Arimaa/Omar vs. Fritzlein, 2005 Postal Championship

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Played over four months, this game ultimately gave Fritzlein a perfect 10-0 record in the 2005 Arimaa Postal Championship. Had Omar won this game, he and Fritzlein would have tied for first with a 9–1 record. The ultra-slow speed allowed for highly tactical gameplay; long-term strategy was still important, but the players had time to work through various sequences and weigh moves that would be risky in a live game.

Game

  • 1g: Omar uses a variation of the 99of9 setup, placing dogs behind his traps. Since a dog cannot be pushed aside by an enemy dog, this alignment limits the ways in which a trap can be attacked, and may even make a dog frame more feasible. A dog might later advance through a trap and be replaced by a rabbit or cat.
  • 1s: Fritzlein chooses the classic 99of9 setup, with cats behind the traps and dogs back and center. This leaves his home traps slightly more vulnerable than Omar's, but losing control of a home trap may be slightly less costly for Fritzlein, as the piece behind the trap is usually the first to go when the opponent takes over.
  • 2g: Omar aggressively advances his elephant four squares, threatening to capture a cat or flip the camel.
  • 2s: If Fritzlein now advanced his own elephant four squares, he would concede a cat but also threaten a dog. Any such capture would use all four steps and create further threats, so this could begin a race with an unclear outcome; Fritzlein would initially capture a dog for a cat, but Omar might still have a first-move advantage. Declining such a race, Fritzlein defends both home traps and shields his camel.
  • 3g: Omar's elephant can't do much where it is now, and could get smothered if it advanced further. Omar thus steps his elephant back a square, and uses his other three steps to develop at home. It would have been faster for Omar just to advance his elephant three squares and a horse one square on 2g; this later became the most popular opening move for Gold, with the horse advance usually occurring on the side where the elephant advanced.
  • 3s: Fritzlein advances his elephant, stepping it east to face Omar's camel. Fritzlein's western horse defends the c6 trap, blocking Omar's horse from b6.
  • 4g: Omar drags Fritzlein's eastern horse towards the f3 trap. While Fritzlein can easily prevent a capture, such threats can keep the opponent on defense.
  • 4s: Fritzlein decides to free his horse before it can be taken hostage. Fritzlein uses his elephant to unfreeze the horse; he could have advanced the h7 rabbit to h5 and unfrozen the horse that way, but the rabbit would have then been exposed. Another option was to step the g7 cat forward, but Fritzlein preferred to return his horse to g6, which could not have immediately happened had the cat been on that square.
  • 5g: Omar moves his horse away from Fritzlein's elephant. So far the opening has been defensive, with non-elephant pieces retreating from threats.
  • 5s: Fritzlein further decentralizes his elephant to pull a rabbit on the h-file. Later Arimaa theory would frown on this, but in a defensive game it may have seemed logical, as a rabbit cannot retreat homeward. Fritzlein could have instead used his elephant to push Omar's e3 horse to d3, thus placing both of Omar's horses in the west, where Fritzlein's camel could have then gone to face them. With no horse in the east, Omar could have been vulnerable there also, and Fritzlein might have gotten strong threats on both wings. Such long-term planning may be more effective than rabbit pulling.
  • 6g: Omar moves his elephant west to make a bigger threat. Fritzlein can hardly continue hunting an eastern rabbit when his western horse and potentially the c6 trap are in jeopardy.
  • 6s: Rather than moving his western horse and thus immediately opening up b6, Fritzlein centralizes his elephant and threatens to flip Omar's e3 horse.
  • 7g: To centralize his own elephant, Omar pulls the b6 horse twice rather than flipping it. Omar could have pulled the horse to b4 where it would have been harder to rescue, but prefers to have his elephant as centralized as possible, so as to limit Fritzlein's progress in the east.
  • 7s: Fritzlein's elephant gets its horse to safety. Continued pull-and-retreat play would slightly favor Fritzlein, since Omar has a rabbit exposed on h4.
  • 8g: In a somewhat more aggressive move, Omar advances a horse to a6; note that the horse advanced on the wing away from the enemy camel. This horse may pull a rabbit, but also threatens to take b6 in a potential trap attack. However, an elephant-horse attack usually requires support from other pieces, and Omar is poorly developed in the west; the c3 trap is even vulnerable to a counterattack. Omar might have done better to first move his other horse back to g3 and his camel to the middle, for flexibility.
  • 8s: Fritzlein could try to bring his camel across to take the a6 horse hostage, but Omar's elephant will not make that easy. Fritzlein could simply take the horse hostage with his elephant, but there is a big difference between a horse-by-elephant hostage and a horse-by-camel hostage. Threatening a mere horse usually does not justify keeping one's elephant in a corner.

