2009 World Computer Championship

For a list of other events, see Event Reports

The entrants

This year is the first time the number of candidates have hit the limit of eight imposed by the tournament rules. If more than eight developers had entered bots, there would have been a preliminary screening based on ratings. However this year, seven developers entered bots, and one extra from previous tournaments (Zombie2008CC) was added by Omar to fill the schedule. Two of the seven are new entrants into the championship arena, Badger and Rat, both by developers with Arimaa bot experience who have started afresh this year. The symbolism behind their animal monikers suggests that they will also take rather different approaches to one another. GnoBot re-enters the scene, having previously participated until 2007, and after having a full overhaul of its evaluation function. In addition to these newcomers, the full schedule of 2008 bots have returned, with the exception of last placed Loc. Two of these five (clueless and OpFor) have been under active development throughout the year, and are strong contenders again this year. Special mention must go to Bomb2005CC, the reigning champion of all previous Computer Championships. Its development has been frozen since 2005, and each year its challengers have edged a little closer. Can it hold on once again amongst such a big field, in a year where some of its competitors are for the first time taking advantage of quad core processors? There are signs that this year could spell its downfall, with four of its contenders having won multiple games against it in training.

Bomb2005CC (David Fotland)

The much studied reigning champion remains identical to the incarnation that has won three Championships in a row. Each year it gets a small performance gain due to increased processor speed (2.3 GHz in 2009 vs 2.13 GHz in 2008). Humans have developed numerous strategies to systematically defeat Bomb, but their implementation into computer algorithms has not been successful so far.

Sharp2008CC (David Wu)

Last year's runner up returns this year. While there was further development on Sharp during the year unfortunately the new version wasn't ready in time for the tournament. Sharp's major weapons are complete static goal and trap detection, which make it a tactical behemoth, and are unmatched in any other bot.

clueless (Jeff Bacher)

Clueless has made huge strides this year, and has occasionally taken the scalps of some of the top human players. It is parallel-enabled, so will have a significant speed advantage over many of its competitors. In gameroom testing, it has had wins against all other contenders, so is certainly a chance at the title.

OpFor (Brian Haskin)

Last year's third place winner has returned bigger and better than ever. In 2008 it was new on the scene, and some of its greatest weaknesses have been eliminated since then. It now includes complete 4 step goal and trap detection. In gameroom testing, it has had wins against all other contenders, so is certainly a chance at the title.

Zombie2008CC (Evan Dorn)

Unchanged since 2008, Zombie was added to complete the schedule of 8 bots.

GnoBot (Toby Hudson)

One unusual feature of GnoBot is an opening book that allows it to follow lines that have previously won against an opponent. If the opponent replies in the same way to the same situations, this means that GnoBot can win an entire game against even the best bot without thinking. Usually that is not the case, as differing processor speeds or non-determinism bring about deviations in the play which rapidly diverge from previously seen situations. However occasionally play does continue along a line for long enough that GnoBot gains a significant advantage even before it is out of the book (for example an elephant blockade). Will this feature come into play against those bots that have remained static over the last year?

Another unusual feature is the top-down evaluation function, an attempt to take a more strategic and holistic view of the board position.

Along with Clueless and Badger, GnoBot is the other bot that is parallel-enabled, which gives it a significant speed advantage over many of its competitors. In gameroom testing, it has had wins against all other contenders, so is certainly a chance at the title.

Badger (Paul Pogonyshev)

Paul Pogonyshev was previously involved in the development of Aamira, renowned for its vigorous attacking play. His new contribution, Badger is a very recent creation, and has been rocketing up the ladder as features have been added. Along with Clueless and GnoBot, it is now parallel enabled, giving it an advantage over those competitors that are not. Its Championship entry fees were sponsored by Karl Juhnke, in return for its winnings. Will the rapid development all be too late? Will it recoup the entry fee with a win or two? Or will it rocket right into contention? This is perhaps the darkest horse in the championship.

Rat (Gerhard Trippen)

The least conventional of this year's entries is Rat. It takes a highly selective approach to examining the game tree, and chooses moves primarily on the value of the moves themselves, rather than evaluating the resulting board position. Although low-rated, Rat could play an important cameo role in this Championship because it has been developed specifically with the objective of beating Bomb in mind. It attempts to prosecute anti-Bomb strategies developed by bot bashers over the years (in particular a strategy principally expounded by Patrick Dudek). In gameroom tests, this has been extremely effective, with wins against all versions of Bomb. However its general play is of lower quality. So, the biggest question for Rat is whether it will get the opportunity to show its wares with a pairing against Bomb, or will it be knocked out too early for them to meet?

Current move categories are goals, captures, retreats, kidnappings, attacks, and some trap protections. So there should be many more to come. The search is guided to some extend by certain patterns in the position. Rat is capable of recursion and should be able to see an opponent's goal in one and she can see if she is going to lose a piece. (at July 30th 2008)

Pre-Tournament Analysis

Without hyperbole, the 2009 World Computer Championship promises to be the most exciting ever. There are two additional participants versus last year and there is greater uncertainty than ever about how the tournament will unfold. Bomb, with 5 consecutive titles under its belt and a 28-3 tournament record, enters as the #4 seed and is considered a dark horse in this 2009 tournament. Clueless, GnoBot and OpFor have made great advances during the past 12 months and all have a very realistic chance to dethrone Bomb for the first time ever. Badger, Zombie, Rat and Sharp are capable of pulling off an upset here or there, but the general feeling amongst the experts is that they are all long-shots to win the title.

Round 1

bot_GnoBot vs. bot_Rat

With GnoBot able to use its opening book to copy past wins against an opponent the first 11 moves it made were from its book. The game it followed was Game 98686. At the time that Rat deviated on move 11s it had started an EH attack on the c3 trap while GnoBot was trying to pull a piece out with its lone Elephant. At move 13 Rat pushed a Cat back to e6 but also left its own cat hanging on g6. This led to both sides capturing a dog and cat by move 20. With GnoBot threatening to capture Rat's camel next and Rat not having an immediate threat, Rat was forced to retreat its elephant back to e6. GnoBot was then able to capture a horse at c3 and was threatening a dog when Rat timed out on move 23s.

bot_Sharp2008CC vs. bot_clueless

This is actually the second game between these two bots. The result of the first game was annulled due to server problems.

