ K 6 4

 

 

West

ª A Q

© A 10 5 2

¨ K Q 2

§ A 9 8 7

 

East

ª 7
© K Q 6 4 3
¨ A 8 4
§ 10 5 3 2

 

South

ª K J 10 6 5 2
© 8 7

¨ J 5 3

§ Q J

 

 

 

West

North

East

South

Q-Plus

Jack

Q-Plus

Jack

1§

Pass

1©

1ª

2ª

Pass

4ª

Pass

5§

Pass

6©

All Pass

 

With the 1ª bid by South, West’s hand became bigger, and the Q-Plus Bridge robots bid to an overly aggressive heart slam.  South led a low spade, and declarer finessed, drew trumps, eliminated diamonds and spades, cashed the §A and followed with a low club.  The defense was helpless and Q-Plus Bridge scored +1430.

 

Semifinal

In the semifinals, round-robin first place finisher, Bridge Baron, had a 14 IMP carryover against fourth place finisher, Micro Bridge, and second place finisher, Wbridge5, had a 2 IMP carryover against third place finisher, Jack.

 

The last time Jack played Wbridge5 in a championship KO stage was the 2002 finals.  That final was the closest KO final in computer-bridge history with Jack winning by 1 IMP.  This year Jack continued its winning ways, this time defeating Wbridge5 more comfortably, 157-118.  In the other semifinal match Bridge Baron defeated Micro Bridge 166-126.


 

Board 64 of the semifinals earned Jack 17 of its 39 IMP margin of victory.

 

Board 64               North

Dlr: West              ª 6 5 3

Vul: E-W               © Q 10 4

                            ¨ 10 8 7 2

                            § 10 8 5

West                                        East

ª 8                                          ª A K Q 4 2

© 8 2                                       © K 9 3

¨ A K Q J                               ¨ 6 5

§ K Q J 7 6 3                          § A 4 2

                            South

                            ª J 10 9 7

                            © A J 7 6 5

                            ¨ 9 4 3

                            § 9

 


West

North

East

South

Jack

Wbridge5

Jack

Wbridge5

1§

Pass

1ª

Pass

2¨

Pass

2©

Pass

3§

Pass

4NT

Pass

5ª1

Pass

5NT

Pass

6¨2

Pass

6NT

All Pass

 

1 two key cards and the §Q

2 one king

 

West

North

East

South

Wbridge5

Jack

Wbridge5

Jack

1§

Pass

2ª

Pass

3¨

Pass

3ª

Pass

3NT

All Pass

 

 

 

Jack found the perfect contract, 6NT by East.  Jack took thirteen tricks after the lead of the ªJ, +1470.   5NT asked for kings.  East was planning to bid 6§ if West didn't have the ¨K.  Indeed, if West has ª8 ©Q2 ¨AQJ7 §KQJ763, for example, 6§ is the superior contract.

 

At the other table, Wbridge5 did not reach slam.  The strong 2ª bid crowded the auction and Wbridge5 stopped in 3NT, played from the wrong side.  Jack found the deadly lead of the ©10.  Now the defenders took the first five tricks for down one.  Jack normally leads low from honor-third.  However, after simulating possible layouts, Jack saw the danger of blocking the suit and therefore chose the ©10 lead instead of the ©4.  The unexpected extra bonus was the ©10 lead won the first trick and hearts could be continued through the king.


 

In the other semifinal semifinal match, both teams arrived at 6§ and could have been beaten on a heart lead.

 

West

North

East

South

Bridge Baron

Micro Bridge

Bridge Baron

Micro Bridge

1§

Pass

1ª

Pass

3§

Pass

4NT

Pass

5ª

Pass

6§

All Pass

 

West

North

East

South

Micro Bridge

Bridge Baron

Micro Bridge

Bridge Baron

1§

Pass

2ª

Pass

3¨

Pass

3NT

Pass

4§

Pass

4ª

Pass

4NT

Pass

5©

Pass

6§

All Pass

 

 

 

At one table Micro Bridge was on a guess between a diamond and a heart lead, and chose a diamond.  At the other table, if Bridge Baron doubles 5©, East will likely play in 6NT.  Without the double North led a diamond.  6§ making 7 at both tables for a wash.

