After six hard-fought preliminary rounds, the eight-player field for the finals has been set. Six of the top eight preliminary seeds qualified, which makes the game room ratings look reasonably accurate. The two high seeds who didn't qualify were fifth seed PMertens, who was forced to withdraw by real-world pressures, and seventh seed jdb, who faced a very tough draw and finished 3-3 with losses only to three qualifiers.

The two lower seeds to make it out of the preliminaries were the eleventh seed omar and the thirteenth seed woh. Those two won dramatic last-round games to eke into the last two slots of the finals. Naveed also won a do-or-die game in the final preliminary round, a marathon that was undecided well beyond move eighty.

The top seeds played musical chairs a bit, which matters because seeding has a greater effect in the finals than it did in the preliminaries. Pairing is now top vs. bottom, i.e. folding pairing rather than sliding. Even so, every player is entirely in control of his own destiny. Preliminary losses have been forgiven, and the format is double-elimination with a clean slate. Whoever can win five games before losing two will be the 2008 World Champion of Arimaa!

Round 1

Adanac vs. naveed

Adanac set up with four rabbits on the second rank while naveed set up all of his rabbits in the back, so it was ironic that Adanac got a rabbit pull in the opening while naveed did not. Naveed used his lone elephant to pull Adanac's camel out to the fifth rank, but Adanac was able to retreat it to the safety of a home trap on moves six and seven, leaving naveed with nothing to show for his pains.

The tactics got more complex around move 10. In compensation for his pulled rabbit, naveed used his elephant to get Adanac's dog offsides in the east, then used his camel to pull out Adanac's horse in the west. Faced with difficulty keeping all of his advanced pieces safe, Adanac chose attack over defense on move 11, leaving naveed with a critical tactical choice. Naveed could have captured Adanac's horse in c6 in exchange for losing a cat in f6 and allowing his eastern horse to be taken hostage. The situation was complex, but apparently Adanac's counterplay would not have fully compensated naveed's material advantage of horse for cat. In the heat of the moment, however, naveed declined the horse capture, and shored up his defense instead. Naveed's decision proved costly, as the ensuing piece shuffling allowed Adanac to regroup and use both his horses to frame naveed's cat in f6.

Naveed then pulled Adanac's western cat to threaten it in c6, but Adanac rotated his elephant out of the f6-cat frame on move 19, just in time to save his own cat. Naveed quickly faced the music and gave up his framed cat in order to fight for control of f6, because otherwise his position would have deteriorated in face of Adanac's free elephant. However, naveed failed to retake f6 before his elephant had to leave to defend c6, essentially conceding that Adanac would share control of both of naveed's home traps for the rest of the game.

While Adanac captured both of naveed's dogs in f6, naveed launched a rabbit up the a-file towards Adanac's thinly-defended southwestern corner. Naveed piled on with his camel and elephant, and Adanac barely got home in time with his own camel and elephant to stop naveed's rabbit on a7. The strongest free pieces were then a pair of horses on each side, which theoretically could have lead to a stalemate with neither player able to make captures. However, since naveed's defense had been thinned to the tune of two dogs, a cat, and a rabbit, Adanac was able to force his own rabbit through by move 39.

99of9 vs. arimaa master

Each side began with a similar formation, with the exception of the gold cats setting up behind the south traps, opposed by the dogs behind the north traps. The threats built up quickly as 99of9 went directly for a rabbit pull with his elephant in the northeast and Arimaa_master charged his horse onto f3 on move 4. After the gold camel slid over to f2, the silver horse pulled out and repositioned for an attack in the southwest. The gold camel shifted back to c2 on move 5, but this time the silver Elephant + Horse attack continued despite its presence. With his horse being pushed northward by the enemy elephant, 99of9 added a defender to d3 and recentralized his elephant, leaving the h7 rabbit untouched. After a few moves of manoeuvring, the gold horse retreated to friendly territory and, by move 12, most pieces had returned near their original positions. Arimaa_master then sent his elephant into silver territory once again, threatening to flip both the horse and camel into the north. After a period of back-and-forth skirmishing, neither side was able to generate any tangible threats through move 21.

On move 22, Arimaa_master registered the first rabbit-pull of the contest with a horse in the southeast. The gold elephant froze the horse on h3, while a gold horse charged up the a-file. When the silver camel began to pursue the encroaching gold horse, 99of9 sent his elephant up to give the camel second thoughts. The silver horse, now freed from the gold elephant, immediately commenced pulling the h-file rabbit up to h4, then returned home. After another series of back-and-forth manoeuvres, gold finally achieved an Elephant + Horse attack at the c6 trap at move 33. By move 37, 99of9 moved his elephant from d6 to e6 to attack the other enemy trap. Though the gold horse was temporarily left unprotected on b6, Arimaa_master had no time to trap it as the silver camel was threatened in the east. When the silver elephant moved east on the next move, a gold horse and dog rushed forward to frame a silver rabbit on c6. As the rabbit was supported only by a cat on c7, Arimaa_master blockaded entry to the 7th rank so that the b6 and d6 gold horses could not infiltrate. On the next move, a gold horse pulled the silver rabbit off the trap to the d5 square, threatening the now-exposed cat on c7, and blocking the silver elephant out of the northwest quadrant. Arimaa_master had to use a second cat to defend the northwest trap and 99of9 responded by moving his elephant back to d6, framing a cat on c6 on move 40. The silver pieces once again blockaded entry to the 7th rank to protect the framed cat, and Arimaa_master captured the first piece of the game – a gold rabbit in the f6 trap - on the same move.

