Fuego at the Computer Olympiad in Pamplona 2009: a Tournament Report∗

Martin M¨uller May 28, 2009

Abstract The 14th Computer Olympiad took place in Pamplona, Spain from May 11-18, 2009. The Fuego program won the 9 × 9 Go competition, and took second place in 19 × 19 Go. This report provides some analysis of the games played by Fuego in the competition.

1 Introduction

This was the second Olympiad for Fuego. In its first participation, 2008 in Beijing, Fuego ended up in fourth place in both 9 × 9 and 19 × 19. This year’s competition took place in the beautiful historic Palacio del Contestable in the center of Pamplona. Komi was 7.5 and Chinese rules were used in both tournaments. The Fuego team, software and hardware were as follows: Markus Enzenberger is the creator of Fuego and its lead programmer. Martin M¨uller is team leader, program- mer and opening book author. Broderick Arneson is a programmer. Gerry Tesauro and Richard Segal of IBM Watson Research contributed the distributed memory implemen- tation. The software used was the current svn version of Fuego, with two experimental additions: First, the distributed memory implementation allowed the program to run on a cluster of eight 8-core machines provided by IBM and operated by Rich Segal. Second, for the 19 × 19 competition, an experimental version called FuegoEx was used. This version of Fuego employs knowledge of the classical Go program Explorer for move pruning in core parts of the UCT tree.

2 9 × 9 Tournament

The 9 × 9 competition was played on May 11 - 13. 9 programs took part and played a double round robin. The time limit was 30 minutes per program. Complete tournament results and many gamerecordsare given on http://www.grappa.univ-lille3. fr/icga/tournament.php?id=194. ∗Technical Report TR 09-09, Version 2. May 2009. Dept. of Computing Science. University of Alberta. Canada. All rights reserved.

1 A B C D E F G H J A B C D E F G H J 9 9 9 9 829 25 28 8 8 8 721 4 2 8 6 16 7 723 21 5 7 619 12 3 10 7 5 14 6 619 20 7 6 6 518 13 11 1 26 27 15 35 5 522 4 17 1 9 11 15 27 5 420 30 17 4 418 12 8 10 13 24 4 322 32 9 31 34 3 32 3 16 14 28 3 224 23 33 2 226 25 2 1 1 1 1 A B C D E F G H J A B C D E F G H J

Figure 1: Round 1, Fuego - Yogo.

Round 1: Fuego - Yogo 2:0 Figure 1 shows the games of round 1 against Yogo. Yogo is a strong opponent which took third place in this competition. Last year in Beijing, Fuego and Yogo had split their mini-match with one win each. On the left in Figure 1, Yogo (White) - Fuego (Black). Up to White 4 is a common opening. Previously Black 5 at C7 was in Fuego’s book, but it led to a poor winning percentage. Move 5 at G6 was a new move prepared for this competition, and it worked perfectly in this game. White replied passively and Black got an overwhelmingly strong position. 18 is a desperation move. The white group 18-24 can be killed, but Fuego plays safe with 25 and wins on territory. 35 moves. Black wins by resignation. On the right in Figure 1, Fuego (White) - Yogo (Black). Up to 6 is in Fuego’s opening book. 7 is unexpected, usually Black would connect. White 8 leads to a long tactical sequence. White 12 is a solid move that leads to a very close game. White has a safe half point lead in the end. 28 moves. White wins by resignation.

Round 2: Fuego - Bit 2:0 Figure 2 shows the games against the Chinese program Bit. On the left, Bit (White) - Fuego (Black). 37 moves. Black wins by resignation. On the right, Fuego (White) - Bit (Black). 38 moves. White wins by resignation.

Round 3: Fuego - Fudo Go 2:0 Figure 3 shows the games against Fudo Go. Fudo Go is Hideki Kato’s program. It used to run on a set of Sony playstations, but for this tournament it used more standard A B C D E F G H J A B C D E F G H J 937 9 931 9 836 35 30 27 8 832 30 28 23 8 733 32 8 22 13 11 28 7 735 29 8 18 26 7 629 6 20 9 4 21 6 619 12 9 10 11 24 34 6 524 7 3 1 18 12 5 54 6 1 25 3 5 42 15 31 10 23 34 4 45 14 13 7 33 27 4 314 17 5 19 3 320 21 2 15 36 3 226 25 16 2 222 16 17 37 2 1 1 138 1 A B C D E F G H J A B C D E F G H J

Figure 2: Round 2, Fuego - Bit.