 

Semifinals

Carryover

1-16

17-32

33-48

49-64

Total

Bridge Baron, USA

14

48

38

43

23

166

Micro Bridge, Japan

0

49

33

19

25

126

 

 

 

 

 

 

 

Wbridge5, France

2

19

42

20

35

118

Jack, The Netherlands

0

58

21

26

52

157

 

For the second year in a row Jack and Bridge Baron were playing for the championship.  There was no carryover as Jack defeated Bridge Baron in their head-to-head round-robin match and Bridge Baron finished higher in the round-robin standing.

 

Jack defeated Bridge Baron, 157-97, to claim the championship for the fourth year in a row.

 

Final

Carryover

1-16

17-32

33-48

49-64

Total

Bridge Baron, USA

0

16

39

13

29

97

Jack, The Netherlands

0

40

22

40

55

157


 

To show the level of play of these two robots, the second quarter of the finals is presented.  This 16-board set was the only set that Bridge Baron bested Jack.

 

Board 1            North

Dlr: North         ª 5 4 2

Vul: None         © 10 4

¨ 10 7 3

§ A K 7 6 4

West                                        East

ª K J 6                                    ª A Q 8 3

© A K Q 9 7                             © 5 2

¨ J 5 2                                     ¨ A Q 9 8 6

§ Q 9                                       § J 5

South

ª 10 9 7

© J 8 6 3

¨ K 4

§ 10 8 3 2

 

West    North    East      South

BB        Jack     BB        Jack

            Pass     1¨        Pass

1©        Pass     1ª        Pass

3NT     All Pass

 

West    North    East      South

Jack     BB        Jack     BB

            Pass     1¨        Pass

1©        Pass     1ª        Pass

2§1      Pass     2¨2      Pass

4ª        All Pass

 

1 asking

2 No club stopper and less than 3 hearts; does not promise 5 diamonds

 

Jack reached the best contract, 4ª on a 4-3 fit, and made six when Bridge Baron led a heart and didn’t return a club after winning the ¨K.  Jack reasonably placed the final contracted at 4ª.  Bridge Baron lucked out when the opening leader made the normal low club lead from AKxxx.  2 IMPs to Jack.


 

Board 2            North

Dlr: East           ª Q J 10 8 3

Vul: N-S           © 8 7

¨ Q 9 2

§ K J 10

West                                        East

ª A 9 2                                    ª K 2

© A Q 6 5 3                              © 10 4 2

¨ 8 5                                        ¨ A K 6 3

§ 5 4 3                                     § A 9 8 7

South

ª 7 5 4

© K J 9

¨ J 10 7 4

§ Q 6 2

 

West    North    East      South

BB        Jack     BB        Jack

                        1¨        Pass

1©        1ª        Dbl1      2ª

4©        All Pass

 

West    North    East      South

Jack     BB        Jack     BB

            1§       Pass

1©        1ª        Dbl1      2ª

4©        All Pass

 

1 support double

 

The ªQ was led at both tables.  Jack cashed the ©A before ruffing a spade and led a heart toward the ©K.  Bridge Baron took the heart finesse.  +420 at both tables.

 


Board 3            North

Dlr: South         ª A 8 7 5 4 3 2

Vul: E-W          © A Q 10 7

¨ J 7

§ -

West                                        East

ª J 9                                        ª Q 6

© 5 4 3                                     © K 9 6 2

¨ K 10 5                                  ¨ A Q 6

§ K J 10 9 7                             § A Q 6 3

South

ª K 10

© J 8

¨ 9 8 4 3 2

§ 8 5 4 2

 

West    North    East      South

BB        Jack     BB        Jack

Pass

Pass     1ª        Dbl       Pass

2§       2ª        4§       Pass

4NT     Pass     5ª        Pass

6§       Dbl       All Pass

 

West    North    East      South

Jack     BB        Jack     BB

Pass

Pass     1ª        Dbl       Pass

3§       4ª        All Pass

 

At one table Bridge Baron had an accident.  It appeared that robots don’t always play as if they are clones of each other.  4§ should suggest a stronger hand and West took his partner to have a stronger hand and reached 6§x, -800.  At the other table Bridge Baron took a reasonable shot at 4ª, +420 and 9 IMPs to Jack.


 

Boar 4              North

Dlr: West          ª A 7 6 5 2

Vul: All             © 5 4

¨ A J 7 3

§ A J

West                                        East

ª Q 10 8 4                                ª K 9

© Q 8                                       © A J 10 9 3 2

¨ 9 6                                        ¨ 10 8

§ K Q 9 5 3                             § 10 8 2

South

ª J 3

© K 7 6

¨ K Q 5 4 2

§ 7 6 4

 

West    North    East      South

BB        Jack     BB        Jack

Jack     BB        Jack     BB

Pass     1ª        3©        All Pass

 

Both Easts viewed a 3© preempt as best.  Humans would not have the stomach to bid 3© with this vulnerability.  With five losers -100 was the result at both tables.