    Rather than immediately taking a weak hostage, Fritzlein drags the h4 rabbit further forward, seeing that as a better first threat which might in turn allow for an effective western threat.

  • 9g: Omar could use his horse to pull out Fritzlein's a8 rabbit, but a rabbit-pulling race would not favor Omar at this point. An attack on c6 would be too slow, allowing Fritzlein to capture the rabbit and perhaps even counterattack while still defending c6. Omar thus advances his camel in the east, perhaps intending to use his pulled rabbit to his advantage. An advanced camel is often at risk of being taken hostage, but a supporting flank piece can make this less likely. Increasingly vulnerable in the west, Omar advances a cat to help defend c3; this would not delay an attack for very long, but may give Omar time to attack first.
  • 9s: Fritzlein moves his elephant east to keep Omar's camel under control. Whatever else is going on, an elephant must keep a constant eye on the enemy camel. Fritzlein also drags the rabbit to h6, now threatening it with one-turn capture.
  • 10g: Omar defends f6, placing his elephant on e6 rather than f5. In advancing his camel and dog, Omar moves toward a multi-piece attack on f6.
  • 10s: Unable to capture anything in f6 as long as Omar's elephant defends, Fritzlein moves his camel west, replacing it with a cat on f7.
  • 11g: Omar's horse retreats empty-handed, but his camel advances undaunted, creating an immediate capture threat in f6. With a friendly rabbit on h6, the camel can neither be frozen in place nor taken hostage on h6. No matter how things work out for Fritzlein here, this shows how an early rabbit pull might backfire.
  • 11s: Fritzlein defends f6, and clears room in his back ranks to push Omar's camel to g7, where it could be kept frozen and thus held hostage. Fritzlein's camel inches west, stopping on d6. With Omar's elephant on e6, this does jeopardize Fritzlein's camel, but only if Omar abandons his own camel as well as a rabbit.
  • 12g: Omar would have liked to use his camel to pull a rabbit to f7 or g7, because either move would have deprived Fritzlein of a square on which to hold the camel hostage. Unfortunately, either pull would use all four steps, leaving the a5 horse at risk. Omar retreats this horse, so as not to face capture threats in both c6 and f6. He also steps his camel onto f6, conceding the camel hostage but making it trickier for Fritzlein to set up.
  • 12s: Fritzlein secures the camel as a hostage, albeit in a temporarily very awkward position. Before leaving one's elephant on a trap square, one must double- and triple-check that it is safe; since this was a postal game, Fritzlein had plenty of time for that.

    Fritzlein steps his camel west, no longer offering an immediate trade. With d6 empty, however, Omar's elephant can now flip Fritzlein's cat to e5.

  • 13g: Omar makes the flip. For Omar, capturing a cat might compensate for the disadvantage of having his camel held hostage.

    Now facing an elephant capture, Fritzlein must either get his elephant off the trap or block a step needed for the capture.

  • 13s: Fritzlein pushes the camel to g7; this freezes Fritzlein's horse on g6, but the horse couldn't have moved beforehand, as the elephant would have been lost. Stepping the d7 dog east may be a mistake, as this blocks a potential central hostage should Omar's elephant move to f5. Furthermore, Fritzlein might want to have a dog in the west if he attacks c3.