While Arimaa_master drew first blood in terms of material, 99of9 continued to build up the positional pressure. The c6 cat was flipped to c4, leaving both silver cats exposed to immediate capture. Still unable to reach the northwest, the silver elephant moved to d3 to protect one cat directly, while indirectly protecting the other via threats to the southwest trap. Gold responded on move 42 by again using the same silver rabbit to hem in the silver elephant, while also stepping south with the c5 dog to solidify the c3 trap. This opened an opportunity for the silver g5 rabbit to take 4 steps west to temporarily defend the northwest trap, but Arimaa_master preferred a more aggressive counter-attack: he threatened to push a gold horse into the northeast trap. On his 43rd move, 99of9 had the opportunity to trap the c7 cat with three steps, with the fourth step necessary to prevent an immediate silver goal at d1. That would have set up a forced series of moves where gold could have captured at least three smaller silver pieces (plus a fourth threatened), in exchange for the gold horse. Instead, 99of9 chose to protect the horse, and on the following move he levelled the material balance by capturing the vulnerable d3 silver rabbit.

At move 47, still maintaining material equality, Arimaa_master had dug himself out of his positional hole and he even re-claimed the northwest trap with a gold horse frame. On move 51, the silver elephant had given up the horse frame and abandoned a vulnerable silver cat on b3 to pursue a bigger prize: the exposed gold camel on e4. After 99of9 used his elephant to save the camel and Arimaa_master countered by threatening pieces in both western traps on move 52, the position had become quite complex. An unusual silver Cat + Dog attack was threatening the southwest trap, while a gold horse and camel were somewhat vulnerable on c5 and d5, respectively, beside the silver elephant that menaced them from d4. Gold obviously needed to use 2 steps to defend his threatened home trap (placing the invading silver cat and dog in danger), and 99of9 used his remaining 2 steps to protect the g3 square and advance his camel to d6. This was an apparent positional blunder and Arimaa_master immediately framed the horse on c6, with the gold camel pinned on d6. Moving the gold elephant to c7 would have been awkward and would have left the gold camel exposed to potential capture in f6. Therefore, 99of9 was forced to protect the framed horse by occupying the d5 square with his elephant. Interestingly, while Arimaa_master held the frame of the gold horse, it was 99of9 that was able to build a significant material advantage. With all of the strongest silver pieces standing in the north, two silver cats were trapped in c3 by move 58. During the same sequence, only one gold rabbit was captured in f6. With the gold elephant and camel tied down in the northwest, Arimaa_master began to threaten the southeast trap. In order to free up his elephant, 99of9 moved a gold rabbit to d5 as part of four-piece blockade to deny the silver elephant access to d6. Arimaa_master flipped the rabbit to b5, potentially forcing the gold elephant back to d5. Instead, 99of9 flipped a silver rabbit onto d5 where it became immobilized, and the blockade held.

With his 64th move, 99of9 achieved his objective of removing his elephant from the d5 blockade and it came face-to-face with the silver camel on g5. Though the horse frame was awkward for gold, the freed gold elephant combined with the material deficit for silver meant that Arimaa_master had to search for a new plan. The silver elephant broke off the frame then took the gold camel hostage on move 66. The center of the board was congested enough that the gold elephant was unable to protect its threatened horse and camel. Instead 99of9 captured a rabbit, while Arimaa_master pulled the horse into the c6 trap and took a step forward with a rabbit along the lightly defended a-file. Gold sacrificed a rabbit to delay the capture of his hostage camel while attacking the northeast trap in the same move. Arimaa_master did trap the gold rabbit on move 69, but also released the camel hostage to defend f6 with his elephant. At that point, the material was roughly even; Arimaa_master had an extra horse in exchange for two cats. However, after the gold camel escaped, the positional advantage shifted back into 99of9’s favour for the remainder of the game. The camel was able to create threats in the northwest, and when the silver elephant was forced to return, 99of9 took control of the northeast trap. Unable to prevent one of his pieces from being trapped, Arimaa_master lost a dog in f6 on move 72.

With a positional and material advantage, 99of9 began to play more aggressively on both wings. Arimaa_master did capture the advanced gold camel on move 76 but this bought 99of9 a lot of extra time to create goal threats in the east. Though the silver pieces were able to halt the advance of the gold rabbits, 99of9 was soon able to dominate the eastern traps, and soon had an unstoppable attack. After a few more piece captures, 99of9 found a forced goal-in-two on move 89. At 4 hours and 17 minutes, this epic clash was the longest game of the 2008 tournament, and second-longest by number of moves. (GM)

chessandgo vs. woh

Chessandgo opened with an eastern elephant-horse attack, while woh used a lone-elephant attack to harass chessandgo's central camel. Naturally the two-piece attack proved more forceful than the one-piece attack, and on move 6 woh abandoned his attack to defend f6 with his elephant, because chessandgo's e6-elephant and f7-horse were threatening to inflict catastophic damages.

The typical counter-strategy when an enemy horse is behind one's home trap is to send one's camel to take it hostage, but woh instead advanced his camel in the west. Woh's attacking camel was lonely and ineffective on b3, and chessandgo made sure to block it out of b2 with little pieces. Meanwhile chessandgo had rotated his western horse to g5, and threatened to frame woh's defensive eastern horse in g6. Woh averted the frame by flipping chessandgo's dog into g6, but this only freed up chessandgo's elephant to roam, which in turn forced woh's camel to scurry home to saftey.

Chessandgo renewed the horse frame threat in a different way by rotating his camel east. Woh tried some desperate elephant maneuvers to avoid having his horse framed, but only succeeded in digging his elephant into a hole. On move 19, chessandgo perfected a blockade of woh's elephant on f7.