 

Board 5            North

Dlr: North         ª 9 2

Vul: N-S           © A J 10 9 6

¨ K 6

§ J 9 8 3

West                                        East

ª K J 3                                    ª Q 6

© K Q 7 4                                © 8 5 3

¨ A J 10 5                                ¨ Q 7 4 2

§ 7 5                                        § A K 10 4

South

ª A 10 8 7 5 4

© 2

¨ 9 8 3

§ Q 6 2

 

At both tables South opened 2ª and after three passes the West led the ©K.  Declarer won the ©A, ruffed a heart and led a diamond to the ¨K and returned a diamond.  +110 at both tables.


 

Board 6            North

Dlr: East           ª 6 2

Vul: E-W          © K J 10 9 7 6

¨ Q 9 8

§ 10 4

West                                        East

ª K J 5                                    ª A 10 4

© -                                           © A Q 8 5 2

¨ A K J 10 2                            ¨ 4 3

§ K Q 9 6 3                             § A 7 5

South

ª Q 9 8 7 3

© 4 3

¨ 7 6 5

§ J 8 2

 

West    North    East      South

BB        Jack     BB        Jack

Jack     BB        Jack     BB

                        1©        Pass

2¨        Pass     2NT     Pass

3§       Pass     3NT     All Pass

 

Both sides missed the good 6§ contract when both Wests took a conservative view and passed 3NT.  If East held ªAQx ©KQJxx ¨xx §xxx, then 4NT over 4§ would still have been safe.

 

Board 7            North

Dlr: South         ª 10 8 5 4

Vul: All             © 2

¨ 10 9 8 3

§ Q 9 4 2

West                                        East

ª 6 2                                        ª A K J 9 3

© Q 9 7                                    © J 8 6 4

¨ K Q J 7                                 ¨ 4 2

§ 10 7 5 3                                § K 8

South

ª Q 7

© A K 10 7 5

¨ A 6 5

§ A J 6

 

West    North    East      South

BB        Jack     BB        Jack

                                    1©

Pass     Pass     1ª        2©

All Pass

 

West    North    East      South

Jack     BB        Jack     BB

1©

Pass     Pass     1ª        All Pass

 

At one table Jack made a bad 2© bid.  After ªA, ªK, ªJ ruffed and overruffed, West returned the ¨K.  Declarer won the ace and played ©A and ©K pitching a diamond.  After §A, §J East won the §K and returned a diamond.  West’s fourth diamond forced declarer to ruff and South was end played at trick 12, -300.  Declarer could have saved one trick by either ducking the first diamond or not pitching a diamond on the second heart.  At the other table Bridge Baron should Dbl over 1ª and reach 2§ or push N-S higher. Defending 1ª, Bridge Baron took seven tricks with two hearts, two heart ruffs, two clubs and one diamond, +100.  9 IMPs to Bridge Baron.

 

Board 8            North

Dlr: West          ª A 10 8 7 5 3

Vul: None         © -

¨ K 10 7

§ 8 7 3 2

West                                        East

ª K J 2                                    ª Q 6

© K J 8 4                                  © A 10 6 3

¨ Q J 3                                    ¨ A 9 8 5 4 2

§ K J 6                                    § Q

South

ª 9 4

© Q 9 7 5 2

¨ 6

§ A 10 9 5 4

 

West    North    East      South

BB        Jack     BB        Jack

Jack     BB        Jack     BB

1NT     Pass     2§       Pass

2©        2ª        4©        All Pass

 

Both declarers guessed to play the ©A first but still had to lose one trick in each suit for down one.  It is too difficult to reach the best contract, 3NT.


 

Board 9            North

Dlr: North         ª A Q 10 7

Vul: E-W          © 9 3

¨ Q 8

§ J 5 4 3 2

West                                        East

ª 8 5                                        ª 9 6 4 3

© J10 8 6 2                               © 7 5 4

¨ J 10 9                                    ¨ 7 6 3

§ A Q 9                                   § 10 7 6

South

ª K J 2

© A K Q

¨ A K 5 4 2

§ K 8

 

West    North    East      South

BB        Jack     BB        Jack

            Pass     Pass     2§

Pass     2¨        Pass     2NT

Pass     3§       Pass     3NT

Pass     4§!      Pass     4©!