    13s Mf7w ef6n rc8e mc6e would have effectively given Fritzlein a central hostage, and kept the g6 horse mobile. The camels might have been exchanged, but Fritzlein could have then retreated his cat and gotten a strong rabbit frame in f6.

  • 14g, 14s, 15g: Omar captures the cat, and Fritzlein moves his elephant so that his eastern horse can advance. Omar would now like to swarm f6 and rotate his elephant out of hostage defense. Fritzlein would like to create a second threat and overload Omar.
  • 15s: Fritzlein must move his eastern horse, which could otherwise be flipped to f4 and threatened with two-step capture. Fritzlein advances the horse, but leaves it on a bad square.
  • 16g: Omar abandons his hostaged camel to capture this horse. While a camel hostage-holder often does end up trading a horse for the camel, it is best not to make this too easy for the opponent. Fritzlein could have moved that horse to the h-file and advanced his other horse in the west. Alternatively, he could have advanced his eastern horse to g2. Either way, a horse capture would have then taken Omar multiple turns, in this case allowing Fritzlein to capture both the camel and the rabbit. Had Omar not gone after the horse, Fritzlein could have soon created a second threat.
  • 16s: Fritzlein will capture the camel; the only question is whether to end the move with his elephant on e6, f5, or g6. Since Omar can immediately defend f6, Fritzlein must not keep his elephant in a corner on account of a rabbit. Fritzlein chooses f5 over e6, perhaps wanting to protect the eastern flank.

    Omar is now out a camel, but Fritzlein is out a horse and a cat. While this is close to even, tit-for-tat play will now tend to favor Omar, and thus Fritzlein must play to get ahead.