A B C D E F G H J A B C D E F G H J 930 9 951 32 23 56 53 52 69 9 829 24 20 19 17 23 8 850 49 22 19 61 33 68 47 8 725 6 28 4 18 21 31 7 726 16 2 8 3 9 13 46 7 612 27 26 22 32 6 654 18 17 15 7 6 44 12 48 6 59 5 10 1 7 42 41 5 542 25 4 1 27 10 57 58 5 413 11 15 3 43 39 40 4 445 31 43 37 62 63 55 14 59 4 38 45 2 14 37 34 36 44 3 364 40 38 36 5 29 11 20 60 3 248 38 16 33 35 46 2 241 39 35 34 24 28 21 2 150 49 51 52 47 1 166 65 67 30 1 A B C D E F G H J A B C D E F G H J

Figure 3: Round 3, Fuego - Fudo Go. hardware - a cluster of 6 PC. On the left, Fuego (White) - Fudo Go (Black). Up to move 7, the opening seems more promising for White. If White can establish two stable groups, it is often difficult for Black to get enough points to overcomethe large 7.5 komi. For move 8, sliding into the black corner at F2 would be more natural. The wedge at move 10 is very surprising but the result up to 16 is good for White. Move 16 at F2 is a nice, restrained move. 17 is a desperation measure. With 24, White offers the top right in exchange for sure life in the top left. White 36 is an all-out move. Connecting at F3 would be easier to understand but 36 is strongest. 52 moves. White wins by resignation. On the right, Fudo Go (White) - Fuego (Black). Fuego got a difficult game. For move 5, Fuego’s recent book move was D3, but the results were not promising. So before the tournament I changed back to the older move at E3. This makes it a bit harder for White to invade. After White 6, the extension 7 is strongest resistance for Black. Capturing with G6 is safer, but may not be enough for Black. Up to 14 a complex fight starts. Black 15 is bad shape. But it is also a kind of testing move. With 16, Fudo Go decided to give way. Black 19 switches back to the corner. Black’s play is a bit inconsistent here. If Black blocked at H3 instead, a semeai would result. White 24 is a good move, utilizing the double threat of F4. Black 27 seemed weak. If White lives on both sides, it is hard for Black to win. Black 29 surprised me but it is a good try. White cannot ignore it because of H1. The combination of H2 and F3 makes it hard for White to reduce the bottom left. Black 31 closes off one side. After 33, the top left corner is unsettled. White can live with 6 points of territory, while Black can create a seki in sente, or a mannen ko in gote. The main question is how big the black corner in the bottom left will become. I believe that White 34 is the losing move, and if White jumped in at D2 it would win. D2 looks thin but it seems to work. By blocking with 35 Black gets enough points to win. After 54, Black wisely does not try to start the approach move ko. Making seki here is enough. 69 moves. Black wins by resignation.

Round 5: Fuego - FlexGo 2:0 Fuego had a bye in Round 4. Its round 5 opponent was FlexGo. Figure 4 shows the games. On the left of Figure 4, Fuego (White) - FlexGo (Black). The opening is unclear. Move 12 seems doubtful. Defending the other group with F8 or H3 seems preferable. For 13, jumping in at G8 seems more troublesome for White. 14 is an interesting defense. If White lives here the game is won. 32 is a blunder and must be on J6. J4 leaves an approach move ko. The question now becomes whether Black can create enough ko threats. 38, 40 and 42 are very solid. Black resigned without trying the ko. 42 moves. White wins by resignation. On the right of Figure 4, FlexGo (White) - Fuego (Black). Up to 5, the same openingas againstYogo. White 6 is aggressive. White 14 at G4 leads to a difficult fight. Fuego’s evaluation was pessimistic at 47%. White 16 and 18 are a strong combination. Black 27 is a surprising cut. Black’s aim is to take sente and play F3 first. I believe that White 30 should be on E3. With 31, Black gets enough territory. 51 moves. Black wins by resignation. A B C D E F G H J A B C D E F G H J 935 34 33 26 9 950 23 20 21 9 811 29 14 25 31 8 826 19 16 17 48 8 75 10 30 21 7 732 4 2 15 25 29 49 7 67 6 18 16 6 610 3 8 7 5 18 6 542 20 4 1 17 8 15 24 5 511 12 1 6 22 27 30 5 437 19 38 13 22 32 4 413 38 9 14 28 4 341 28 12 2 9 3 23 3 342 39 47 31 34 41 3 239 27 40 2 243 37 36 35 33 2 1 1 146 45 44 1 A B C D E F G H J A B C D E F G H J

Figure 4: Round 5, Fuego - FlexGo. Left: 36 at 33 . Right: 24 at 16 , 40 at 3 , 51 at 20 .

Round 6: Fuego - MoGo 1:1 Figure 5 shows the games against MoGo. Both programs were undefeated after 5 rounds, so this promised to be an exciting match. However, both games were mostly decided by problems with the opening books. On the left of Figure 5, MoGo (White) - Fuego (Black). Black 5 is dubious, after White’s wedge at move 6 Black is in trouble. I looked at various lines after the game, but could not find anything promising for Black. Therefore I changed move 5 to F4, as we will see in the final playoff game. Move 7: the other atari on F7 does not work well, either. Move 9: this move looks crazy, since it allows White to capture the center stone on E5. However, the “solid” move E4 seems to give White an easy win. Up to 27, Black plays for territory. But there are too many weaknesses in Black’s position. 30, 36 and 40 are strong moves. Black desperately tries to complicate the game with throw-ins such as 63. At this point MoGo is running quite short on time. White 68 seems to be a time-trouble move. However, all lines still seem to win for White by at least 0.5 points. Fuego resigns after move 70. On the right of Figure 5, Fuego (White) - MoGo (Black). White 8 is Fuego’s last move in book. White 12 is a tesuji. It makes miai of building a position in the top and bottom left corners. Apparently MoGo was in book up to move 13! The MoGo book is a huge automatically built one. I think it has over 2.3 million entries. However, MoGo’s evaluation on leaving the book was only 47-48%. Arpad Rimmel of the MoGo team was very unhappy with this. When Black kept sacrificing stones in the top right, everyone expected a vicious A B C D E F G H J A B C D E F G H J 967 60 63 64 9 934 36 35 24 9 848 36 55 52 49 42 51 8 829 28 33 18 17 16 8 765 70 17 56 2 50 38 39 66 7 727 26 25 23 14 15 7 637 21 3 14 8 29 40 41 6 619 22 31 4 13 6 545 20 13 12 1 6 5 43 5 512 3 30 1 5 6 5 424 18 15 10 7 4 31 4 420 32 7 8 4 325 23 19 22 11 9 30 59 3 32 9 10 3 247 46 27 26 57 28 32 53 68 2 221 11 2 135 34 44 58 62 61 54 69 1 1 1 A B C D E F G H J A B C D E F G H J