Although each side still had a full box of pieces, the game was essentially over at that point. Chessandgo won a horse with his free-roaming camel, then rotated his elephant out of the blockade, releasing woh's elephant in order to win woh's camel. At a huge material disadvantage, woh defended tenaciously, forcing chessandgo to win almost all of his pieces before reaching goal on move 42.

Fritzlein vs. omar

Fritzlein opened with four rabbits forward while omar set up all of his rabbits behind his pieces. True to the implied intentions, Fritzlein immediately attacked f6 with elephant and horse, and omar defended. However, omar didn't passively wait for Fritzlein's attack to grow. He pulled Fritzlein's horse from g6 back to g5 (retaking g6 with his own horse) and on the next move flipped the intruding horse from g5 to e5. When Fritzlein moved his horse back around to f4, omar advanced his own horse to f5 for a near mirror-image of Fritzlein's attack.

A bit of piece shuffling left omar's g4-elephant holding Fritzlein's h4-horse hostage, and Fritzlein's g5-elephant holding omar's h5-horse hostage. The players kept strategic symmetry by both shifting their camels west. However, when omar shifted his western horse towards the east, Fritzlein broke symmetry by advancing rabbits and his camel in the west. Omar made the standard response of switching wings with his elephant, which sent Fritzlein's camel scurrying for safety.

After a few moves the pieces sorted out to safety, and once again Fritzlein geared up for an eastern elephant-horse attack while omar's elephant defended. The difference now was that Fritzlein's a4-rabbit was threatened by omar's camel. This provoked Fritzlein on move 19w to make a kamikaze camel advance to b6. When omar sensibly switched wings with his elephant again, Fritzlein tried to hide his camel away on a7 while intensifying his attack on f6. Omar's excellent move 20 totally refuted Fritzlein's plans; he pulled Fritzlein's a4 rabbit to a6, blockading Fritzlein's camel, and freeing omar's elephant to return to the east.

With the help of his elephant, omar picked apart Fritzlein's eastern attack, taking both the attacking dog and attacking horse hostage. By move 23, Fritzlein could no longer contest both of omar's home traps, and if omar's camel had taken Fritzlein's attacking horse hostage, omar stood to win a dog addition to having Fritzlein's camel blockaded. However, omar's move 23 was tactically inaccurate, allowing Fritzlein to dislodge omar's camel and threaten captures in c6. Omar had another chance to capitalize on Fritzlein's disorganized position by stationing his elephant on d6 on move 26, but again omar failed to find the tactically devastating move, and Fritzlein escaped with losing horse and dog in exchange for omar's camel.

Normally a camel is approximately equal compensation for a horse and a dog, but Fritzlein's camel was still blockaded on a7, giving omar a large positional advantage as of move 30. Fritzlein rotated his remaining horse to g6, hoping for a tactical opportunity involving simultaneous threats in f6 and f3, but he missed his best chance as omar rotated his elephant out of the blockade of Fritzlein's camel, and arrived in the east on move 38, just in time to stop Fritzlein's tricks.

Fritzlein then sent his dog west in hopes of digging out his blockaded camel, while omar started rolling a goal attack in the east. Timing is critical in such affairs; omar judged his goal attack would not be quite fast enough to win immediately, and thus used his elephant to delay Fritzlein's rescue mission. With Fritzlein's lone remaining horse committed to defend against goal in the southeast, he could no longer contest f6, and omar won a rabbit there. On the other hand, Fritzlein's elephant at long last dug out his imprisoned camel while omar intensified his eastern goal attack. Fritzlein's freed elephant arrived in the southeast in plenty of time to hold off goal.

With omar's elephant in the northwest and Fritzlein's in the southeast, a capture race ensued, with omar winning a dog and two rabbits while Fritzlein won a dog and a horse. After move 51 omar had an extra dog and three rabbits against Fritzlein's extra camel. In the opening that would be near material equality, but with so many pieces exchanged, it was actually a substantial advantage to omar. Fritzlein's only cause for celebration was that his extra camel was at last free and mobile.

Fritzlein flung his remaining rabbits forward hoping for a lucky break, and omar's move 57 proved to be just that, as it allowed Fritzlein to flip out omar's dog and force material gain. In fact, omar's choice of defense gave up a cat as well as a dog, and left the board firmly in Fritzlein's control. From then on omar only managed one desperation rabbit advance; Fritzlein was able to shut down the counter threat and break through to goal on move 70.

Round 2

99of9 vs. Fritzlein

99of9 feinted towards an opening elephant-horse attack in the east, but backed out with his horse, and crossed over to defend with his elephant when Fritzlein initiated a western elephant-horse attack. 99of9's elephant was a bit late arriving on the scene, enabling Fritzlein to push his attacking horse through to c2.

The next few moves were tactically critical. 99of9 brought his camel to d2 on move 9 to menace Fritzlein's attacking horse, and Fritzlein flipped the camel to the center. The next move 99of9 put his camel in the c3 trap, not seeing that Fritzlein could push his elephant through c3, getting 99of9's camel offsides to c5. Faced with a tough choice, 99of9 gave up a camel frame in c6 to avoid material loss in c3.

For the next few moves Fritzlein rotated his camel out of the frame to give himself the strongest free piece. Meanwhile 99of9 began a western swarm until abruptly changing course on move 17 to give up his framed camel in exchange for the horse Fritzlein had left on c2 since the opening.