  • 17g: Eyeing an elephant-horse attack against f6, Omar moves his elephant to e6, blocking a direct path to g6 for Fritzlein's camel or horse.
  • 17s: Fritzlein moves both dogs further east, but a dog is unlikely to hold g6. It is often wasteful to have both dogs on the same wing. A dog in the west could have supported an attack on c3.
  • 18g: Omar advances his eastern horse and a dog behind it, preparing to take the g6 square. It would now be pointless for Fritzlein to flip the h6 rabbit into the trap, as the frame would immediately be broken.
  • 18s: Fritzlein's camel is the strongest piece in the west, but may not have enough support to accomplish anything there. If Fritzlein were to now move his elephant west, Omar might quickly clean up in the east. Fritzlein thus moves his camel east, hoping to restore balance and perhaps take a new hostage.
  • 19g: Omar proceeds with an elephant–horse attack on f6, advancing a dog to keep the horse mobile. Once again, the h6 rabbit complicates a potential hostage for Fritzlein.
  • 19s: Fritzlein's camel moves to take Omar's advanced horse hostage on g7; this would be a double-hostage, as the h6 rabbit would also be threatened.
  • 20g: Omar moves his elephant to f7, pushing Fritzlein's camel west and blocking the possible horse hostage.
  • 20s: Fritzlein moves his camel onto f6, setting the stage for an elephant smother if Omar's elephant remains on f7.
  • 21g: Omar retreats his horse, but his dog and rabbit are still at risk in f6. A strong 21g might have been Ef7w mf6n ce6e Ee7s, which would have centralized Omar's elephant and delayed any hostage by Fritzlein.
  • 21s: Fritzlein now threatens Omar's dog as well as his rabbit. Moreover, an elephant–camel attack on f3 is now possible.
  • 22g: Omar pushes a dog and pulls a rabbit, but this accomplishes very little. Fritzlein can still capture Omar's dog if Omar's elephant leaves the f6 trap.
  • 22s: Fritzlein sets up an elephant smother, which could be completed on the next turn if Omar does not move his elephant west. However, Fritzlein should have added a defender to the c6 trap; it is easy to neglect one area while focused on another.
  • 23g: Omar's elephant escapes, and has a one-turn threat to Fritzlein's b6 horse. A horse capture could make up for a dog and rabbit loss in f6.
  • 23s: Fritzlein elects to save his one remaining horse, rather than trade it for a dog and rabbit. Since Omar has no camel, Fritzlein's horse can only be threatened by Omar's elephant, and Fritzlein sees the value in having two pieces which face only one threat. Had Fritzlein taken this trade, Omar's horses could have then dominated the board.
  • 24g: Omar centralizes his elephant and saves his f5 dog. This was the one and only move that could accomplish both of those things, just as 23g was the one and only move that could create a one-turn counter-threat.
  • 24s: Fritzlein could simply capture the h6 rabbit, but would have to end the turn with his camel exposed. Fritzlein thus moves his elephant to f5 and pulls the rabbit to g6, setting up a solid rabbit frame even if Omar defends the trap.
  • 25g: Omar once again defends f6 with his elephant. Anticipating a trap attack by Fritzlein, Omar defends f3 with four pieces. Omar also steps his western horse to the a-file, perhaps preparing to pull a rabbit; while this is not ideal, Omar does not have many ways to create a threat while defending f6.
  • 25s: Fritzlein frames the rabbit and thus pins Omar's elephant to its defense. Fritzlein may soon attack f3, but must watch the squares around f6 if he wants to keep the frame.
  • 26g: Fearing a camel-held hostage beside f6, Omar moves his eastern horse and dog. However, having one's horse passive in a home corner is not much better than having it held hostage beside an away trap.
  • 26s: Fritzlein develops in the east. The g-file rabbit advances to support its camel, not to threaten goal, as Omar's defense is sufficiently thick at the moment.
  • 27g: Omar pulls a rabbit in the west.
  • 27s: Fritzlein rotates a dog forward with the idea of freeing his elephant to attack f3. With the enemy camel gone and the friendly camel patrolling the east, the dog can take f5, and a rabbit can hold g6. The framed rabbit couldn't retreat to f5 in any case, but Fritzlein's dog will block Omar from relieving the frame.
  • 28g: Omar retreats his e-file cat and dog. However, this gives Fritzlein's elephant a clearer path to e3, from where it could lead an attack on the f3 trap. On e4, the dog was not necessarily in danger unless an enemy piece began a turn on an adjacent square.