Sharp opened the game with its patented camel charge. By move 7, clueless had sharp's camel hostage. On move 8, sharp moved its elephant behind the trap, to try and release the camel hostage. After a horse for cat exchange, clueless used all of its pieces to maintain a blockade on sharp's elephant. The game entered a long phase of piece shuffling, resulting in all of the pieces ending up on the right side of the board. On move 30 the action finally got started. Clueless framed a dog on the f3 trap. This allowed sharp's elephant to escape from the blockade. The next 5 moves saw a massive exchange of pieces. After the trades, it was 6 pieces vs 3 pieces. Although clueless gave the spectators some nervous moments, it converted the win.

bot_OpFor vs. bot_Zombie2008CC

OpFor vs. Zombie after 20s dd4w ed3w ec3s Rb3e Rc3x

The game opened in an unusual way as OpFor used its entire 3rd move to transfer its camel to the east side, while the gold horse stood on its original b2 square. Zombie advanced its own horse to b3 on 4s, the beginning of a long chain of action-packed moves in the south. The gold elephant took the silver horse hostage on move 6 and Zombie responded with a rabbit advance to b4. If Zombie was intending to swarm the de-centralized gold elephant, it never had time to continue with that plan because OpFor immediately attacked with its camel in the northeast, creating a second silver horse hostage in the east, but leaving its cat exposed on f2 with 8g. Zombie captured the cat, simultaneously protecting its eastern horse hostage and allowing OpFor the option of a horse exchange. OpFor, however, opted to defend its f3 trap on 9g, leaving the silver elephant awkwardly placed at f2 with the two silver horse hostages still very much in danger. Zombie didn’t have enough time to place its camel on f4 and elephant on d3, so it had to use a rabbit and dog to temporarily protect the c3 trap. The silver defenders were quickly broken up and the rabbit was drained into c3 on move 12g. The silver elephant finally returned to its natural d3 square on 13s, trusting in the silver camel to defend the southeast trap from f4. The gold elephant left the horse hostage to pursue the silver camel, which was exposed to a possible frame on f3. OpFor declined to frame the camel on 16g, which was probably a wise decision as it would have been extremely difficult to rotate the elephant out of the frame.

OpFor vs. Zombie after 43s ee3e ef3w Df2n df1n

Zombie continued to send reinforcements into the south, then advanced a very dangerous-looking rabbit to the a2 square with its 18th move. Because OpFor had to focus on stopping the rabbit, a gold rabbit was hung out to dry on the b3 square and was captured by the silver elephant on 20s. If silver could play Hb2n ec2w Cc1e hb1e on 21s, the game would be decided immediately. Thus, on 21g a gold rabbit was thrown on the sacrificial altar at d6 so that the gold goal threat would delay the silver pieces just enough to avert disaster. After the gold rabbit was captured on 21s, Zombie was ahead by a cat and rabbit but OpFor was able to stay alive with its 22g. By move 24, the silver rabbit had been pushed back to a3 and the gold elephant had ample time to return east to challenge the silver camel again. Although the silver camel eluded capture, OpFor scored a major gain by pulling the horse into the f3 trap on 27g. Zombie prevented further losses by once again threatening a goal in the west and luring the gold elephant over.

After being at a disadvantage throughout the entire opening phase, OpFor seized the initiative on 30g, advancing a strong rabbit to b4 and threatening to take the battle into the north half of the board for the first time. The silver elephant raced home to stop the advancing gold rabbit, leading to a curious position on move 33 in which each elephant froze an enemy horse and rabbit, mirroring the opposite side. Zombie created a new goal threat in the sparsely defended southwest with a rabbit advance to b3 on 37s. A couple of gold rabbits slid over to the c1 and d1 squares, enough to stop the immediate threats. One silver rabbit darted down to d2 on move 39, but the nearby gold horse put a stop to its aspirations. The momentum swung back into OpFor’s favor on 42g when it pushed the silver rabbit down into the c3 pit. Zombie appeared poised to take back the lead on 43s with a gold dog frame on the f3 trap, however the gold horse pushed a silver rabbit onto e4 which stonewalled the silver elephant. It all went downhill for Zombie after that move, chiefly because the silver elephant was completely blocked out of the north half of the board. The elephant finally made it back to its home turf on 48s, but only after the loss of a cat and a gold rabbit had reached a6. On 50g, after the elephant stopped the gold rabbit, a gold cat pushed a silver rabbit down the c6 hole. The final nail in the coffin came courtesy of a second gold rabbit that raced up the d-file on 51g. Unable to stop the dual rabbit threats, the silver elephant could only watch as a rabbit snuck past to the 8th rank on move 53. OpFor’s wild, come-from-behind victory was by far the most dramatic and exciting of the first round. Hopefully the 2009 Computer Championship produces many more great games like this one!

bot_Badger vs. bot_Bomb2005CC

In the opening Badger managed to get one of Bomb's dogs pulled out down the H file while giving up a cat hostage held by a horse on g6. While Badger attempted to get the dog back to its own side and free the cat Bomb was able to get a hold of Badger's camel and push it up the D file. In an effort to save the camel Badger brought a cat to c5. This prevented the immediate capture of the camel while allowing Bomb to re-establish the cat hostage and complete the camel hostage.

Bomb was able to quickly capture the cat at f6 and bring a horse down to the G file preventing Badger from bringing the dog back to f3. Bomb then worked on taking control of the c3 trap and setting up a goal threat by f3. This allowed Badger to take control of, and capture a cat at, f6 with a horse and dog by 19g. Bomb then strengthened the goal threat to the point that there were only a few moves that would prevent immediate goal. Unfortunately this triggered a previously unknown bug in Badger where it can crash if there are less losing moves than processors that Badger is running on. Resulting in the win for Bomb on 19s after Badger failed to send a legal move.