With the stronger deputy (second-strongest-piece), Fritzlein was content to engage in slow piece-shuffling and rabbit-pulling; on move 25 he captured a rabbit in c6 in exchange for his own rabbit being framed in f3. Fritzlein then opted, rather than giving up his framed rabbit, to swarm the wing with camel and company. The upshot was that as of move 32 Fritzlein had given up his camel hostage on g2, but also blockaded 99of9's elephant on g3.

On move 33, 99of9 tricked Fritzlein into prematurely rotating his elephant out of the blockade, allowing 99of9 to temporarily regain control of f3 and win a dog and a rabbit for a horse. In the aftermath, however, 99of9 left a thinned defense of f3 in order to counter-attack in the west. Fritzlein won back a dog while 99of9 regrouped his defense. On move 41 Fritzlein freed his camel hostage to g1, not anticipating 99of9's clever response to blockade the camel in the southwest corner. However, while 99of9 rotated his elephant out of the camel blockade, Fritzlein won 99of9's remaing horse for a rabbit.

With a large material advantage, Fritzlein slowly tightened his control of the board, missing a forced goals on move 49 and perhaps elsewhere, but picking off 99of9's rabbits in the mean time. On move 59 Fritzlein finally broke through 99of9's thinned defense.

Adanac vs. chessandgo

Though both players used a slightly unorthodox setup, the opening proceeded fairly typically through the first three moves. After chessandgo flipped a dog to d4 on move 4, Adanac left the dog semi-exposed to a potential dog frame. Rather than accept the dog frame, chessandgo positioned for an Elephant + Horse attack in the southwest and allowing Adanac to position for an E+H attack in the northwest. After chessandgo’s 7th move, he had built up a tangible positional advantage, as he had three attacking pieces, versus two for Adanac, and the silver camel was better positioned to harass the gold horse than the gold camel. On the 10th move, with a gold rabbit framed on c3, Adanac pushed away the silver camel, allowing the possibility of a long-series of exchanges. Chessandgo declined the exchanges as the gold camel would have been able to escape capture. Adanac blockaded the d2 square and pushed the silver camel away from the attacking horse on move 11. Chessandgo responded by flipping the framed gold rabbit to e3, threatening the c2 camel directly. The gold camel fled to safety while the silver camel was pushed east again by the gold elephant. Chessandgo decided to exchange pieces on his 12th move, capturing a gold rabbit in exchange for his c7 cat.

With his cat threatened on f3 and a dog exposed to capture in the southwest, Adanac opted to threaten a silver horse and dog in the northwest, using the 4th step to protect the cat in the southeast quadrant. Chessandgo responded by charging his camel towards the gold horse with his 14th move. Adanac temporarily fought for control of c3 on move 15 to save his endangered dog and rabbit, though Chessandgo easily recaptured the trap, and re-threatened the gold camel. The gold camel fled to safety on move 16, and a threat against the silver camel indirectly protected the d2 rabbit. Chessandgo finally obtained the horse hostage with his camel and he threatened the gold camel yet again. The gold camel fled then west and a horse moved to e3 to protect the d2 rabbit (and threatening to pull the d3 silver dog into the southeast trap). After that 17th move by Adanac, the board position was very unusual as many strong pieces were standing on the a-file, while the entire eastern half of the board had only a horse, 3 cats and rabbits. Silver’s 17th move was used to free his dog from capture, and Adanac responded by re-claiming the b6 square for his horse. Chessandgo had the option of re-defending the c6 trap or exchanging rabbits on move 18, and he chose the latter.

Adanac’s 20th move was a major error – moving the horse to d6 would have blocked a rabbit advance and temporarily threatened the c6 trap. Chessandgo immediately advanced his rabbit to c4, then followed up with another rabbit advance on the next move. Adanac made another blunder on move 22, failing to push the advanced silver rabbit to e4. Chessandgo piled on the goal pressure, advancing rabbits to d3 and d4 on move 22. Adanac overlooked a goal-in-one and the silver rabbit marched to victory on move 23. Chessandgo will face Fritzlein next round in a battle of the two remaining undefeated players. (GM)

naveed vs. woh

Naveed opened the game by advancing his pieces for a possible Elephant + Horse attack while woh sent his lone elephant into the middle of the board. A gold cat was pushed to e5 on silver’s 5th move, threatening both the cat and the f2 horse with immediate capture. Naveed saved his cat with the elephant, while the horse took one step west to avoid being trapped. The gold cat retreated to safety two moves later, and then each side spent several moves pulling and threatening strong pieces. Woh began a multi-piece attack on move 12, advancing his horse to g3. The gold camel pulled and froze the horse to g2 but the attack continued with the silver camel charging down to g3. When naveed brought his elephant down to threaten the invading pieces, the silver camel fled back to its own side. The silver horse could not escape, and naveed flipped it onto the trap square with his g3 elephant. The silver camel then advanced once again, this time to e3, to block the gold elephant from crossing back. Naveed flipped the horse back to g4 but woh responded by pulling a dog up to e4. After naveed rescued the dog with his elephant, woh continued his attack by sending the camel and horse back to the g3 and h3 squares, on move 19. When the gold elephant once again pursued, this time from g4, woh made some clever rabbit pulls to block out the gold elephant from the invading pieces. Finally, after a long positional battle around the f3 square, naveed was able to freeze the horse with camel, and camel with elephant on move 23.