  • 28s: Fritzlein attacks the f3 trap, replacing his elephant on f5. Intending to move his own elephant to e3, Fritzlein advances a rabbit to h4 so that his camel can retreat if Omar's elephant comes to f4. For now, Fritzlein's camel should stay on the g-file to ensure that the rabbit frame cannot be relieved from the side. If Omar could get his rabbit off of f6, it might become a strong goal threat, as Fritzlein's recent rabbit advances have thinned his eastern defense.
  • 29g: Omar blockades f3, but such a defense cannot hold for long. Moreover, c3 is now undefended. For Omar, this might have been the time to abandon the framed rabbit and move his elephant south to slow Fritzlein's attack.
  • 29s: Fritzlein threatens Omar's dog in f3 and cat in c3. The cat could be saved easily, but this would use up a critical step.
  • 30g: In three steps, Omar creates phalanxes to protect the pinned f2 rabbit and thus save his framed dog. This leaves a step to defend c3 and thus save the cat also.
  • 30s: The dog flip leaves Omar with only one way to defend f3. A horse flip would have likewise forced Omar's hand, but Fritzlein prefers to keep Omar's horse passive in the southeast.
  • 31g: Omar must move his elephant to f4 and thus give up his framed rabbit. Omar pushes Fritzlein's dog onto f5 rather than e4, so that it can't immediately participate in an attack on the c3 trap.
  • 31s: As Fritzlein planned on 28s, his h4 rabbit allows his camel to retreat. This may be the difference between the camel being taken hostage and the camel holding a hostage.
  • 32g: Fearing an elephant-horse attack on c3, Omar blocks Fritzlein's horse on the b-file. Fritzlein might move his horse through the trap, however, if his elephant goes to d3.
  • 32s: Fritzlein gets his camel safely away from Omar's elephant, which must now defend f6 to save its dog.
  • 33g: Omar defends f6 and shores up the southeast against any possible goal attack. If Fritzlein's camel again went south to attack f3, Omar's dog could become a strong attacker at f6.
  • 33s: Fritzlein threatens to frame Omar's dog in f6; this frame would likely force Omar to give up the dog, as Fritzlein's elephant could otherwise dominate the board.
  • 34g: Omar blocks the frame/capture and retreats his western horse out of immediate danger.
  • 34s: In a mostly defensive move, Fritzlein's camel pushes Omar's dog up to the edge. A buried dog-by-camel hostage is not efficient, but Fritzlein's camel is out of danger, and Omar's dog is stuck in the corner. The downside for Fritzlein is that his camel does not currently threaten either of Omar's horses, and Omar's elephant could now leave without immediately losing the dog. This 34s may be a good move given the position, but previous moves might have been better spent threatening a horse rather than a dog.
  • 35g: Omar threatens a rabbit in f3.
  • 35s: Fritzlein defends f3, and begins to clear space for an eventual dog-capture threat in f6. Advancing a rabbit from f7 may not be wise, however, as this thins his back ranks and exposes yet another rabbit to possible capture in f3. Fritzlein could have instead advanced his horse; an elephant-horse attack on c3 might have outpaced any eastern progress by Omar.
  • 36g: Omar frames the rabbit and thus pins Fritzlein's elephant on e3. It is rarely worthwhile for an elephant to defend a mere rabbit; Fritzlein must soon either give up the rabbit or advance more pieces to the southeast and create a new threat there.
  • 36s: Fritzlein advances his cat, moving further toward a possible swarm of f3. With the cat out of the way, Fritzlein pushes Omar's dog a square closer to f6.
  • 37g: Omar blocks the cat and rotates forward his horse, threatening an attack on f6 which the hostage dog might also eventually join.
  • 37s: Fritzlein finally establishes a one-turn threat to the dog. He also blocks g5 and thus g6. With rabbits now on g5 and h5, however, Fritzlein may face additional losses in f3 if his elephant is forced to leave.
  • 38g: Omar's eastern horse clears a path to g6.
  • 38s: Fritzlein again blockades g5, but Omar can continue to undermine that blockade and perhaps threaten more rabbits in f3. Fritzlein also moves his own horse from b6 to d6, perhaps hoping to advance it through the center. Fritzlein is now vulnerable in the northwest, however.
  • 39g: Omar advances four different pieces, gaining space in the east and preparing an attack in the west. He could have advanced the horse further, but didn't want to tempt Fritzlein's pinned elephant to move.
  • 39s: Fritzlein advances his horse three squares, aiming to either attack c3 or dig his rabbit out of f3.