Round 2

bot_GnoBot vs. bot_OpFor

GnoBot vs. OpFor after 24s ef5s ef4w Cf3n re8e

GnoBot opened the game with a dog pull to the d5 square on 4g. OpFor got into positional difficulties by move 5 and then decided to give up the dog in return for a gold cat on 7s, plus the initiative to launch an Elephant + Horse attack in the southwest on 8s. However, the decision to push the dog west, rather than south or east, was a tactical mistake that allowed the gold camel to immediately freeze the attacking horse at b3. The silver horse did manage to escape and it participated in a new E+H in the southeast on 12s. This time, the gold elephant dragged the horse away, leading to an exchange of horses on move 16. The other silver horse then pulled a gold dog up to g5 on 20s while GnoBot pushed the silver camel into the southwest. OpFor passed up an opportunity to capture the gold dog on 21s which would have put it ahead by one cat. Instead the silver camel, threatened by a potentially useless frame, used all 4 steps on 21s to flee to d1. The gold camel also responded with 4 steps on 22g, moving to g4 to save the hostage gold dog. The silver elephant intervened, threatening to capture both the gold camel and dog after 23s. After the gold camel was saved from danger, the gold elephant pursued the silver camel which led to an unusual exchange of silver camel and silver rabbit in return for 2 gold dogs and a gold cat. Because of the first unbalanced exchange of the game, GnoBot had effectively captured the silver camel and rabbit in return for 2 cats and a dog, with an additional dog and horse removed from each side after 29 moves. It’s unclear which side had the material advantage at this stage, as there are differences of opinion on such an imbalance, but the positional considerations certainly seemed to favour GnoBot. As the game unfolded, the silver horse was neutralized on the east side by the gold camel while the gold horse was a major force in the west.

The silver elephant infiltrated to g2 on 32s, threatening a goal-in-one. The plan could not work, however, as the gold camel and rabbits were easily able to halt the threat. Stopped in the southeast, OpFor now had to defend in the north where the gold elephant was threatening its pieces. It chose to give up the f8 rabbit with the 34th move, though it’s not obvious why it declined to place a dog or horse on the f5 square instead. Stymied in the south, the silver elephant returned to the north, captured a gold rabbit in the f6 trap on 37s at the cost of a silver rabbit in f3. It was the beginning of the end on 38g as GnoBot advanced its horse up to the undefended c6 trap, preparing to advance a rabbit in the open west. When the gold elephant joined in on 41g, it quickly worked with the horse to dominate the northwest and a rabbit scored up the c-file two moves later.

bot_Bomb2005CC vs. bot_clueless

bomb vs. clueless after 23g de6s Me7s Hd1n Hg3n

Each bot set up with a variant of the 99of9 setup, but Bomb's deviation of starting with a dog on one corner quickly proved disadvantageous as it permitted clueless to launch an elephant-horse attack against the c3-trap on move 4s. The next move clueless' advanced horse ducked out with a rabbit pull, apparently fearing to be taken hostage by Bomb's elephant, but clueless' horse changed tack and jumped right back into b3 on move 6s. On the next two moves clueless not only left its horse on b3, but also cemented it with a rabbit advance, daring Bomb to take it hostage. Bomb finally tried to take the advanced horse hostage starting on move 9g, but bungled the procedure, allow the horse to escape up the middle with a cat which it captured on 11s.

Bomb chased clueless' camel, threatening to take it hostage on 13g, but clueless coolly ignored the threat and re-established control of c3 with elephant and horse on move 13s. Bomb chickened out of its camel hunt and took the invading horse hostage, properly this time. However, in the process Bomb released clueless' camel, which pulled Bomb's dog offside. To prevent loss of the dog, Bomb ceded control of c3 and counter-attacked c6 with elephant and dog. The counter-attack was too weak to gain control of c6, though, so in order to have a threat to match clueless' threat, Bomb raised the stakes further and attacked f6 with camel and horse (see diagram). On move 23s clueless correctly ignored Bomb's counter-attack, captured a rabbit in the c3-trap, and reached goal two moves later.

The way the top seed clueless manhandled Bomb was quite a shock compared to Bomb's dominance of every past Computer Championship. It remains to be seen whether Bomb can bounce back against other bots and earn a re-match against clueless.

bot_Rat vs. bot_Zombie2008CC

Rat started out very well and by move 6 had obtained a camel hostage. Unfortunately it then had no idea what to do and slowly lost ground. By move 15 it had almost lost hold of the camel and had its elephant effectively smothered.

At that point, as happened in its round 1 game, Rat seemingly went into an infinite loop and lost by timing out.

bot_Badger vs. bot_Sharp2008CC

Rookie of the tournament bot_Badger faced 2008 runner up bot_Sharp2008CC in the final game of round 2. Badger opened with a conservative line up having all rabbits back. Sharp responded with 1 rabbit forward and camel on a corner.

The first few moves saw lone elephant attacks with Badger attempting to pull out a silver dog from central file. Sharp took precautions to save the dog and also started advancing strong pieces for attack on the west side. Badger then made an unusually bold move by fully committing to attacking the NE trap with camel winning prospects.

Immediately the game went into trap contention by both sides, with Sharp attacking SW trap with an E-H and Badger responding with E-M attack on NE trap. Quickly horses were exchanged, but Sharp found itself in a miserable position because of its threatened and cornered camel.

Instead of bringing back the elephant for rescue, Sharp made a clumsy 9s by moving its elephant further into the SW corner. This resulted in Sharp then throwing away 3 of its rabbits to save the camel. Sharp finally sent the elephant to the NE and had a strong position on Badger's SW trap on move 13g. When Badger found the material loss in the SW unavoidable, it promptly brought back the elephant offering a camel exchange on 15g. Sharp accepted the offer and also captured a gold rabbit decreasing the material imbalance to 2 rabbits.

When Badger's elephant was taking full control in rescuing further material loss in the SW, Sharp piled up almost all the strong pieces on the west side. At 20s Sharp rounded up a cat ensuring its capture leaving the east side completely open.

Voila Badger grabbed this opportunity nicely sending a horse to the empty NE corner and threatened a cat itself. Totally oblivious of goal defense Sharp captured the cat and saved its own, but further opened up the NE corner.