By move 27, naveed had sent his horse into the northeast quadrant to threaten the weaker defenders and prevent his own rabbit from being trapped. Woh, meanwhile had some long-term threats with his h5 rabbit, thanks in part to a strange wall of horse, camel and elephant on f1, f2 and f3 which blocked out new defenders from reinforcing the g1 and h1 squares. On move 31, naveed pushed the silver camel into danger at d2, while the silver horse was frozen on f1 by the camel. Gold’s 32nd move was a tactical error, allowing silver to capture a rabbit on f3 and threatening the silver camel at the trap. Naveed moved his elephant back to defend the trap, allowing the now-unfrozen silver camel to breathe a sigh of relief. Woh followed-up with a second gold rabbit capture on move 33. Another astute move by woh on move 36 doomed the gold horse which stood exposed on f5. While silver used his steps to capture the horse, naveed rearranged his pieces so that the camel could drag a silver horse towards the southwest trap. With his horse inevitably lost, woh used his time to flip a gold rabbit from h3 to f3, opening up a lot of open space for his rabbits to advance.

On moves 39 and 40, woh swarmed with rabbits along the eastern files, with the two badly-placed elephants blocking their path on g3 and h3. With the elephants temporarily out of play, naveed began a multi-piece advance into the middle of the board. By move 46, Naveed solidified his goal defense, adding a rabbit and cat to the g1 and h1 defense, freeing his elephant to move away from some of the clutter. On the same move, Woh captured another rabbit, giving him a three-rabbit advantage (with a horse removed from each side). Naveed then began to pursue a silver dog, while the silver elephant and rabbits continued their southward push toward a goal. While trying to save his dog from capture, woh overlooked the fact that his elephant was very close to being blockaded on move 49. By move 53, woh had managed to save his threatened dog from capture, but naveed had completed the blockade of the silver elephant. With the elephants in the southeast quadrant, both camels behaved like elephants for the next several moves. Naveed once again threatened a silver dog; this time he captured it, though a fourth gold rabbit was acquired by woh as partial compensation.

With the elephants still out of play, woh attempted to drag a dog up to the northwest trap. When naveed saved it with his camel, woh switched to a strategy of general advance. At move 64, a very crucial juncture had been reached. So long as woh had a large material advantage and both elephants were in the southeast, the silver pieces had some good tactical chances. However, when naveed’s elephant began to emerge from the blockade, rotating smaller pieces into its place, woh’s position became very critical. A move such as 64s me3s Rf3w dg6s rg4w could have broken the blockade. Woh chose a different move, which allowed the gold elephant to escape and hold the blockade. Woh then attempted to create counter-play with a rabbit advance, but the gold camel and elephant quickly halted the rabbit and shut down other counter-chances. By move 70, naveed had completely dominated the board, and despite a material deficit, never allowed any chance for woh to challenge his position. Woh’s last gasp was a rabbit advance to e2, blocked only a cat on e1. Naveed was able to stop the rabbit without disrupting his blockade. The silver pieces were then quickly captured one after another until move 92. woh was unable to make a 92nd move because his four remaining pieces were immobilized, and naveed won on the spot. (GM)

arimaa_master vs. omar

Omar opened aggressively, threatening an elephant-horse attack in the east. However, when omar moved his horse off the g-file on move 4, while advancing his western horse as well, arimaa_master advanced his eastern horse to g6 with an immediate capture threat. That might have lead to racing elephant-horse attacks after omar defended f6, but arimaa_master dropped out of his attack and played for a horse frame instead. Omar prevented his eastern horse from being framed, but not his western one, which arimaa_master framed in c3 on move 8.

Omar didn't wait passively for arimaa_master to rotate his elephant out of the c3-horse frame; instead Omar attacked f3 with his camel. Arimaa_master opted to give up the horse frame in exchange for taking omar's camel hostage on move 9. By move 11 arimaa_master appeared to have an excellent camel hostage for no compensation. However, on move 14 arimaa_master failed to defend f6 against capture of his cat that omar had flipped offsides, allowing omar to win a free cat for approximate strategic equality.

On move 17 arimaa_master attacked c6, and omar neither adequately defended c6 nor counter-punched against f3 quickly enough. By the time omar freed his elephant from defense of f3, arimaa_master's MHH had framed and won a horse in c6. Omar's elephant arrived in time to capture one of arimaa_master's attacking horses, but in the mean time arimaa_master's elephant dived through f3 to capture omar's dog in c3, for a net material lead of dog for cat.

As of move 24 the strategic situation was fairly symmetrical, with omar's elephant fighting camel+horse for control of c6 while arimaa_master's elephant was fighting omar's camel+horse for control of f3. Arimaa_master's trap-control tactics proved superior: by move 30 he had secured shared control of c6 with a swarm of little pieces, and was poised to begin mopping up the rest of the board with his elephant.

Although arimaa_master immediately won a horse, omar managed to inject a surprising amount of tension into the position by threatening goal, first in the west, then in the center, and finally in the east. Arimaa_master always had just enough defense, and eventually captured a rabbit in each theater. On move 43 Omar finally regained full control of f6, in the process allowing arimma_master goal in two in the completely undefended northwest.

Omar is thus eliminated, while arimaa_master continues with one life left.

Round 3

Fritzlein vs. chessandgo

The opening of this game was characterized by each player maneuvering his four heavy pieces in search of a favorable alignment, with neither player willing to take a risk and make a strategic commitment. Chessandgo was first to advance a horse on move 4, but brought the horse scurrying home when Fritzlein brought his camel over to threaten it. Fritzlein tried to play against that horse anyway with his elephant, but couldn't bring it close to his camel, as chessandgo's elephant chased Fritzlein's camel from one side of the board to the other and back again in a slow-motion loop.