Figure 5: Round 6, Fuego - MoGo. Left: 16 at 1 33 at 4 .

assault on the right side White group. Sure enough, Black attacked with 21 on B2. However, the cut with 22 is hard to deal with. After 26 White was completely safe. 36 moves. White wins by resignation.

Round 7: Fuego - Go Intellect 2:0 Figure 6 shows the games against Go Intellect. On the left of Figure 6, Fuego (White) - Go Intellect (Black). Up to 10, the two white groups look OK. White 16 is strange. G5 would work and capture a big corner. White 18 is a blunder. Black 21 tries to attack, but simply capturing on F5 would give a reasonable game. When White lives easily with both groups, Black’s territory is too small. 44 moves. White wins by resignation. On the right of Figure 6, Go Intellect (White) - Fuego (Black). Fuego is already out of book after move 4. Black 9 is a very interesting attachment. Black gets a strong position. With 16, white should probably live in the bottom right. 19 is a cool, solid answer to the hane. 63 moves. Black wins by resignation.

Round 8: Fuego - Jimmy 2:0 I am unclear about the opponent’s name. The program was registered as Jimmy, which has been a long time participant in computer Go competitions. However, on KGS and in the GTP interface this program appears under the name “coldmilk”. The GTP engine message reads: “coldmilk version 0.13, This program is designed by the student of Jimmy.” Figure 7 shows the games against this program. On theleftof Figure7, Fuego(White) - Jimmy(Black). White 8 looks conservative, but it seems hard for Black to surround enough area. This game looks like a solid win A B C D E F G H J A B C D E F G H J 944 9 963 54 53 52 47 9 88 41 14 20 16 8 828 55 42 43 46 59 8 79 31 4 13 11 32 7 716 4 27 8 45 20 39 38 7 635 5 15 6 12 17 6 614 9 10 19 6 41 6 534 37 1 18 7 42 5 518 15 11 24 1 7 5 35 5 439 3 19 4 421 23 25 36 34 17 4 336 10 22 2 25 33 3 322 51 3 37 31 2 26 32 3 228 27 21 23 24 26 2 257 48 13 12 29 30 2 140 29 30 38 43 1 150 49 56 62 60 40 33 1 A B C D E F G H J A B C D E F G H J

Figure 6: Round 7, Fuego - Go Intellect. Right: 44 at 10 , 58 at 42 , 61 at 55 .

A B C D E F G H J A B C D E F G H J 9 9 936 48 47 46 33 55 54 9 8 8 837 17 28 32 29 10 13 58 53 8 713 7 35 7 715 6 4 7 11 21 52 7 625 37 28 6 627 26 24 38 34 35 20 59 6 527 12 9 31 1 21 17 26 36 5 530 25 5 39 1 40 18 5 432 8 3 20 11 16 29 33 4 431 19 22 9 50 49 4 310 5 2 4 15 14 30 38 3 361 23 2 45 8 3 16 3 26 34 18 19 22 2 244 42 41 57 12 14 2 124 23 1 143 56 60 1 A B C D E F G H J A B C D E F G H J

Figure 7: Round 8, Fuego - Jimmy. Right: 51 at 46 . A B C D E F G H J A B C D E F G H J 9 9 9 9 840 12 25 26 8 829 30 39 8 728 11 8 24 23 16 7 736 10 33 40 7 630 29 2 14 7 6 10 15 41 6 69 4 34 41 6 522 18 27 35 1 9 13 17 5 53 1 17 5 6 5 420 19 3 39 36 4 42 45 4 437 35 27 21 16 7 8 4 321 31 38 37 5 32 47 3 332 26 25 2 15 13 12 11 3 246 33 34 2 231 38 22 18 19 14 23 2 144 43 1 128 20 24 42 1 A B C D E F G H J A B C D E F G H J

Figure 8: Round 9, Fuego - Erica. Right: 43 at 33 .

for White throughout. Maybe Black needs to try another openingat move5 or 7. 38 moves. White wins by resignation. On the right of Figure 7, Jimmy (White) - Fuego (Black). Again, Fuego is out of book after White 4. Black 15 is surprising. White ignores it and Black captures the group with 17, but much aji remains. The game becomes very complex, and Black has several worrisome weaknesses. After 25, it looks like the Black position will hold together. Maybe White can try to wedge at D5 instead of 24. 46 is a blunder. White can get a ko with C9, A5, E9. Even so, if Black eventuallyconnects at F8 the ko seems too indirect for White. 49 is silly but fortunately White answers it. 61 moves. Black wins by resignation.