In what appeared to be a swindle 22g, Badger cleared a way for a rabbit on the west side for a goal in one even though it was easily stoppable. Sharp recognized the goal in one and stopped in the west side but didn't attempted to do anything on the east side. In 6 secs, badger found a goal in 2 and marched to victory on 25g.

In one of the greatest upset of computer championship so far, bot_Badger completely outplayed the bot_Sharp in tactical strength and goal search. bot_Sharp is hanging on the edge now with 2 losses and is in a must win situation for Round 3.

This game is an utter display of the general strength of newly improved bots over the previous year's bots.

Round 3

bot_Zombie2008CC vs. bot_Bomb2005CC

Zombie vs. Bomb after 16s rb8s hd5n hd5s

Zombie started with a standard 99of9 setup while Bomb lined up with an imbalanced setup with 2 horses on the east side and dogs on the wings. Zombie quickly took advantage of Bomb's unusual setup and attacked with E-H. Bomb managed the situation taking the attacking horse as a hostage.

Since Bomb's elephant was immobile holding the horse hostage, Zombie further propped up the attack. Zombie's M and H attacked on the west side and rabbits advanced on east partially blockading Bomb's elephant. On 8g, Zombie successfully occupied all the traps. When Bomb was struggling to get the situation better, Zombie flipped Bomb's cat using its pinned elephant and pulled it to f4 for capture in the next move. Bomb made a poor move bring another cat to save the first cat at f4. Zombie rightly brought a dog up and both cats were captured by 16g.

Up by 2 cats, Zombie pursued Bomb's horse. This prompted Bomb to abandon the hostage and alleviate the situation. Then Bomb slowly and cautiously started attacking Zombie's east side with M-H. At 20s Bomb took complete control of Zombie's east trap and started to threaten pieces. This move also opened a choice for exchanges. Though Bomb's threat can be easily thwarted and could have been used for rabbit advance, Zombie decided to go for exchange.

Bomb proved Zombie's decision wrong and in the ensuing exchange captured Zombie's camel and a horse, giving away only a rabbit and horse with a strong position. Zombie further crippled the situation, forcing itself with another bad exchange losing horse for dog on 27g.

Bomb, having M-H for Zombie's DCCR, was ahead positionally and poised to win more material. Soon Zombie lost a dog on 32s trying to save material elsewhere. On 38g Zombie resorted to goal chase trying to sneak in a rabbit. With more pieces for defense and superior goal defense Bomb curbed all the goal attempts by Zombie and started its own attempt for goal. On 46s Bomb found goal in 2 and won with elephant sacrifice.

With superior tactical skills Bomb came from behind and finished the game with style.

bot_Sharp2008CC vs. bot_Rat

Sharp started the game with a lone horse attack on the east in response to an unbalanced setup by Rat. When Rat brought the camel from the other side, Sharp converted to EH attack on the east and advanced the horse on the west side. Soon Sharp maneuvered an exchange on 7g offering to capture a dog and camel giving away 2 horses. After capturing a horse for dog, Rat declined the second exchange. But in doing so, Rat exposed the camel that was promptly taken hostage. Sharp then propped up the attack on the west wing sending the camel to accompany the already advanced horse.

Seeing the position getting worse on west side, sharp brought back its elephant offering a camel exchange. Rat declined again and the ensuing tussle had both bots taking a camel hostage on the east side on 13g. Rat made an extraordinary move on 14s capturing the camel by sacrificing its dog. By this Rat forced a camel-dog exchange for a camel-horse. At this stage Rat was materially superior having 2 horses for Sharp's 2 dogs.

Rat didn't made use of the extra horses very well and started attacking without adequate preparation, giving enough time for sharp to advance rabbits. On 23s Rat took control of Sharp's west side home trap and Sharp responded with a goal threat.

After exchanging rabbit-dog for rabbit-cat at 27g, Rat was still at a better position. Immediately game went into a thriller with goal chase on either side. But Sharp proved to be much superior on the goal attack and even with some sparkling defense by Rat, Sharp burrowed into the 8th rank on 39g.

bot_OpFor vs. bot_Badger

OpFor vs. Badger after 5s ed5e ee5e ef5n dc7e

After a splendid performance against bot_Sharp, bot_Badger faced bot_OpFor, a bot with intuitive opposing force. OpFor started the game having all rabbits back and a balanced front row with horses on the wings. Badger had 1 front rabbit on the west corner and a horse on the other corner in an otherwise similar setup.

OpFor vs. Badger after 25s ce6s ce5s Re3w ce4s

The game proceeded with a lone elephant attack by OpFor in the center and dangerous advancement of pieces in the west wing by Badger on 3s. OpFor, instead of towing away and capturing the nearby cat, advanced horses on 4g hoping to storm the east wing with an E-H attack. When Badger further advanced pieces on the west wing, OpFor took a nice control of the Badger’s east side trap with E-H. Badger made a very impressive move on 5s leaving its elephant right inside the f6 home trap in between OpFor’s Elephant and Horse, thus holding the horse in an unavoidable hostage.

OpFor made some futile attempt to recover the situation then resorted to rabbit pulling on the east wing. By 9s Badger successfully completed the horse frame and freed up its elephant. OpFor decided to lose the horse and started pulling the framing horse. Up by a horse Badger made another bold move on 10s advancing and bringing the camel from east to west and hanging right near OpFor’s c3 trap. It was a fully committed attack by Badger with a plan to swarm the west wing. The rabbit pulled by OpFor earlier helped Badger to thwart the camel hostage attempts by OpFor. Badger completed the swarm by 12s partially blockading the elephant and making the position worse for OpFor.

Since the position in the west was deadlocked, OpFor rightly activated its camel and started attacking the east side. After some tussle OpFor managed to pull out Badger's pieces to its home trap and took a horse hostage. Badger started advancing a slew of pieces in the east hoping to escape the situation. When nothing helped and material loss was inevitable, Badger brought back the elephant for rescue on 20s, threatening to capture the dog at the same time. Badger's elephant went back to keep up the west side swarm when OpFor saved the dog and didn’t made any immediate threats.