The first clear opportunity for either player to play for advantage was move 19 when chessandgo could have placed his elephant on g5 to blockade Fritzlein's elephant on g6. It is not clear how valuable the blockade would have been with chessango's camel buried on g7 and Fritzlein's camel active on the other wing; chessandgo declined the opportunity and instead forced an exchange of horses.

The resulting position was tense, as diagonally-opposite horses were threatened by diagonally-opposite camels, which in turn were threatened by diagonally-opposite elephants. Chessandgo appeared to have slightly the best of it by virtue of having rabbits a few steps forward on his camel wing, but on moves 25 and 26 he accepted a camel trade that neutralized any advantage he might have had.

Both players then switched wings with their elephants to menace the opposing horses, maintaining the same kind of tense symmetry as before the camel trade. However, chessandgo was more forward with his dogs and rabbits, which gave Fritzlein a tactical opportunity to trap one of chessandgo's dogs in front of chessandgo's rabbits in the vicinity of Fritzlein's horse. This committed chessandgo to a swarming attack on that wing.

On move 37 Fritzlein freed his elephant from defending the swarm in order to make a material threat on the other wing. This in turn allowed chessandgo to temporarily free his elephant and threaten goal. The tactics were intense for a few moves, but the upshot was that chessandgo could neither force goal nor contest both of Fritzlein's traps simultaneously. Fritzlein began winning material on move 42 and reached goal through chessandgo's decimated army on move 51.

99of9 vs. Adanac

Out of a dual-lone elephant opening, Adanac soon began to swarm in the east, leading with his eastern horse and centralized elephant. 99of9 repeatedly tried to flip the attacking horse into the center, while Adanac tried to bring it back to the g-file. On move 9 Adanac changed tack and sealed the f-file against 99of9's elephant. Ironically, 99of9 flipped the horse he had been trying so hard to centralize from the f-file over to the h-file, but Adanac re-established the f4/f5 wall anyway.

When 99of9 moved his elephant towards the f3-trap and a path to freedom, Adanac continued his eastern swarm while switching his camel to the west and settling his elephant into e3. Adanac's camel poked around in the west, eventually getting a rabbit pull, while 99of9 re-arranged Adanac's eastern swarm, framing Adanac's dog in f3.

Although 99of9's elephant was free to roam while Adanac's was pinned, 99of9 continued to use his elephant in the east while losing his exposed western rabbit. For his pains, 99of9 was rewarded with an even bigger pileup in the east than Adanac's original swarm had created. Only then did 99of9 start hunting in the west with his elephant.

99of9's delay enabled Adanac to threaten to fight for control of c3 in the early twenties, but before engaging the fight, 99of9 opted to re-arrange the east yet again, maneuvering the framed dog from f3 to be a hostage on g2 instead. This lost him so much additional time in the fight for control of c3 that Adanac was able to untangle in the east a bit and win a second rabbit. However, on move 32 Adanac conceded control of c3 and gave back a rabbit in order to nip 99of9's looming western goal threat in the bud.

With threats to Adanac's pieces in both c3 and f3, 99of9 seemed poised to begin winning material. However his choice on move 34 to threaten a cat rather than a camel was questionable, and Adanac fought tenaciously to either take complete control of f3 or generate a goal threat. It wasn't until move 42 that 99of9 finally made a capture, namely a dog in f3, and that came at the price of a monster goal threat around c3 involving Adanac's still-on-the-loose camel. 99of9 defended the threat only at the cost of losing a cat and giving up his own camel hostage.

Suddenly facing the loss of his camel, 99of9 captured a horse in c6 on move 49, but Adanac coolly declined to capture 99of9's camel in response, instead capturing a rabbit in c3 and re-establishing a goal threat. 99of9 defended by putting his elephant into the c3 trap, hastening his demise. Adanac knocked out the supporting rabbit from b3, capturing 99of9's elephant, and brought a rabbit to goal on the following move. This was the second elephant capture of the World Championships, quite bizarre considering their rarity. 99of9 is eliminated by his loss, while Adanac advances with one life left.

arimaa_master vs. naveed

Arimaa_master chose an unorthodox setup, with his elephant and camel on opposite wings rather than in the center. Naveed responded in kind, leaving each elephant facing the opposing camel. The two players attempted to exploit each other's flank camels in different ways: naveed by using his lone elephant to harass arimaa_master's camel, and arimaa_master by angling for an elephant-horse attack on naveed's camel-less wing. Arimaa_master's plan proved the more effective when, on move 7, naveed had nothing better to do than use his elephant to take arimaa_master's attacking horse hostage on the a-file.

On move 9 arimaa_master made an extremely sharp move by occupying d6 with his camel as part of his attack on c6. This resulted in a "frame" of naveed's western horse on b5, although naveed's elephant was not actually pinned to the defense of his horse, since b5 is not a trap square. Naveed had the resource of pulling arimaa_master's a5-horse out of the frame, opening a path to arimaa_master's over-exposed camel. This would have put arimaa_master in straits to avoid a camel hostage, but naveed overlooked his resource on both move 11 and move 12. By the time naveed finally played it on move 13, arimaa_master had taken control of the c6 trap and won a dog while keeping his camel out of the reach of naveed's elephant.

Naveed then chose the inaccurate plan of trying to get his b6-elephant closer to arimaa_master's d6-camel, not by clearing out c6 to go through it, but by travelling all the way around arimaa_master's c5-elephant. This too-slow plan enabled arimaa_mater to retake control of c6 and capture a horse in exchange for giving up his camel as a hostage. Arimaa_master, with his camel now hostage, began the textbook plan of swarming on the hostage wing, a task made much easier by owning an extra horse and dog. He soon freed his elephant and used it to threaten to take control of naveed's other home trap. On move 26 naveed was faced with eventually inevitably losing more material, and had no counterplay, so he effectively resigned by opening a path for arimaa_master to reach goal.