  • 40g: Omar abandons his hostaged dog and threatens Fritzlein's horse. Omar gains little by stepping his elephant south; Fritzlein's horse is not frozen, and if Fritzlein were to now immediately capture the f8 dog, Omar's elephant could then capture the d3 horse even from d5. Omar could have simply moved his elephant two squares west and advanced his b4 horse to b6, attacking the highly vulnerable c6 trap. Putting off this attack will prove quite costly for Omar.
  • 40s: Fritzlein gets his horse onto Omar's home rank, threatening to dig out the f3 rabbit from behind. The horse was able to escape because it took only three steps on 39s; had it advanced to d2 on that turn, it could have then been frozen in place and threatened with one-turn capture.
  • 41g: Omar now attacks c6. Had Omar started this attack a turn earlier, he could now create a forceful goal threat.
  • 41s: Fritzlein has time to snatch the dog and thus also activate his camel. He will now lose two rabbits, but could not have saved both.
  • 42g: Omar captures a rabbit and advances his rabbit one step, setting up a goal on the c-file. Fritzlein is very weak in the west, and would only lose more pieces if he tried to block the goal on the back ranks.
  • 42s: Fritzlein is forced to defend with his elephant, giving up the f3 rabbit and thus a potential goal threat of his own. For Omar, a goal attack is still feasible, but less straightforward now that Fritzlein's elephant blocks the c-file.
  • 43g: Omar shores up his defense of c3 and tries to prevent a horse hostage beside c6. He temporarily freezes the a5 rabbit, but does nothing to further his own goal prospects on this thinning board.
  • 43s: Fritzlein places a dog on c7, blocking a potential c-file goal even if his elephant goes to b6. He also inches his camel forward in the east; it is currently safe on f6, since the g5 cat can't be pushed east.
  • 44g: Omar threatens a rabbit. However, Fritzlein's horse can defend c3 from behind. Unless a capture can be quickly forced, bringing an enemy rabbit homeward is quite risky on a depleted board. Omar's horse could have instead pushed the dog off of c7, or better yet gone to c7 on the previous turn with steps to spare. This would have made it harder for Fritzlein to block a goal.
  • 44s: Fritzlein takes c2 and eyes d3, blocking Omar's elephant from that square. With his elephant on the d-file, however, Fritzlein could be quite vulnerable to a western goal attack.
  • 45g: Omar finally advances a rabbit past the third rank.
  • 45s: Fritzlein wants to move his camel to g5, but this would require four steps; if Fritzlein does not spare a step to block the c4 rabbit, Omar can advance that rabbit onto c6 and a dog onto c4. With plenty of time to think, Fritzlein calculates that he can ward off such a goal attack, and thus uses all four steps to slide pieces in the northeast.
  • 46g: Facing no immediate threat in the east, Omar presses his goal attack in the west.
  • 46s: Fritzlein steps his elephant back to c5; he cannot get a solid frame in c6, but his elephant must defend goal. Fritzlein uses his other three steps to threaten Omar's eastern horse in f6.
  • 47g: Omar's western horse relieves the frame in an irreversible manner, as Fritzlein's rabbit could never step back to b6. The c6 rabbit is now a strong goal threat.
  • 47s: Fritzlein's elephant takes b6, pushing the horse to b7. This will not be a long-term hostage, but it does limit the c6 rabbit's movement.
  • 48g: Omar defends f6 and creates a one-turn goal threat on the d-file. Omar's b3 cat is now at risk in c3, though Fritzlein does not have time to capture it yet.
  • 48s: Fritzlein stops the d-file goal.
  • 49g: Omar moves his c5 dog south and pulls the c7 dog west, defending both western traps and reopening a possible goal path.
  • 49s: In advancing his dog through the trap, Fritzlein threatens Omar's b6 horse and d5 rabbit.
  • 50g: Rather than defend or delay, Omar offers a horse exchange, which in theory would diminish the influence of Fritzlein's camel and increase the importance of Omar's extra rabbit. Even after this exchange, however, it might be risky for Omar's elephant to go east to face the camel, as Fritzlein might then clean up in the west and get a rabbit to goal.
  • 50s: Fritzlein has little choice but to accept the offered trade, as he can't defend his own horse without giving up a dog in c6.
  • 51g: Unwilling to move his elephant east, Omar now offers his other horse for Fritzlein's western dog. The b4 and d5 rabbits may also be exchanged.