The next few moves saw a lost opportunity for OpFor, failing to capitalize on the situation. It floundered tactically in getting a hold of badger's pieces that were alarmingly dispersed on the east. This included an unnecessary move on 24g. Opportunity lost is opportunity gained for Badger. By 25s Badger formed a stronghold alliance of small pieces and framed a rabbit on OpFor’s home trap. OpFor was helpless and hopeless allowing Badger to further strengthen its position. By 29s Badger’s elephant joined the east side attack making it a dire situation for OpFor.

The game was almost over at this stage with Badger having a resounding hold on all traps. With OpFor's camel running away to take cover, Badger started capturing piece by piece. OpFor's attempt to get some play on the west side with the suddenly woke up elephant, though managing to capture a rabbit, didn’t have much impact. The situation was far worse on the east side and Badger started the goal attack on 38s. OpFor lost further material in a valiant attempt to stop goal. After almost clearing OpFor's entire army, Badger swept the goal on 58s proving OpFor's Opposing Force is not good enough to stop Badger's bothering force.

Round 4

bot_Zombie2008CC vs. bot_Badger

After a stellar performance winning 2 games in a row, bot_Badger faced the brainless bot_Zombie2008CC. Zombie already lost 2 games, was on the verge of elimination and had to win this game.

Zombie opened with 99of9 setup and Badger repeated the same opening it used in the previous games. For an immediate E-H attack on west side by Zombie on 3g, Badger responded poorly by hanging the camel on f5, making it easy for a camel hostage. Zombie's attempt to take over the camel was not efficient and it shifted the attention to the east side with an M-H attack.

The M-H attack by Zombie was not efficient either with many unnecessary steps. Meanwhile Badger completed a horse frame at its west side home trap on 9s with all heavy pieces E-H-M. Though having a strong position on the east side, Zombie continued to make random moves. Badger managed to sneak a dog from the west side and was trying to disband pieces on Zombie's west trap. It was funny to see Badger's lone dog on the west side manage to win a cat while Zombie's M and H managed to win only a rabbit on the east side.

At 23s Badger effectively used a rabbit that was dislodged from the east by Zombie, for a goal threat on the west. Again Zombie displayed its inability to defend goal and used the move 24g to capture Badger's horse instead. Badger immediately found a goal in 2 and recorded its 3rd consecutive win on 25s.

More than Badger's win this game exhibited bot_Zombie2008CC as a true Zombie.

bot_Bomb2005CC vs. bot_GnoBot

GnoBot finally hit pay dirt with its opening book and did so in a spectacular fashion, when Bomb started out with the exact same setup it had played and lost with against Clueless in this same tournament two rounds ago. Running on the same, dedicated hardware left little room for any chance of deviation for the deterministically playing Bomb and sure enough, the game ended up being an exact duplicate of the aforementioned encounter with Clueless. Bomb is now on the verge of elimination in a championship that up till now, has known no other winner.

Postscript: After this game was played it was discovered that a configuration file had been missed when moving Bomb to the CC server. The Tournament Director then ruled that the game should be replayed. This took place as Game 99124, the result was the same. Although Bomb does randomize its opening setups, there are only four variants, so Gnobot hit a 1 in 4 lucky break in this repeat game.

Round 5

bot_Clueless vs. bot_Badger

Badger set the tone for the game on move 2s by senselessly advancing a dog to the fourth rank. When Clueless logically used its local horse to threaten the exposed dog, Badger was already forced to lose material. The tactical sequence ended with Badger down a cat and a rabbit, with only a glimmer of positional compensation from framing clueless' horse in f6.

Clueless next pulled a rabbit offside with its camel, which induced Badger first to give up the horse frame to save the rabbit, and then to give up the rabbit to re-establish the horse frame. Immediately thereafter, however, Badger again released the horse frame, allowing clueless to resolve its strategic problem by offering a horse trade on move 13g. When Badger inexplicably refused the horse trade, clueless unleashed a nifty tactical sequence to net a cat, after which the horse trade happened after all.

In the moves 20 to 22, Badger again badly stumbled tactically giving up its remaining horse for a camel hostage that clueless was quickly able to release. Badger timed out on move 24, which proved to be a mercy because it was behind by a horse, two cats, and two rabbits, and faced an unstoppable goal.

bot_Bomb2005CC vs. bot_OpFor

Bomb vs. OpFor after 30s hg4n Rg6n hg5n ma5e

Bomb took the early positional lead due to a badly place silver rabbit on c6 after six moves. OpFor’s elephant had fewer prospects in the opening phase, but things turned around in a hurry thanks to some inaccurate play by gold. The gold camel was left exposed and eventually fled to the “safety” of the e6 square on 9g. The silver horse froze a gold cat at c4 on 9s, meaning that gold had two precariously positioned pieces. Bomb solved both problems with its four steps, shifting the camel to c5 thereby protecting the cat and threatening the silver horse. The risks inherent in the gold camel’s travels to e6 and c5 became apparent on 11s when it was frozen to the a5 square. The gold elephant tried to shield its camel from danger, but OpFor was willing to discard a silver rabbit to renew the threat. An unusual struggle commenced in the corner of the board on move 13 when both elephants and the gold camel fought for position. Though the camel wouldn’t have seemed to be in any real danger if the gold elephant simply stood on b6 on 14g, Bomb was determined to keep the camel on a8. After a back and forth struggle between the two elephants, the gold elephant made a disastrous advance to the c7 square on 18g. OpFor immediately blockaded the unfortunate elephant on c7 from whence it would not move again! The only consolation for the gold side was the capture of a second rabbit in the c3 trap.

As two rabbits are hardly worth the price of an elephant blockade, OpFor quickly controlled the entire board. It was a bit reckless (overconfident would be the adjective if it were a human player) on 28s, as it advanced a silver horse to e3 with c2 possibly being the next intended destination. That could have given silver an iron grip in the west, but the eastern half of the board was left in an anemic state. A gold rabbit advanced menacingly to h6 on 29g. On 30g, Bomb had two aggressive options at its disposal: horse to g5, or (as actually played) horse to f5 and rabbit to g6. With the selected move, the gold horse had a great chance to sacrifice itself by pushing the cat off the e7 square on 31g. Though the silver camel could have frozen it in place on 31s that would have freed the other gold horse to both liberate its elephant and threaten the c4 silver dog. With a golden opportunity to turn the tables on OpFor, Bomb inexplicably charged it horse directly at the silver camel on 31s!! Perhaps it expected the two gold horses would work together on the west to free the elephant. From a certain point of view that was correct, as the gold horse was framed on c6 – and the blockade was removed from the gold elephant in order to hold the horse frame. Bomb, however, was not willing to give up the framed horse and the elephant stood in place on c7.