Round 4

Adanac vs. Fritzlein

Adanac set up with his elephant on the b-file, and advanced elephant-horse in the west, but sent his horse home again when Fritzlein moved his camel to defend that wing. Indeed it was Fritzlein who was then probing for some action with his western horse, specifically threatening to take Adanac's western dog hostage. Adanac's elephant brought his dog to safety and pulled Fritzlein's a-rabbit, whereupon Fritzlein seized the opportunity to launch a full-blown swarm and seal Adanac's elephant on the a-file.

On move 10, Adanac was faced with the critical decision of whether to free his elephant north and around the c6 trap, or south and through the c3 trap. He made the incorrect choice of heading north, which kept his elephant out of play for too long, and allowed Fritzlein to take control of c3. Fritzlein won a rabbit and stationed his horse on c2 before Adanac's elephant arrived on defense.

Fritzlein's attacking camel then darted back home to take Adanac's dog hostage on a6, where it had been exposed in the melee. Adanac could have given up his dog and hunkered down to a long defense with a material disadvantage, but instead he played to defend c3 with little pieces while protecting c6 with his elephant and eventually generating a counter-attack on c6. This plan proved catastrophic, for by the time Adanac freed his camel for attack and won a rabbit in c6, Fritzlein had captured two rabbits, a cat, and a horse in c3. Having wiped out Adanac's western corner, Fritzlein marched a rabbit to goal there on move 24.

chessandgo vs. arimaa_master

Chessandgo opened with a western elephant-horse attack, which arimaa_master was content to defend rather than counter-attacking. Chessandgo played for a rabbit pull, not a swarm, and his progress was slow, especially given that arimaa_master several times reversed one of chessandgo's moves, only to have chessandgo redo it and force a deviation. Finally by move 19 chessandgo had pulled arimaa_master's a7-rabbit to a4 and was in good capture position.

Arimaa_master could have let the rabbit go, and banked on losing very slowly at a pace of twenty moves per rabbit, but decided to instead complicate and play for the win. He switched to the east to threaten chessandgo's camel, then switched back to the west when chessandgo re-advanced his western horse. Arimaa_master got some play against chessandgo's western dog, and when that petered out, saved his rabbit by launching an elephant-horse attack on move 28 to compete with chessandgo's elephant-horse attack.

Chessandgo's attack was promising to be the more powerful one, so arimaa_master, after getting his exposed rabbit to the realtive safety of a2, backed his horse out of his attack on c3 to help defend c6 instead. In the mean time, however, chessandgo had gotten arimaa_master's cat offsides and framed it by move 37. Arimaa master's elephant was now pinned to his framed cat, so to help defend c6, he started to move his camel to c8 to harrass chessandgo's c7-horse. Before the camel arrived, however, chessandgo took control of c3 and forced arimaa_master to abandon his framed cat, the first casualty of the game on move 38.

Arimaa_master then had threats around c6 to either use his camel to hold chessandgo's horse hostage, or to blockade chessandgo's elephant, but by move 46 chessandgo had disentangled and brought all his pieces to safety while threatening arimaa_master's lurking a-rabbit. While chessandgo captured the rabbit, arimaa_master finally got chessandgo's western horse held hostage by a camel, but at the same time gave up his eastern horse hostage to chessandgo's camel. Each side freed his hostage horse, but chessandgo emerged with the bonus of taking arimaa_master's camel hostage.

On move 54, arimaa_master used his elephant to prevent chessandgo from maneuvering his camel hostage into a good position, but overlooked thereby that chessandgo's a-rabbit had a clear path to goal on the next move.

Round 5

Fritzlein vs. chessandgo

Both players used the opening moves to activate their elephants, horses, and camels in that order. Chessandgo's sixth move was the first commitment by either player; he advanced pieces to wall Fritzlein's g5-elephant out of the center. Fritzlein responded by advancing his eastern horse to h6, threatening to flip chessandgo's camel offsides. Chessandgo switched gears and retreated his camel to pursue the intruding horse, but couldn't backpedal his entire wall quite fast enough; his dog got pushed offsides by Fritzlein's elephant. In a effort to get sufficient counterplay for his dog, chessandgo blundered on move 7, hanging his f7-cat, which Fritzlein pounced on with his elephant.

In the next few moves Fritzlein recentralized his elephant while his horse was secured as a hostage by chessandgo's camel. On move 11 Fritzlein tried to rescue his hostage horse, but left his elephant on g6 where chessandgo's elephant promptly blockaded it. Fritzlein wriggled his elephant free on the h-file, but chessandgo cleverly permitted it take the long way to freedom while using his camel to capture Fritzlein's exposed horse.

With a solid material advantage of horse for cat, chessandgo began a western swarm, which eventually committed both elelphants to the vicinity of c3. He established his horse on b3 while letting Fritzlein capture a rabbit in exchange. Chessandgo then rotated his horse to c2 and threatened to bring his camel into b3. After an interlude where Fritzlein advanced an eastern rabbit into the center and chessandgo rotated his eastern horse to block it, chessandgo actually occupied b3 with his camel and Fritzlein brought his camel next to chessandgo's c2-horse.

