Arimaa/Race Positions
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gold has just captured a silver dog in f6, and several more captures could quickly follow. |
A race position occurs when both sides can make quick progress in different parts of the board. A race will slow or stop when one side chooses defense over offense. If too many captures occur, however, there will be few pieces left to use for defense. It is thus important to avoid or quickly exit a race that one cannot ultimately win.
In this game, each side left a home trap vulnerable. Silver got a strong attack on c3, but lost a dog in f6. On 5s, Silver had to decide whether to capture the c2 horse or use two steps to preserve his own camel in the northeast. Silver chose the former, using his fourth step to prevent a flip-capture and thus ensure that the camel loss would not be immediately followed by another loss. Gold correctly captured the silver camel in f6, but then continued to race, neglecting defense until it was too late. Silver's multi-piece attack opened a goal path which Gold could not outpace. After capturing the silver camel, however, Gold could have moved his elephant west to defend c3, exiting the race with enough pieces left to delay a silver goal. If the elephants then remained deadlocked at c3, Gold would have been strong in the east.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
This is no longer a capture race, as advanced rabbits threaten goal. |
A capture race may quickly turn into a goal race, due to the space cleared. 37g and 38g of this game forced Silver to defend goal rather than continue a cleanup which might have soon resulted in a silver goal. On 38s, Silver had to stop the d6 rabbit; merely freezing it in place would not be enough, as Gold could unfreeze and unblock it with Dc7s rd7w, leaving two steps for goal. If Silver used his elephant to stop this goal, his own threats in the east would be gone. 38s mg6ww Rd6s me6w would preserve Silver's eastern threats, delay Gold's threats, and even threaten the c7 dog. Alternatively, 38s cf7w rg8w ee4s Mf4w would stop a one-turn goal and threaten the gold horse, which is needed to defend goal. Even if Gold were to then capture the b6 horse and step the d6 rabbit west, Silver could block the goal with his western dog and continue to press his eastern threats, perhaps capturing the gold camel or horse. The played 38s stopped the gold goal, but allowed Gold to pull even in material and create a new goal threat. To win a race, one must have a strong response to anything the opponent might do.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Silver's potential goal threats restrict the gold elephant, and Gold's advanced pieces are at risk. |
A race typically involves two active elephants. If one elephant is stuck, even temporarily, any race is likely to favor the opponent. In this game, a race began while the gold elephant defended goal. Gold captured both silver horses, but did not have time to capture the advanced silver rabbits. Silver allowed her camel to be captured on 30g, as her eastern goal was then unstoppable.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gold to move could create a strong western goal threat. Silver to move can block the b1 rabbit or push it onto c1. |
In this game, a capture race put Gold behind in material, but a b-file rabbit advance turned things around. Silver raced too quickly; rather than capturing a passive rabbit on 16s, Silver could have blocked the b-file rabbit or pushed it to c1.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gold can outrace a western cleanup if he captures the f7 cat and then advances the f2 rabbit on the next turn. |
In this game, Gold quickly moved his elephant to the h-file, initially going after the silver camel but then allowing the camel to go west while he threatened a dog. Even in the face of an elephant-camel attack, Gold made no attempt to defend c3. Opting to race, Gold initially traded a rabbit for a cat. Silver had time to move her horse away from f6, and appeared poised to clean up in c3. Instead of capturing a rabbit or dog on 9g, Gold advanced a rabbit and threatened goal; this threat was strong, due to Silver's imbalance. Silver did capture a horse, but was then forced to abandon the southwestern cleanup and move her elephant to the northeast. Gold's early goal threat did not directly win the race, but slowed it down enough for Gold to create strong threats on both wings.
In essence, a race occurs whenever each respective elephant leads an attack on an away trap. Even before any piece is captured, the outcome of an all-out race might be foreseeable. One can decline or exit such a race by bringing the friendly elephant home to defend; a slow counterattack may then be feasible.
While early rabbit advances require caution, a goal threat could decide a race even before captures begin, as one side might soon have to defend goal rather than keep pace with captures.