Round 9: Fuego - Erica 2:0 Figure 8 shows the games against Erica. On the left of Figure 8, Black 7 is the last book move. The result to 17 feels good for Black. 23 and 25 are good endgame. With 31 Black has a sure 1.5 point win. 47 moves. Black wins by resignation. On the right of Figure 8, Fuego (White) - Erica (Black). The opening is difficult. For 11, extending at G3 is an alternative. Black 15 seems soft, since with 18 - 22 White makes a big enough reduction of this corner. Black 15 at F2, White H2, Black F7 would be unclear. 42 moves. White wins by resignation.

Playoff: Fuego - MoGo 2:0 Figure 9 shows the playoff games against MoGo. After 16 games, MoGo and Fuego were tied with 15 wins 1 loss. The playoff rules were as follows: 2 games at first. If A B C D E F G H J A B C D E F G H J 936 54 49 9 940 29 28 27 33 55 9 821 24 15 17 22 35 33 39 8 824 19 23 25 18 21 54 8 723 8 16 14 47 18 34 37 7 716 20 8 2 26 13 39 7 612 9 10 48 40 38 6 634 53 14 3 56 11 12 41 6 513 11 1 5 7 19 45 5 517 15 31 1 57 9 10 5 443 3 53 4 6 44 55 4 435 30 5 4 42 4 358 20 2 26 31 32 41 52 3 332 36 52 51 7 6 3 257 42 30 25 28 27 46 2 238 48 37 22 43 46 2 156 29 1 147 50 49 45 44 1 A B C D E F G H J A B C D E F G H J

Figure 9: Playoff, Fuego - MoGo. Left: 50 at 47 , 51 at 28 .

the score is tied, 2 more games. If the score is still tied, colors are drawn for a deciding fifth game. Both sides made changes to their opening book. MoGo switched to a different machine-built one. I changed the losing line with Black from the first match in Fuego. On the left of Figure 9, Playoff Game 1: Fuego (White) - MoGo (Black). The first game follows a familiar script. White has two groups, and Black must attack. The moves up to 8 follow the book. Actually, Fuego is pessimistic in this opening, but in my judgment White is hard to kill. At move 10 Arpad already said that MoGo would lose. After White 14, both white groups look safe. For 30, connecting at F3 would simplify the game. White can live. Similarly, 52 should be on E4 and 54 on J4. Still, White lives and wins the game. At the end, Black could start a two step ko with B3, A1, D1 but cannot hope to win it. 58 moves. White wins by resignation. On the right of Figure 9, Playoff Game 2, MoGo (White) - Fuego (Black). Move 5 is a new try after the loss in round 6 with G5. After 17, the corner looks big visually but it may not be enough to overcome the komi. I believe that with move 18, White is winning. However, 24 is a simple blunder that throws away the group, the game and the tournament. E8 instead would be a sure win. White goes for complications after this but eventually resigns. 57 moves. Black wins by resignation. 3 19 × 19 Tournament

6 programs played a double round robin. Five rounds were played on May 14, and 5 more rounds with colors reversed on May 16. The time limit was 1 hour per pro- gram for the first 250 moves, and unspecified with a possible referee’s decision af- terwards. These rules will be clarified for next year. Complete tournament results and all gamerecordsare given on http://www.grappa.univ-lille3.fr/icga/ tournament.php?id=193.

Round 1: Fuego (White) - Fudo Go (Black) 1:0 The game is shown in Figure 10. Fuego often plays the one point jump of 12. 16 is an important junction point. 40 would be safer at N2. 43 is good and takes away White’s eye space. White fights very aggressively in Black’s sphere of influence. 51 is a surprising tenuki and seems to give White the upper hand in the fighting. 69 is a tactical mistake, since 70 captures the key stones. White has a clear advantage from this point.

Round 2: Fuego (White) - Zen (Black) 0:1 The game is shown in Figure 11. In the early opening, White goes for territory, but the exchange after move 24 reverses the position, with White getting influence and Black taking profit. 32 lacks substance. Up to 45 again White builds influence but gives Black lots of profit. 60 and 68 are slow. 72 loses points. 88 - 92 is a bad combination. White can connect at S17. 95 is big. 102 is terrible. After the sequence to 113 the game is hopeless for White. In this game, Zen was clearly the stronger program.

Round 3: Fuego (Black) - Go Intellect (White) 1:0 The game is shown in Figure 12. White gets into trouble in the bottom left corner. Up to 77, many white stones die. White cuts with 78 to find a chance, but Black captures the key stones with 89 and has a big lead.

Round 4: Fuego (Black) - GoKnot (White) 1:0 GoKnot is Jacques Basaldua’s program. It plays a beautiful opening, but is still incom- plete, so it has trouble in the later parts of the game. The game is shown in Figure 13.