With Fritzlein's camel fighting for control of c3 and his eastern horse captured in the opening, his f3 trap was thinly defended. Chessandgo decided to switch his elephant out of the fight for c3 and into a furious goal attack in the east. On move 31 Fritzlein launched a desperate central counter-attack to generate a goal threat of his own. This netted Fritzlein only a horse in c3 while both of his dogs fell to chessandgo in f3, leaving chessandgo with a material advantage of two dogs for a cat and a rabbit. As soon as chessandgo secured this large advantage, however, he blundered a dog on move 34, leaving Fritzlein with a slightly better material as well as better goal prospects.

On move 36 Fritzlein made a premature western rabbit advance, which merely gave chessandgo an opportunity to regroup defensively. However, in exchange for his western rabbit, Fritzlein got a dangerous threat started in the east with cat and rabbit advancing against only rabbits. Each player also generated central goal threats. On move 44 Fritzlein won a defensive rabbit in f6 while chessandgo captured Fritzlein's central rabbit. This allowed Fritzlein to create an unstoppable two-move threat in the east on move 45. Chessandgo's last gasp was to re-establish his powerful central goal threat, but Fritzlein had one step to delay chessandgo's central threat from four steps to five, while Fritzlein's other three steps insured him an eastern goal on the following turn.

arimaa_master vs. Adanac (third place tie-breaker)

Arimaa_master chose the 99of9 setup with back central cats, to which Adanac responded with Fritz rabbits and back central cats as well. Arimaa_master advanced elephant and horse in the west already on move 3, but when Adanac rotated his camel to the west, arimaa_master bailed out and retreated everything. Adanac took over the role of aggressor, initiating an elephant-horse attack in the east on move 7. When arimaa_master flipped Adanac's eastern attacking horse into the middle on move 9, Adanac responded with a super-aggressive camel advance in the west. After tactical shuffling involving both wings, Adanac's camel emerged with a pulled rabbit, while arimaa_master's camel took Adanac's western horse hostage.

On move 13, Adanac made a bold but questionable decision to sacrifice his eastern horse in exchange for a rabbit capture and a camel hostage in the west. Although this freed Adanac's bothersome horse hostage, it endangered his western dog. Adanac tried to contest c3 with horse and dog while maneuvering the camel hostage into a better position, but arimaa_master found a pretty move 19 to give up his hostage camel in exchange for Adanac's western horse and dog both. This left arimaa_master with a palpable material advantage of two horses and a dog for only a camel and a rabbit.

With the tension resolved, arimaa_master re-balanced his forces to have HDC on each wing. Adanac played for an eastern horse hostage, and when arimaa_master thwarted that, settled for an eastern dog hostage with his elephant on move 25. Oddly enough, three moves later Adanac pulled back arimaa_master's dog in order to re-establish his own dog on g6; in the mean time Adanac had advanced his western camel and started a general rabbit advance. Arimaa_master switched his elephant to the west, accepting the rabbit trade that Adanac seemed to be playing for, and in the process took Adanac's camel hostage.

Adanac faced a desperate situation with his material disadvantage intact and his camel now immobilized. On move 32 he began a quixotic attack in the west, apparently hoping to generate goal threats before arimaa_master could capture the hostage camel in the west. Arimaa_master, both at that point and later in the game, oddly opted neither to win the western camel in exchange for lesser eastern damage, nor to advance rabbits and create a goal threat of his own. Instead arimaa_master was content to play defense and hope eventually to win something for nothing in one of his two home traps when matters came to a head and Adanac's elephant could no longer keep both traps safe. In a postal game, arimaa_master's defensive strategy would likely have paid off without danger. In the live game, however, time pressure began to take a toll on him. Adanac averaged 45 seconds per move throughout the game, only half of his allotment, while arimaa_master used his full 90 seconds, burned through his reserve, and was skirting a timeout throughout the 40's. After much tactical jockeying and further rabbit advances by Adanac, arimaa_master erred slightly in time pressure on move 42 in a way that put his eastern horse in danger. Adanac returned the miniblunder on move 43, with the net result that Adanac won a horse (and freedom of his camel hostage) in exchange for two of his advanced rabbits.

Arimaa_master was then up by HDR for M, still a significant advantage on such a depopulated board. The action was in the east, where Adanac advanced a rabbit all the way to h2 while arimaa_master framed another of Adanac's rabbits in f3 and took Adanac's dog hostage with a horse. To thwart Adanac in the east, however, arimaa_master needed the help of his elephant, which permitted Adanac's camel to dive into c2 on move 52 with goal and trap control threats. Although the position was very double-edged, it appeared that arimaa-master might have the resources to defend the west while creating a goal threat of his own. Unfortunately, arimaa_master lost his Internet connection at that point, timing out. Thus Adanac won the game and third place in the tournament.

Tournament Summary

Combining the results of the preliminary and the final, Fritzlein's 11-0 performance was a convincing tour de force, including eight wins against the second through fifth place finishers. Chessandgo, apart from his three losses to Fritzlein, was 8-0 against the rest of the field for a clear second. Adanac was 8-0 against everyone but Fritzlein and chessandgo, losing once to the former and twice to the latter, so Adanac's claim to third place is clear. However, arimaa_master's came within an ace of knocking off Adanac for third place in the tournament's final game, and would probably have been third place finisher apart from an untimely disconnection; certainly arimaa_master was deserving of fourth place.

The tournament as a whole was a smashing success, both in terms of participation and in terms of advancing the state of the art. Twenty-five players contested seventy-six games, both record highs. The games themselves showed evolving strategies compared to last year, including a greater propensity to advance horses on the wings and keep the camels active on the third rank rather than the second. Furthermore, although it would have been considered madness in 2007 to set up with four rabbits on the second rank, Fritzlein did so in all eleven of his games in 2008, and the setup saw sporadic uptake among other players as well.

Woodworks by Hoodworks

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