With all of the powerful gold pieces reduced to little more than debris in the northwest, the gold cats, dogs and rabbits attempted to generate counterplay in the east. Though, in appearance, Bomb generated some powerful rabbit threats by move 43, the rabbits couldn’t score in the empty northeast because every eastern gold piece was frozen in place. A gold dog leapt free and tried to aid the rabbits over a period of several moves, but they couldn’t make progress against the powerful silver defenders. On the 50th move Bomb had no way to stop the h3 silver rabbit and OpFor finally won the game on its next move. This game signifies the end of an era as Bomb, 28-3 in previous tournaments, bows out after 5 rounds with a 2-3 record. OpFor avoided elimination but faces a tough challenge against undefeated Clueless in round 6.

Round 6

bot_clueless vs. bot_OpFor

Clueless vs. OpFor after 23g Dc5s Eg3w he3w Ef3w

The game opened with symmetrical setups, aside from the customary inversion of elephant and camel. Clueless played a bit tentatively in the opening but still obtained a good position when the aggressive silver camel was frozen to h4 on 6g. The hostage silver camel was pushed down to h3 but OpFor got partial compensation by flipping a gold cat to e4 on 7s. Rather than focusing on the cat, OpFor got greedy trying to threaten a dog as well on 8s. With both elephants tied to f3 trap, the horses, dogs and cats battled it out in the middle of the board for a few moves and after the smoke cleared on move 12 each side had captured a cat. The silver army didn’t have time to swarm the gold elephant that stood on g3, but with two pieces on e3 and f4 it was enough to allow the silver elephant to rotate to d3 on 14s.

The level of complexity (and excitement!) got ratcheted up a few notches on 18s as both the gold camel and a horse were threatened in the c6 trap. Clueless fought tooth and nail to keep its pieces alive, threatening the silver horses around the f3 trap and advancing its pieces where necessary to keep the camel safe. The gold camel fled to e8 on move 22 and so the silver elephant shifted its focus to the gold horse. In big trouble in the north, Clueless began to fight back around its own traps, pushing a silver horse to d3 on 23g. At least 4 plans were available to silver: (i) advance the dog to b3 and move the camel to g3 (ii) flee north to safety with the eastern silver camel and horse (iii) capture the gold horse and give up the d3 silver horse (iv) dive down to f2 with the silver camel with long-term intention of holding the f3 trap. As all four plans held promise for silver, OpFor no doubt held the upper hand at this juncture. OpFor decided upon (iii), perhaps the most direct and strongest option, and then quickly forked the camel on d6 on move 24s. Clueless threatened to take the silver camel in response, but the dog seized b3 to maintain silver’s advantage. As a last resort to save the gold camel, the elephant charged up to f7. The camel was indirectly saved thanks to the threat against the g6 horse but the c2 gold rabbit was captured instead. After 27 moves, the gold camel was forked, the gold elephant was badly positioned, a silver dog and camel controlled the southwest and the a5 silver rabbit had a lot of latent potential. Though gold’s prospects seemed bleak and OpFor had played splendidly in the opening, Clueless still had the advantage of being the strongest bot in the tournament.

Clueless vs. OpFor after 35g Hg3e cg2n cg3w cf3x Hh3w

OpFor passed up an opportunity to capture a gold dog on 28s and the gold elephant promptly returned home to freeze the camel. Clueless won a rabbit in the ensuing exchange, evening the material score, but when the silver camel escaped to safety it guaranteed a large advantage for silver. With the gold camel doomed in the north, the gold elephant passed up an opportunity to capture a silver dog on 31g so that a horse could be threatened instead on 32g. Because saving the horse would temporarily allow the gold camel to be freed on the next move, OpFor chose to sink the gold camel immediately and give up its horse in return. A silver cat was captured on 35g, roughly levelling the material situation, but silver still had a powerful positional advantage.

The b2 gold rabbit should have been captured on 35s as that would have enhanced the strength of the a4 silver rabbit and enhanced the camel’s strength in the middle of the board. OpFor made a terrible mistake in passing up the rabbit capture and when it finally did so on 38s the move’s potency was diminished by the gold dog. Silver’s material advantage was increased with an exchange of dog for rabbit on move 41. OpFor made further inaccuracies by needlessly decentralizing the elephant on 42s rather than placing it on c4 and initiating a western rabbit advance. While silver’s play was cautious and weak, the gold army continued to claw out of the hole by threatening the silver dog. The dog was captured on move 46 in return for a cat and then the gold elephant went for the jugular on 47g. With the silver elephant far away from the action, and with no silver rabbits creating any immediate threats in the southwest, the gold elephant charged north with 2 rabbits and a horse for support. When the silver elephant returned home on 49s, Clueless “sacrificed” a horse for dog on 50g, though the resulting material imbalance was no different than it would have been with a dog-for-dog exchange. After struggling throughout the game, Clueless was clearly ahead after 51g as the g6 rabbit had many paths to victory. Too many gold threats built up one after another, and Clueless sealed the deal on 55g. OpFor played some of the most exciting games of the tournament, but is now eliminated with a 3-3 record. Clueless is a perfect 5-0 after this incredible come-from-behind victory.