Pass     4NT     Pass     5©

Pass     5ª        Pass     5NT

Pass     6NT     All Pass

 

West    North    East      South

Jack     BB        Jack     BB

Pass     Pass     2§

Pass     2NT     Pass     3NT

All Pass

 

Jack could not avoid 6NT with South promising 23-24 hcps and North holding 9 hcps plus a five-card suit.  4§ was forward going with at least five clubs and 4© showed less than 3 clubs (4¨ would show 3+ clubs).  While 6NT turns out to be a 32% slam it was a good bet before the actual hands were revealed.  Bridge Baron stopping conservatively at 3NT.  11 “slightly lucky” IMPs to Jack, but it would have been 11 “slightly lucky” IMPs to Bridge Baron if diamonds weren’t 3-3.


 

Board 10           North

Dlr: East           ª 10 9 6 2

Vul: All             © 4 2

¨ A Q 6 5 4

§ J 3

West                                        East

ª K Q                                      ª A J 8 7 4

© K Q 8 7 6                              © 10 9 5 3

¨ J 10 8                                    ¨ 3

§ A 10 4                                  § K 9 7

South

ª 5 3

© A J

¨ K 9 7 2

§ Q 8 6 5 2

 

West    North    East      South

BB        Jack     BB        Jack

                        Pass     Pass

1NT     Pass     2§       Pass

2©        Pass     4©        All Pass

 

West    North    East      South

Jack     BB        Jack     BB

                        Pass     Pass

1NT     Pass     2§       Pass

3§1      Pass     3¨2      Pass

3©        Pass     4©        All Pass

1 a minimum with at least 5 hearts

2 transfer forcing a 3© bid

 

At one table Bridge Baron made 12 tricks for +680 on the §J lead and a club return after South won the ©A.  At the other table Jack led a spade and South returned a diamond after winning the ©A, +650.  1 IMP to Bridge Baron.


 

Board 11           North

Dlr: South         ª Q 10 7 6

Vul: None         © K 4

¨ J 6

§ K 8 4 3

West                                        East

ª J 8 2                                     ª A 4 3

© Q 8 6                                    © A J 10 9 7 3 2

¨ 10 3                                      ¨ K 9

§ A Q 10 9 2                            § J

South

ª K 9 5

© 5

¨ A Q 8 7 5 4 2

§ 7 5

 

West    North    East      South

BB        Jack     BB        Jack

Jack     BB        Jack     BB

                                    3¨

Pass     Pass     4©        All Pass

 

At both tables the bidding and play were identical.  The opening ª5 lead went to the ª10 and ªA.  Both declarers led a club to the §A and passed the ©6.  Next the §Q was led and both Norths defended best by not covering.  Declarers discarded a spade and continued with the §10 covered and ruffed; cashed the ©A; crossed to the ©Q and cashed the §9; making 11 tricks (seven hearts, three clubs and a spade) at both tables for +450 and a wash.


 

Board 12           North

Dlr: West          ª A J 9 7 2

Vul: N-S           © K 10 7 2

¨ 9

§ 8 6 4

West                                        East

ª 8                                           ª K Q 6

© A Q 5 4 3                              © J 9 8

¨ A K Q 10 6                           ¨ 7 4 3

§ 3 2                                        § A K 10 7

South

ª 10 5 4 3

© 6

¨ J 8 5 2

§ Q J 9 5

 

West    North    East      South

BB        Jack     BB        Jack

1©        1ª        2ª        3ª

4©        All Pass

 

West    North    East      South

Jack     BB        Jack     BB

1©        Pass     2§       Pass

3¨        Pass     3©        Pass

4©        All Pass

 

Both declarers made 10 tricks, losing a spade and two hearts.  At one table Jack led a diamond.  Bridge Baron took the heart finesse and then a heart to the Jack, losing two hearts and a spade.  At the other table Bridge Baron led the ªA.  Jack played the ©A and a heart to the Jack, losing two hearts and a spade.