Round 4: Zen (White) - MoGo (Black) 0:1 This round 4 game against MoGo, shown in Figure 14, is Zen’s only loss in the tourna- ment. The game looks favorable for White, but things start to go wrong in the top left corner and in the center fight. Still, White’s early resignation is surprising. Round 5: Fuego (Black) - MoGo (White) 1:0 The game is shown in Figure 15. The exchange in the top left seems OK for both. As against Zen, Fuego gives up territory in the next fight and builds influence. MoGo invades the bottom with 48 but goes wrong in the continuation. For 50, just extending at K3 would be fine. The resulting fight is good for Black. Both have low number of liberties but Black 67 works well. After 81, another complex fight starts. Just extending at G6 would be simpler. 91 is the first of three failures by Fuego to simply capture at E1. 91 makes the cut of 92 possible. 97 is the second miss. With 103, Black should save the three center stones. White’s capture with 106 is big. 117 ignores E1 yet again. Black gives up a large territory in exchange for an unclear attack. Up to 128, Black isolates some white stones at the bottom but White becomes extremely strong in the top center. At this stage the game seems favorable for White. 135 is bizarre. 137 tries to cut. Up to 150, the stage is set for the decisive fight. White’s chances are better but MoGo is starting to run short on time, while Fuego still has over 30 minutes left. 156 is the first bad move by Mogo in this fight. Attacking from the right or e.g. pushing on H16 seem better. 162 starts a huge ko fight. White wins it but the bottom changes hands with Black’s ko threat on J1. Furthermore, Black retains the option of living in the top right corner. The game is very complex but probably better for black from this point. more complex fighting breaks out in the bottom right center. Black manages to live in sente and switch to the huge attacking move C6. The remaining fights do not change the result of this exciting game. With this win by Fuego, the top three programs Zen, MoGo and Fuego were tied for the lead after the first day, with four wins one loss each.

Round 6: Fuego (Black) - Fudo Go (White) 1:0 The game is shown in Figure 16. The sequencein the bottom left is worrying for Black. White gets a strong position. The cut at 19 seems to be an overplay. For 25, E9 seems to be the only move. But White should not play out the loose ladder. Up to 47, the result is unbelievably good for Black. 61 and 63 should just maintain the ladder on K5. 64 is better on D6. 87 is trying too hard. White 100 is a blunder. White loses either G15 or J16 in a ladder.

Round 7: Fuego (Black) - Zen (White) 0:1 The game is shown in Figure 17. For 37, M2 may be better. For 39, N2 is safe. 47 is bizarre. R5 would be normal. 51 does not work. Black’s loss in this corner is huge. 57 is a move Fuego loves, but its position is too cramped here. 65 should probably cut at F14. 67 is an overplay and should connect on H15. For 81, K18 is very large. White answer to the cut on G6 is odd. Up to 117, Black gets a large territory here. For 123, L12 is natural. 127 should either continue in the lower right, or come back to L12. 135 is very bad. 145 is risky, S15 is a safe move here. 149, 151 and 175 are bizarre. For 153, R11 is safer. The sequence up to 182 is very big and gives White the lead. 193 is a blunder, White could now kill with H19. 194 is also a blunder. Still, getting a seki is enough for White to win. 207 loses more points. The remaining Black moves have no meaning. A tough game but in the end a clear win for Zen. A B C D E F G H J K L M N O P Q R S T

19 19 18 18 17 4 131 84 126128 17 16 6 5 130129123122127 2 16 15 8 14 116121120117 15 14 106105 13 15 119118114115 96 14 13 16 132125113112 97 95 82 13 12 83 124111 98 94 91 92 12 11 3 108107 93 88 87 89 11 10 64 66 86 77 90 10 102 10 9 63 62 59 56 65 79 78 76 81 101 99 100 9 8 61 60 46 47 70 80 73 72 75 12 103109 8 7 11 45 44 31 74 71 68 69 104110 7 6 85 41 9 30 23 27 57 58 67 6 5 1 51 42 40 25 24 26 54 50 55 17 5 4 33 36 29 21 22 53 7 52 4 3 19 28 18 32 20 49 48 3 2 35 34 37 38 43 2 1 39 1

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Figure 10: Round 1, Fuego (White) - Fudo Go (Black) A B C D E F G H J K L M N O P Q R S T

19 229 205 196 19 18 204203198195192189194190188 179224214 216 18 17 219200197 2 191 10 183177234 52 54 50 225 45 238222 70 95 17 16 228213 8 199193 235182 53 138 56 57 239 1 85 86 217 16 15 220218 6 5 169167161 55 137130132 51 58 96 97 87 15 14 202 7 221 166140136134131133 59 123 69 44 68 14 13 210209212 9 171155139135 175 122 42 43 13 12 206223 29 170128215174158153152 36 40 41 12 11 208207 23 20 21 77 240241173157156 34 33 38 31 11 10 211 14 13 46 72 75 76 176149154 32 35 39 10 9 12 15 28 71 73 74 162160141 48 37 30 9 8 27 25 16 17 19 24 159148143142 60 49 81 8 7 125124 26 18 22 78 147146144 61 62 67 66 187 7 6 126 163 168150115145 65 64 186 80 184165 6 5 127118 236 151 90 92 63 82 185 94 101 5 4 4 120119117114110231 89 91 11 93 83 3 99 100105 4 3 164 172116113 84 109230 79 88 243242 98 103 3 2 129178121181111 107106 108227102112 104 2 1 180 237226 1