bot_Badger vs. bot_GnoBot

Badger vs. GnoBot after 32s Rf1w hf2s ef5s rd8e

GnoBot quickly built up a strong position as its elephant went directly for the gold camel with little apparent resistance from Badger. Though several gold pieces advanced in the east, they were not well coordinated and built no tangible threats whereas the camel was in grave danger by 6s. Unable to save the camel, Badger did the best it could by exchanging horses and capturing 2 silver rabbits as a partial compensation for the lost piece. After the gold elephant pushed its way out of play to g6 on 14g, GnoBot made a strong strategic decision to control the southwest with its remaining horse on 14s. When a dog joined the action on 16s it appeared that the silver pieces would easily gain control of the c3 trap. Badger clearly knows how to handle such a situation as it flooded its own trap with small pieces to fight off the stronger attackers. The two sides had a protracted battle for position around the southern traps for the next several moves. The gold horse gave its army a huge boost when it galloped over to b5 on 23s. However, the gold rabbit that had advanced to g5 in its place was more of a liability because it hampered the gold elephant’s mobility. By 26s, GnoBot was no longer able to save its b4 dog – without destroying its position that is – and so it focused on advancing a rabbit in the southeast. The silver dog was captured on 27g, narrowing the material disparity considerably, while the silver rabbit advanced to h2 on 28s. The dangerous rabbit was easily stopped by shifting the home-row wall of gold rabbits one step to the right. The endgame would have become very interesting and suspenseful, except that Badger didn’t understand the importance of flipping the rabbit to g4 on moves 31-33. After 33s it was too late as all the crucial gold defenders were frozen in place and unable to stop the rabbit from scoring on 34s. With the victory, GnoBot will play a match of 2 to 4 games against Clueless until one bot suffers its 3rd loss. Badger exits the tournament with a 3-3 record, quite an accomplishment for such a new program!

Round 7

Only 2 bots remain: Clueless and GnoBot. Each had a 4-0 record against the rest of the field, with Clueless scoring a 5th win against GnoBot in round 3. Thus, the 3rd round game plus the final series will collectively be a "best of 5" series between the two best bots.

bot_GnoBot vs. bot_clueless

GnoBot vs. Clueless after 21g Df3s cd6s Ee6w me2w

GnoBot got into early difficulty when its dog was flipped offside on 5s and then became a hostage on a6 two moves later. A horse had to flee east on 10g, further weakening gold’s western half. Undaunted by its troubles in the west, GnoBot tried to reverse its fortunes by pulling a silver horse to b5 and freeing the b6 square for the fearless gold dog. The dog was immediately pulled up to b7 and Clueless pushed a gold cat to d5 on 13s. Despite having a clear positional edge, Clueless willingly exchanged its “strong” horse for the two “weak” and endangered gold cat and dog, negating all of its advantage. The silver elephant flipped another cat into danger at e5 on 19s, continuing to denude gold’s western half. GnoBot made a bold sacrifice on 21g by allowing its cat to be destroyed in return for an Elephant + Camel attack in the northwest.

GnoBot made a nifty 25th move to block out the silver elephant from b4 and keep the gold camel out of immediate trouble. Clueless made a very interesting 25th move, advancing a cat three steps to d3. Though the cat would have been much stronger on c3, it was also important to use the final step of 25s to advance a dog to e6, thus preventing the gold elephant from pushing the d6 silver dog east. The gold horse pulled the cat back to e3 on 26g, but ceding the powerful g3 square in the process. Clueless declined to place its own horse on g3 on 26s, choosing instead to save the cat with its elephant. That initiated a bizarre series of moves in which the two sides seemed to relinquish advantages to one another before exchanging dogs on 27s and 28g. A further rabbit exchange was possible, but GnoBot declined its opportunity in return for a direct gold attack beginning on 29g. The rabbit was captured on 30g anyway after it gave its life so that the silver camel could safely cover the c8 square. Clueless was ahead material-wise after 30 moves thanks to 2 extra cats and a dog in return for a horse, but GnoBot still had good winning chances thanks to its mighty advanced rabbit. Silver had some tricks of its own, however, and a silver rabbit threatened goal-in-one with a centralized rabbit after 30s. The ending was incredibly exciting as each elephant tried to fight through a crowd of enemy pieces to clear a path for its respective rabbit. GnoBot had a clear advantage (quite likely a forced victory) after 35g as the gold rabbit on b7 now had a visible path to victory via 27 – only a little more necessary work remained. Clueless tried to slow down the gold attack by pulling the gold rabbit to c7 but there was nothing it could do to prevent the score on 38g. Clueless suffered its first defeat of the tournament and now each bot is two victories away from its first ever Computer Championship title.

Round 8

bot_clueless vs. bot_GnoBot

After GnoBot successfully equalized the score by handing Clueless its first defeat of the tournament (thus turning the remainder into a best-of-three for the title) the game in this round got off to a shaky start, when GnoBot timed out early on. Since it was judged that the bot was not to blame for this, but rather the server, it was decided to void the outcome of this game (id 99620) and start a new one, resuming from the last position that was reached before the time-out. This proved to be more trouble than expected and it took several failed attempts (games 99629 and 99630) to get the championship on the road again.

In the eventually successfully played-out game, it almost seemed GnoBot was emboldened by the previous win, as, already on its 2nd proper move, it aggressively attacked Silver's eastern trap with its camel, which spelled a quick end to the opening phase of the game. It also immediately created an interesting tactical situation, in which a silver rabbit was left hanging (3s). Clueless apparently agreed with the assessment that the rabbit was "poisoned" and declined in capturing it - with the gold elephant out of place after capturing the rabbit, the trap would have been open to a pincer attack to be completed by the elephant. Although, it seems that Silver could actually in that case have limited the material damage by "returning" the rabbit and getting the elephant back in time, possibly even taking the enemy camel hostage in the process! - GnoBot raised the stakes further by venturing out a cat while the enemy elephant had a direct route towards the east blocked off. Not daunted when the elephant was recentered, the cat even joined the party at the eastern trap. Further sloppy play by GnoBot eventually spelled doom for the cat and GnoBot was already materially behind on move 8s.

If that wasn't enough, Silver continued to fail to appreciate the danger of advancing a camel in such an early stage of the game and sure enough, Clueless managed to take it hostage without conceding any material in the process (11g). A gold horse and dog did end up being in the danger zone known as the area around the trap opposite of a hostage scene and it seemed that a reasonable trade of the (weakened) hostage camel for those pieces could have been in the cards. Instead, after what looked to be a halfhearted attempt by GnoBot to flood the hostage scene, the gold horse and dog departed the "danger zone". The dog ended up being captured anyway, but not without Silver conceding one of its own as well (18g).

