Arimaa/Introduction to Strategy/Race Positions

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37px-Arimaa board.jpg
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a8 b8 c8 d8 e8 f8 g8 h8
a7 b7 c7 d7 e7 f7 g7 h7
a6 b6 c6 d6 e6 f6 g6 h6
a5 b5 c5 d5 e5 f5 g5 h5
a4 b4 c4 d4 e4 f4 g4 h4
a3 b3 c3 d3 e3 f3 g3 h3
a2 b2 c2 d2 e2 f2 g2 h2
a1 b1 c1 d1 e1 f1 g1 h1
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The players are racing to capture pieces as quickly as possible.


Race positions occur when the two elephants each take control of an opposing trap, as in this game diagrammed at right. In a race position, both elephants are clearly free, so elephant mobility is of secondary importance. The critical issue is which elephant can do more damage more quickly.

A player who would lose a race should avoid or abandon it. Silver to move is winning this race because of her still full home rank, as well as the b3 horse which strengthens Silver's control of c3. An elephant by itself is quite limited; Gold to move could capture the silver camel in f6, but that would use all four steps and still leave the gold elephant decentralized. Instead of saving her camel, Silver to move can capture the c2 horse in three steps and advance the a6 rabbit to a5. If Gold does then capture the camel, Silver can continue the race by capturing the b2 dog. Thus far, Gold has not necessarily erred, but he must now move his elephant toward c3 rather than make another capture in f6. Gold might think he has a strong eastern goal threat, but if he pulled down the f8 rabbit, the e8 and d8 cats could each take one step east, leaving Silver plenty of time to get the now a5 rabbit to goal.

37px-Arimaa board.jpg
Arimaa-border.png
a8 b8 c8 d8 e8 f8 g8 h8
a7 b7 c7 d7 e7 f7 g7 h7
a6 b6 c6 d6 e6 f6 g6 h6
a5 b5 c5 d5 e5 f5 g5 h5
a4 b4 c4 d4 e4 f4 g4 h4
a3 b3 c3 d3 e3 f3 g3 h3
a2 b2 c2 d2 e2 f2 g2 h2
a1 b1 c1 d1 e1 f1 g1 h1
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Arimaa-border.png
Goal threats trump capture threats.

In the position at left, from this game in the 2006 Arimaa World Championship, Silver is on move. Each player is threatening goal. As soon as one player is forced to defend with his elephant, his own goal threat won't be viable, and friendly pieces will be left vulnerable to capture. Very likely, whoever loses this race will lose the game.

Silver would like to push the f4 camel to f5 and then move the g3 rabbit to e3, threatening captures and goal. Instead, he must stop the d6 rabbit; merely freezing it would not be enough, since the c7 dog could step to c6 and pull the d7 rabbit to c7, unfreezing and unblocking the d6 rabbit, which could then step to goal. Silver's best option may be for his camel to push the d6 rabbit back to d5; besides setting back the goal threat, this would contest control of c6, where the b6 horse is threatened with capture. To retain control of c6, the gold elephant would likely step to c5; if Gold used his other three steps to capture the g3 rabbit, the silver elephant could then capture the gold camel in f6, and could likely then stop Gold's northwestern threats. Silver would then be poised for a new, stronger attack in the east. If Gold foresees this, he will likely choose not to immediately end Silver's current goal threat, and instead reestablish full control of c6 by pushing the silver camel off of d6. Gold would have capture threats, but not yet a one-turn goal threat, and the race would continue.

When one loses home trap control, it is probably too late to start a race. Instead, the defender might protect material with the elephant while building towards a slower counter-attack.

Elephant Blockade