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Figure 11: Round 2, Fuego (White) - Zen (Black). 47 at 20 , 201 at 2 , 232 at 200, 233 at 204. A B C D E F G H J K L M N O P Q R S T

19 19 18 112 160 97 98 122 18 17 2 114 69 5 109 9 95 91 92 100 4 17 16 90 113 6 108 103 8 99 16 15 68 126 87 88 94 96 107102101115125117121 15 14 84 83 86 163161 105 16 106123104118 14 13 85 79 82 89 111 124129134 13 12 7 77 78 80 127 130140135136 12 11 131 61 76 59 49 81 13 158 141 164 11 10 75 74 60 70 48 47 166154 157 10 10 9 55 57 58 46 45 167155152153 156 9 8 56 42 44 36 38 43 149150151 8 7 72 50 17 40 34 33 37 39 148147159146 12 7 6 71 52 51 41 31 32 162142143132 116 110 6 5 144 53 22 20 23 30 15 133 5 4 139138 21 3 35 14 62 64 65 1 128 4 3 73 25 18 19 27 28 11 119 93 120 3 2 66 54 26 24 137 29 63 67 2 1 1

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Figure 12: Round 3, Go Intellect (White) - Fuego (Black). 145 at 138, 165 at 71 . 167 moves. Black wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 19 18 59 42 60 48 81 69 88 103 18 17 55 56 43 41 47 44 7 52 51 31 68 87 102 17 16 57 58 46 54 45 82 53 18 32 3 16 15 8 61 83 70 35 15 14 67 66 101 14 13 85 79 65 13 12 86 62 71 12 11 148147 25 80 33 11 10 153146 19 14 152 119 10 9 145144 9 149 10 20 134133155 15 118 9 8 93 26 27 150 135131132136120121 8 7 143141 11 151 13 130129128123117139 7 6 142 63 28 126127 40 137138 6 5 140 6 90 125 21 37 4 22 116 5 4 112 64 92 96 89 91 77 75 124 17 16 115122 4 3 84 2 12 94 5 78 154 72 29 24 1 23 104106 3 2 114 98 34 95 74 73 36 39 38 105110 2 1 100 99 97 76 50 30 49 111113107 1

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Figure 13: Round 4, GoKnot (White) - Fuego (Black). 108 at 24 , 109 at 36 . 155 moves. Black wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 109110 94 38 19 18 97 99 95 101 68 93 92 32 11 10 33 34 18 17 103 96 87 98 102 50 55 118 27 29 31 7 115 6 9 8 17 16 106 88 2 54 53 51 119 75 28 30 114111112 1 12 16 15 100 60 56 57 48 117 86 113 13 15 14 104 63 59 52 58 76 116 15 14 14 13 105 67 61 62 70 45 69 24 17 16 13 12 65 64 66 47 46 37 35 26 18 12 11 108107 49 41 36 40 11 10 71 72 77 39 42 5 10 9 80 78 79 83 91 43 9 8 44 73 81 82 90 8 7 89 74 85 84 7 6 6 5 19 23 5 4 4 3 4 3 22 21 20 25 3 2 2 1 1

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Figure 14: Round 4, Zen (White) - MoGo (Black). 119 moves. Black wins by resigna- tion. A B C D E F G H J K L M N O P Q R S T

19 259156251260261 19 18 242222225 235 155 154151157252161159241239249 18 17 224223 21 234153129150165162163253258 240248 17 16 20 4 19 243158152 146147164160 2 16 15 16 15 256257 142145140143 24 15 14 18 5 8 17 148141137134144 44 26 23 30 14 13 12 11 13 124136128138131 42 31 29 28 13 12 14 6 117122135126105133 40 41 46 7 32 12 11 47 111112120121104103 10 39 38 43 36 272238 11 10 221236 113110107106119102100 35 37 45 25 264 10 9 255244237 109108 98 99 123127101167273220 27 201185265 9 8 247246250 125 87 84 95 86 200197166195177 33 22 207206 8 7 212211202 262271 83 80 81 254194267176173172 34 208 7 6 213210199203263270 85 79 78 82 180175174179183184266 6 5 205204 76 90 70 66 67 55 60 196 178181188189190 5 4 245 3 74 65 71 69 50 49 54 268 72 198 1 186 216 4 3 94 92 75 62 59 57 9 48 51 88 61 73 226232187192214218 3 2 96 93 77 64 63 58 56 52 53 89 229228227230193215209217 2 1 97 118 68 116171169 231 233269 1