  • 51s: Fritzlein could save his dog and rabbit in the west, but could then lose a rabbit in the east, in which case he would also lose the chance to capture the horse. Fritzlein thus goes for the horse capture.
  • 52g: Omar uses a flip to capture the dog, keeping his elephant positioned for a western attack.
  • 52s: Fritzlein first captures the rabbit, which could have become a goal threat. Omar's horse cannot be rescued on the next turn, so Fritzlein loses nothing by capturing the rabbit first. Now on c5, Fritzlein's elephant can defend his depleted west wing.
  • 53g: Omar's b3 cat captures to c2 so that Omar's elephant can leave without hanging the cat. Considering that Fritzlein's western defense was quite thin, Omar might have done better to flip the rabbit into the trap and thus keep his cat and elephant positioned to support an a-file rabbit advance.
  • 53s: Fritzlein completes the exchange and moves his elephant to d4, keeping Omar's dog in the east. Fritzlein is again vulnerable in the west, but not as vulnerable as he would have been had Omar's cat stayed on the b-file, which would have forced Fritzlein to keep his elephant on defense.
  • 54g: Lacking any effective material threat, Omar threatens goal.
  • 54s: Fritzlein blocks the goal and also temporarily blocks Omar's elephant from d6.
  • 55g: If he can push Fritzlein's dog east, Omar may have a strong western goal threat.
  • 55s: Fritzlein brings his cat to e6, blockading e5 and ensuring that his dog could not be pushed east. He does not move the dog on the fourth step, as that would allow for a capture in c6. Fritzlein's eastern goal defense is becoming thin, but his elephant and camel are well-positioned.
  • 56g: Omar takes d6 and d3. At this point, a rabbit on d3 might do more to stop an enemy goal than would a rabbit on d1.
  • 56s: Fritzlein unfreezes and advances his dog, blocking Omar's goal path and threatening an attack on c3.
  • 57g: Omar moves his elephant east to face Fritzlein's camel. At this point, however, piece alignment is of secondary importance. Fritzlein is poised for a western attack which Omar could not immediately match in the east.
  • 57s: Alert to the risks in both f6 and f3, Fritzlein moves his camel east. His elephant takes d3, blocking Omar's dog. Fritzlein is now well-balanced, with his dog and camel active on opposite wings and his elephant in the middle. Omar is poorly balanced, and must quickly defend in the west.
  • 58g: Omar temporarily defends c3, but leaves it vulnerable.
  • 58s: Fritzlein controls the entire board; his dog can now dominate the west, his cat defends f6 from behind, and his camel is supported by rabbits in the east. Whatever Omar now tries can likely be stopped easily.
  • 59g: Omar hopes to sneak a rabbit to goal. Fritzlein could now capture the c4 rabbit, but then Omar could capture Fritzlein's camel and try to get something going in the east. Even after losing his camel, Fritzlein could defend in the east and attack in the west; this is no longer a material game.
  • 59s: Fritzlein preserves his camel, but leaves Omar the option of taking it hostage. In that case, Fritzlein's dog could capture Omar's c4 rabbit and then create further threats in the west. For Omar, holding the camel hostage might not be worth having his elephant in the southeastern corner. The strength of a hostage further depends on what the defending elephant can do; a hostage defender might leave at any time in pursuit of some other prize. Usually that other prize is a horse at best, i.e. something worth less than the camel which would be lost. In an endgame, however, a camel can be abandoned in pursuit of a goal, which is obviously worth more.
  • 60g: Omar declines to take the hostage, and instead moves his elephant west. Fritzlein's rabbit advance to e4 costs Omar a step here.
  • 60s to end: Fritzlein's win is now a matter of patience and technique. He has time to calculate variations exactly to be sure that Omar cannot outrace him to goal. At this point, Omar can only defend and hope for a mistake.

    On 62g, Omar stops an immediate goal by surrounding Fritzlein's camel. On 63g, Omar does not have time for a dog capture, as he must ensure that he can occupy f1 even if the rabbit is pushed up. On 64g, Omar's elephant is forced to its home rank to get the cat onto f1. Fritzlein then threatens goal in the west, and Omar decides to go down shooting.


Each player missed opportunities for strong trap attacks, perhaps because of where Arimaa strategy was in 2005. By later estimations, Fritzlein held a continuous advantage after 21g, though he would have been walking a tight rope had Omar better pressed him after 39s.