 

Board 13           North

Dlr: North         ª A J 4 3

Vul: All             © A J 4

¨ 6 4

§ K J 9 8

West                                        East

ª Q 9 8 7                                 ª K 10 2

© 10 7 2                                   © K 9 8

¨ Q 3 2                                    ¨ K 10 8 7

§ A 7 2                                    § Q 5 3

South

ª 6 5

© Q 6 5 3

¨ A J 9 5

§ 10 6 4

 

West    North    East      South

BB        Jack     BB        Jack

Jack     BB        Jack     BB

            1§       Pass     1©

Pass     1ª        Pass     1NT

Pass     2©        All Pass

 

Both declarers went down two tricks, -200.  When Jack declared 2© Bridge Baron led the fourth best spade and declarer played the ªJ? to East’s ªK.  After a spade return to North’s ªA, a low diamond went to South’s ¨9! and West’s ¨Q.  Now the defense did well by returning a trump and a trump continuation when East won the ©K.  Declarer won in dummy and led a diamond ¨A? and ruffed a diamond, ruffed a spade, played the last trump and then miss-guessed clubs and took no more tricks.  At the other table Jack led a diamond to the ¨K and ¨A and declarer erred by playing trumps.  East won the ©K and returned a trump. Now declarer played a diamond to the ¨J? and ¨Q.  A spade went to dummies ªJ and East’s ªK.  East led a trump won by the ©Q.  When declarer miss-guessed clubs East returned a spade removing one of North’s entries to the long club and West did well to duck a club, thus removing the second entry to the long club.  Declarer eventually lost two more diamonds.


 

Board 14           North

Dlr: East           ª A Q

Vul: None         © K Q

¨ K Q 5 3

§ Q J 5 3

West                                        East

ª J 8 7 6 3                                ª K 9 2

© 10 9 8 6 5                              © A J 4 2

¨ 8                                           ¨ A 9 7 2

§ 9 3                                        § 4 2

South

ª 10 5 4

© 7 3

¨ J 10 6 4

§ A K 10 5

 

West    North    East      South

BB        Jack     BB        Jack

                        1¨        Pass

Pass     Dbl       Pass     1NT

Pass     3NT     All Pass

 

Opening lead: ª6

 

West    North    East      South

Jack     BB        Jack     BB

                        1¨        Pass

Pass     2§       Pass     Pass

Dbl!      2NT     Pass     3§

Pass     3NT     All Pass

 

Opening lead: ©4

 

At one table Bridge Baron (West) led a spade and declarer had no chance.  The defense took four spades and two aces, -100.

 

At the other table the auction was strange indeed.  Bridge Baron miss-described its hand when it bid 2§ rather than Dbl in the balancing seat.  Jack (East) led a low heart and West played the ©5 and declarer won the ©Q.  East captured declarer lead of the ¨Q with the ¨A and led back a spade, +460.  Based on the play at trick one East knew West held © 10 9 8 6 5 but rather than settle for down one East returned a spade knowing from the bidding that North could not have nine tricks...not a good idea.  Computers act differently than humans.  Humans would have cashed the four heart tricks first and then attacked spades.  11 IMPs to Bridge Baron.


 

Board 15           North

Dlr: South         ª A 3

Vul: N-S           © 7 5

¨ A K J 10 7 5 4

§ 6 2

West                                        East

ª J 9 4                                     ª Q 10 8 6 5

© Q J 10                                   © K 8 4 2

¨ 6 2                                        ¨ Q 9 8

§ A K 9 8 4                             § 3

South

ª K 7 2

© A 9 6 3

¨ 3

§ Q J 10 7 5

 

West    North    East      South

BB        Jack     BB        Jack

                                    Pass

Pass     1¨        Pass     1©

Pass     3¨        Pass     3NT

All Pass

 

Opening lead: §A

 

West    North    East      South

Jack     BB        Jack     BB

                                    Pass

1§       1¨        1ª        1NT

Dbl1      2¨        2ª        Pass

Pass     3NT     Dbl       All Pass

1 support double

 

Opening lead: ª9

 

At one table Bridge Baron made a good decision to lead the §K.  With a low club lead declarer has an easy 10 tricks.  West continued with the §A? and then led the ©Q.  Cashing the §A was a mistake but Bridge Baron recover nicely.  Declarer ducked the ©Q and won the ©J return, then cashed the club winners squeezing East.  East discarded four spades.  Declarer cashed the ªA and ªK.  If East discards a low heart it will be endplayed, but East found the ©K discard and declarer had to go down one, -100.

 

At the other table Bridge Baron’s bidding appears adventurous, but a simulation after the 2ª bid produced a greatly different result then the simulation before the 2ª bid.  However, for a more cooperative auction, 3¨ at North’s second turn was best.  2¨ followed by 3NT eliminated South from the auction.  If 3NT was right Bridge Baron could have ended in 2¨, and if 3¨ was right Bridge Baron could not get there.  After the spade opening lead declarer took nine tricks, +750 and 13 IMPs to Bridge Baron.