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Figure 15: Round 5, MoGo (White) - Fuego (Black). 91 at 50 , 114 at 107, 115 at 7 , 130 at 46 , 132 at 38 , 139 at 10 , 149 at 140, 168 at 162, 170 at 165, 182 at 175, 191 at 188, 219 at 41 . 273 moves. Black wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 19 18 86 98 18 17 80 81 93 95 97 3 17 16 4 79 74 83 89 90 94 96 99 16 15 78 73 77 82 88 91 100104105 15 14 47 45 48 84 87 92 101103106108109 14 13 39 36 46 102 107110112113 13 12 37 35 32 38 111114116117 12 11 40 34 33 31 28 6 115118120121 11 10 50 43 30 29 27 20 24 119122124125 10 9 51 23 42 26 21 19 18 71 123126128129 9 8 53 52 69 22 44 16 17 68 25 127 8 7 41 61 62 14 15 70 72 75 7 6 65 64 12 13 54 55 76 6 5 66 67 10 11 58 60 5 5 4 2 63 8 9 59 4 3 49 7 56 57 1 3 2 2 1 1

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Figure 16: Round 6, Fudo Go (White) - Fuego (Black). 85 at 74 . 129 moves. Black wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 192190191197 193195 213234 19 18 209144 88 132131194 135 92 74 80 196 149148151 18 17 143142129127128 55 198 57 91 58 67 75 4 225150138145152 17 16 141140 6 130 61 60 119 69 118230 76 226 2 137146 16 15 246 56 63 59 121 10 112113120 215 147 15 14 139 53 66 64 62 65 71 73 114116 217 54 221 3 14 13 223176 68 186184 78 77 70 72 122115158220218222156 13 12 224 90 175185183 84 79 172174167159160157 166155154178 12 11 216 89 82 83 173 168162 189202179177181182 11 10 228 11 86 81 85 238237 203170219 153180248 10 9 232231 87 171 13 5 136 9 8 244236235 102104 169 29 25 23 21 14 15 134 247 8 7 240239 7 117106 103250 26 27 24 22 19 17 16 12 51 124 7 6 242243 108105107101100 30 28 201187 20 18 47 48 123206 6 5 241 111109110 98 99 207212 34 188 44 164 49 50 126205 5 4 95 8 94 97 32 204 39 37 38 43 46 52 125133 4 3 93 96 9 33 31 208 36 35 40 163 1 233 3 2 249 211 45 41 42 165 245 2 1 161 1

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Figure 17: Round 7, Zen (White) - Fuego (Black). 199 at 113, 200 at 112, 210 at 129, 214 at 145, 227 at 10 , 229 at 113, 251 at 43 , 252 at 40 . 252 moves. White wins by resignation. Round 8: Fuego (White) - Go Intellect (Black) 1:0 The game is shown in Figure 18. 34 should probably be at S15. Up to 41 White becomes extremely thick, but Black takes territory. For 52, atari on P19 is the obvious move. 61 is equivalent to a pass. With 64, defending the right side would be easier to understand. 67 is big, but White tries to go for a huge center. 72 is the wrong atari and must be on R4. 79 is painful for White. Black gets itself into trouble in the top left. Up to 98 White gets a huge profit here. Now White is better. But 154, P5, is too deep. White dies in gote here and lets black make eyes in the top left. This makes the game close again. But then Black ignores the threat of 170, so White wins. From move 205, the huge block of black stones in the middle remains unsettled until 263 accidentally saves them. 267 is suicidal and makes them unsettled again. After 278, Black ran out of time, but it had passed the 250 move mark. Since White has a safe lead of over 10 points even if Black’s block lives, Black’s operator resigned.

Round 9: Fuego (White) - GoKnot (Black) 1:0 The game is shown in Figure 19.

Round 9: MoGo (White) - Zen (Black) 0:1 The game that decided the championship, shown in Figure 20. It was actually played last, after the end of round 10. The game was favorable for MoGo in the middle game, but again MoGo ran short on time, and got outplayed in the fight after move 170.

Round 10: Fuego (White) - MoGo (Black) 1:0 The last game for Fuego is shown in Figure 21. For this game, MoGo switched to the Huygens supercomputer, http://huygens.supercomputer.nl/. MoGo used 20 nodes with 32 cores each, for 640 cores in total. White 10 is wrong, joseki is R4. Up to 27, Black’s profit seems superior to White’s influence. For 38, the only shape is ko at S13. 64 looks like a strong attack but 69 is very good. White gets no compensation for the loss of the bottom left. With 75 and 79 it is Black’s turn to go wrong. 75 on S7 and 79 on S8 were better. Up to 86 the blackstones are cut off. White should answer 105. The fight at the bottom ends with black capturing five stones and White solidifying its position. White 135 and 137 are extremelybig. The game is good for White now. 162 moves. White wins by resignation.

Appendix: Fuego Technical Details

The program version was svn version 869 and 871. The only differences in 871 are some changes to the 9 × 9 opening book. The default settings were used, except for the following. Please see the Fuego documentation for explanations. go_param debug_to_comment 1 go_param auto_save (filename) go_sentinel_file (filename) uct_param_search max_nodes 150000000 uct_param_player reuse_subtree 1 uct_param_player ponder 1 go_rules kgs sg_param time_mode real uct_param_search number_threads 8 uct_param_search lock_free 1 uct_param_search virtual_loss 1 uct_param_search number_playouts 2

The most interesting of those is probably uct_param_search number_playouts 2. It was used only on 9 × 9. The benefit of doing two playouts per leaf is to reduce mem- ory contention, since fewer tree updates are performed. In informal tests before the competition, this was slightly better than the default of one playout. In addition to the standard Fuego settings above, there were more settings for con- trolling the experimental code in FuegoEx and the MPI parallelization.