Then GnoBot made the strategic mistake of attacking the hostage trap while the gold camel was still there! Clueless did the obvious and simply took the horse hostage with it (19g). Now, GnoBot's situation was pretty dire, with the additional problem that it only had rabbits in the vicinity for any possible relief attempt in the form of swarming the trap. When a curious gold horse ventured too close to the silver elephant, it looked like the various rabbits nearby turned out to have some use after all, in that this almost seemed to open up the possibility for GnoBot to allow a delaying sacrifice tactic to capture the horse in return for a few rabbits and not give up any of the major pieces (23s). Clueless would have none of it though, and constructed a clever false protection pattern that for Gold would mean a horse trade at worst (24g, see diagram).

Clueless vs. GnoBot after 24g Dd3e De3n Mf2n hg2w

GnoBot's actions did turn out to have some significant benefit after all, when a further fight over the gold horse led to the gold camel being forced to come out in the open and be threatened itself. Together with the gold horse and another piece that had come to the rescue, a gold dog, a fierce fight erupted over whether GnoBot would succeed in neutralizing Clueless's hostage advantage by trading those devaluated pieces for material coming adequately close in value. After GnoBot had sacrificed two further rabbits as a delaying tactic, Clueless was now content in acquiescing to having both camels be captured simply because it would win an additional dog in the process. Quickly after, in a trade involving a horse on each side, Clueless made the noteworthy decision of allowing a further dog-for-a-rabbit trade without there being a real necessity for it (although it does make some sense in that silver rabbits were quickly becoming rare, prized commodities). Equally noteworthy, GnoBot then declined the trade, perhaps thinking that it could get the dog with no concessions at all.

This turned out not to be the case, because the depleted board (with Clueless doing most of the depleting) was seriously starting to hurt GnoBot when goal threats from Gold began to pop up and capture threats had to take a back seat. Silver tried to generate a goal threat of its own, but Gold had a sufficient defense and it only ended up taking the Silver elephant away from where Gold was having a more credible goal threat of its own. After first missing a forced goal on move 42g (42g Cg4n rg6w Cg5n Cg6n 42s ce7e rf6s cf7s cf6e 43g Eg3n Rf3x Eg4n Eg5e cg6s), a desperate rescue attempt by a silver cat coming from the west, another scary silver rabbit doubling the goal attack (through the center in addition to the east), and a late, desperate sprint home by GnoBot's elephant were all not enough to stop a gold rabbit from finally goaling on move 50, which, not surprisingly, happened on the east side, which was where most of the action in the game took place.

Clueless is now just one game away from succeeding Bomb as the computer world champion, whereas GnoBot will need to win just to force a final all-deciding game.

Round 9

bot_GnoBot vs. bot_clueless

GnoBot vs Clueless after 22s cd6w cc6s dc4w ed3s

GnoBot and Clueless used nearly identical setups for this potentially final tournament match, though GnoBot deviated a bit from the normal practice by using a dog on b2 and horse on c2. A silver dog was pushed to c3 on move 6g, but it took gold two additional moves before the piece was securely framed. Clueless pulled a gold dog north on 8s for partial compensation. GnoBot brought the dog back home and then placed it on c4, relieving the gold elephant from the frame. The silver army co-ordinated to exploit the c4 dog: first the silver horse tried to dislodge it via b4. After the gold elephant froze it from b5, the silver camel swooped in from the east to the d4 square. However, the silver camel seemed to be in trouble after being pushed to e4 on 17g. Clueless then set up a blockade around the camel to save it from capture. The silver camel not only escaped but helped push a gold cat into the f6 trap. That was quickly followed by a gold rabbit capture on 20s giving Clueless a 2 piece advantage. GnoBot had some positional compensation after 22g, however, as three strong silver pieces were held hostage in the east while the silver elephant was tied down to the defence of the dog in the west. Clueless used a tactical threat against the c3 gold horse on 22s to keep all of its pieces alive, but after a strong reply on 23g the silver dog could no longer be saved.

With the material position relatively even at a dog for cat + rabbit, the game continued with sharp tactics as a silver horse and camel were continually under siege and a gold dog found itself frozen in enemy territory. GnoBot used its 31st move to force the capture of a silver horse on 32g. However, it was a pyrrhic victory as that allowed the capture of the b3 gold rabbit and a massive positional weakness in the southwest with a looming silver rabbit threat. GnoBot actually allowed the capture of its gold camel on 32s so that the dangerous silver rabbit could be pulled to e4. A wild series of captures followed, after which Clueless held an enormous advantage due to extra material and lots of open territory for the silver rabbits. There were many gaps in the first row that couldn’t all be plugged by gold, and Clueless found a path to victory on 35s. A new bot champion is crowned!

Results

Seed	Participant	Rating	Rd. 1	Rd. 2	Rd. 3	Rd. 4	Rd. 5	Rd. 6	Rd. 7	Rd. 8	Rd. 9	W-L	Finish
1	Clueless	2056	S 8 W	S 4 W	G 2 W	bye	G 5 W	G 3 W	S 2 L	G 2 W	S 2 W	7-1	1st
2	GnoBot	1961	G 7 W	G 3 W	S 1 L	S 4 W	bye	S 5 W	G 1 W	S 1 L	G 1 L	5-3	2nd
3	OpFor	1873	G 6 W	S 2 L	G 5 L	G 8 W	S 4 W	S 1 L				3-3	t-3rd
4	Bomb	1862	S 5 W	G 1 L	S 6 W	G 2 L	G 3 L					2-3	5th
5	Badger	1799	G 4 L	G 8 W	S 3 W	S 6 W	S 1 L	G 2 L				3-3	t-3rd
6	Zombie	1702	S 3 L	S 7 W	G 4 L	G 5 L						1-3	t-6th
7	Rat	1540	S 2 L	G 6 L	S 8 L							0-3	8th
8	Sharp	1494	G 1 L	S 5 L	G 7 W	S 3 L						1-3	t-6th