 

Board 16           North

Dlr: West          ª Q 9 8 7 5 3

Vul: E-W          © J 4

¨ Q 5

§ 6 3 2

West                                        East

ª 10                                         ª A J 6 4

© K 9                                       © Q 8 7 5 2

¨ 10 9 8 4 2                              ¨ J

§ A 10 8 7 4                             § Q 9 5

South

ª K 2

© A 10 6 3

¨ A K 7 6 3

§ K J

 

West    North    East      South

BB        Jack     BB        Jack

Pass     Pass     1©        Dbl

Pass     1ª        Pass     2¨

Pass     2ª        Pass     2NT

Dbl       All Pass

 

Opening lead: ©K

 

West    North    East      South

Jack     BB        Jack     BB

Pass     Pass     Pass     1¨

Pass     2ª        All Pass

 

Opening lead: §5

 

Even after the ©K lead, declarer only had 7 tricks, -100.  In 2ª declarer won the second club and tried to discard a heart on the third diamond.  The defense ended with two diamond ruffs, the ªA, §A and one heart, +110 and 5 IMPs to Bridge Baron.

 

Skill and Luck

This set of sixteen boards shows that many IMPs can be gained on both skill and luck.  The luck includes inferior but lucky contacts, bad bids that work out well and good bids that work out poorly, vulnerability, and timing of scores.  Of course the luck balances out in a long match.  While 16 boards are not enough to rule out luck playing a significant role, 64 boards greatly reduce the luck factor.

 

Board 1 saw Jack bid well to avoid 3NT.  However, luck was with Bridge Baron.  Bridge Baron reached the bad 3NT contract and made when the opening leader made the normal forth best lead from AKxxx.  Jack did well to reach the excellent 4ª contract and was unlucky not to have gained 9 more IMPs.

 

On Board 3 Bridge Baron had an accident at one table and made a good decision at the other table.  The accident cost 9 IMPs, while the good decision, to bid game, came at an unlucky time.  It reduced the total score from 630 (if BB played in 3ª) to 380, and gaining only 3 IMPs.  [As can be seen from this board and boards 14 and 15, Bridge Baron often takes unilateral shots at game with great success.]

 

Board 7 saw Jack pay for a bad bid and Bridge Baron get away with a “less bad” bid.  The vulnerability made a difference also.  Had both sides been non-vulnerable, the margin would have been only 5 IMPs rather then 9 IMPs.

 

Board 9 saw Jack gain 11 IMPs when diamonds divided 3-3 (31.75%).  If not 3-3 Bridge Baron would have gained 11 IMPs.  Gaining 11 IMPs was a technical “lucky” gain for Jack.  However, without a relay system, reaching 6NT was normal and unlucky to be only a 32% slam.  So while a technical “lucky” 11 IMP gain for Jack, if diamonds weren’t 3-3 it would have been a practical “unlucky” 11 IMP loss for Jack.

 

Board 14 saw Jack give away 11 IMPs on defense.  This was caused, in part, by Jack’s interpretation of Bridge Baron’s hand based on the bidding and, in part, by the way computers play, namely, if there are two ways to get to the same ending it doesn’t matter which way you take.

 

Board 15 saw Bridge Baron defend 3NT well enough to gain 13 IMPs.

 

Board 16 saw Bridge Baron make a good decision to gain 5 IMPs.

 

In this set of boards, both sides were rewarded for good play with the “lucky” IMPs gains and lost by both sides.

 

General remarks

After 296 boards Jack demonstrated the most consistent good play and the title of computer-bridge world champion is well deserved.  Bridge Baron, Wbridge5, Micro Bridge and Q-Plus Bridge also demonstrated fine play.

 

The level of play of the top robots has greatly improved over the past seven years, with the top programs such as Jack, Bridge Baron, Wbridge5, Micro Bridge, Q-Plus Bridge and GIB (not entered in this championship for the past two years) making great progress.  Before this championship began in 1997 the best robots were barely approaching Intermediate play.  Now the best robots would be hard to beat in club play and a pair of Jack-Jack robots would be stars.  This has been demonstrated recently in matches pitting expert human players against a team of Jack robots (Australian Bridge, Vol. 34, No. 5, October 2003, p.4 and International Computer Games Association Journal, Vol. 27, No 1, March 2004, p. 52).

 

For more information on the World Computer-Bridge Championship, including its history, past championship results, articles and photos, go to computerbridge.com or ny-bridge.com/allevy/computerbridge