Revision History

Version 1 Published May 25, 2009 Version 2 Published May 28, 2009. Fixed typos and Figure numbering. Added refer- ences to Figures for 19 × 19 games. A B C D E F G H J K L M N O P Q R S T

19 127219191 120116 107 111 57 19 18 165121 98 93 176115106105102103104117 51 48 41 61 49 18 17 97 94 92 13 89 66 6 101 14 118267 47 40 39 4 22 23 17 16 153151 3 175 90 68 65 112 99 186 56 55 21 50 26 25 19 33 16 15 221128 257 88 87 119113205 53 54 35 34 32 20 28 24 37 15 14 236228 42 258 64 182184185 45 52 43 17 30 29 27 59 139 14 13 227 200199181183114108 46 36 31 18 15 136225 13 12 8 278192187100 95 263218 38 132210 12 11 276275277194193188 96 261217216 266214 268 11 10 12 198197195201202264215245246 16 180213 10 10 9 272206274122 204196 58 262 265244125126171211212 9 8 260259 85 109110 270269241239133242247129157162130166 8 7 271273 11 82 138 62 249222240243123 156155159163252 7 6 135134 86 137 124250251 167253158160161254 6 5 91 143144 140131 235233230177154255 67 81 248 5 4 147142145146148150141189 232231 63 174173179 73 78 84 4 3 1 9 149190152 5 226 7 169 44 164 2 69 72 3 2 209207208223234229224168 83 77 79 70 71 74 2 1 256237238 170172178 76 75 80 1

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Figure 18: Round 8, Fuego (White) - Go Intellect (Black). 60 at 31 , 203 at 102, 220 at 13 . 278 moves. White wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 19 18 62 18 17 4 5 41 36 40 32 17 16 14 20 28 27 64 1 16 15 15 16 17 23 48 47 24 30 46 34 15 14 18 25 42 39 45 14 13 56 21 22 26 43 58 13 12 66 67 68 44 12 11 70 38 8 74 11 10 12 78 50 7 2 73 10 9 52 60 54 77 80 72 10 81 9 8 6 76 75 82 8 7 7 6 9 6 5 19 51 63 49 5 4 3 33 53 37 4 3 31 55 29 61 11 71 35 13 3 2 79 65 69 57 59 2 1 1

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Figure 19: Round 9, Fuego (White) - GoKnot (Black). 82 moves. White wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 271270 218 220 213212210214120 19 18 129107108 82 78 76 77 266224256215211119114105106 18 17 199198 84 79 71 74 75 95 273227257 241117 97 96 17 16 109 2 83 72 73 80 272 21 127110116 1 98 16 15 249248102 85 89 81 86 90 91 240113111100101 15 14 250 39 130132133 88 87 92 93 115104112 99 14 13 251131103134135142 94 196197 148122125126 226 13 12 139 36 136137 153 141121118124 264 12 11 37 33 32 140 42 216200201217149128123144 225 11 10 63 235 34 31 28 30 138 205203202206207151143 38 258259 10 9 65 58 57 234 35 29 26 19 208204191209159158146178 255 9 8 59 53 56 25 274 27 23 22 24 192190193161160 47 48 221 8 7 55 54 50 52 232233231 17 18 238195187239 177 45 46 243 7 6 61 51 49 20 165230 15 16 236194237173186 43 44 246219 6 5 60 64 62 166163 9 164 13 14 229171183172176181 40 155260 5 4 4 167162 7 12 265182169170184 41 222145261 4 3 68 67 11 5 6 8 268179168147174185 3 223242 3 2 70 69 66 10 277180156157175263262 245244254 2 1 154 276188275189 247 1

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Figure 20: Round 9, MoGo (White) - Zen (Black). 150 at 88 , 152 at 72 , 228 at 7 , 252 at 202, 253 at 206, 267 at 260, 269 at 182. 277 moves. Black wins by resignation. A B C D E F G H J K L M N O P Q R S T

19 19 18 68 135 69 90 18 17 60 23 65 21 18 113 31 162 17 16 4 64 66 67 134 91 108136 1 16 15 22 47 41 33 15 14 27 25 40 35 30 37 14 13 26 87 45 43 39 36 38 13 12 24 138 34 32 88 46 44 42 28 12 11 126137140 154153158 86 11 10 124125115120117 155151152157 5 83 82 10 9 48 119101106116118139150149142159 85 78 81 84 9 8 121102 96 95 107 156148147 20 141 79 57 80 8 7 122 97 94 93 89 144143145 19 56 29 76 7 6 123 98 92 99 111109146112 103 50 74 58 59 6 5 52 51 63 49 100 16 105 14 12 10 104 73 72 77 5 4 55 53 2 62 127110114161 3 11 75 4 3 54 61 70 17 15 128 13 7 6 132 9 8 3 2 71 129 131130133 2 1 1

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Figure 21: Round 10, Fuego (White) - MoGo (Black). 160 at 153. 162 moves. White wins by resignation.