Arimaa/Attacking/Positioning

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For simplicity, many examples will assume that Gold is attacking the c6 trap. Naturally, the same principles apply when Gold attacks f6, or when Silver attacks c3 or f3.

Positioning the elephant[edit]

While attacking the c6 trap, the gold elephant would most often want to occupy d6. An attacking elephant would usually be quite limited on b6 or c7, where it might even get blockaded. In most cases, an attacking elephant would rather be on d6 than on c5:

  • If Silver still owns f6, the gold elephant is the only gold piece which can safely stand in between c6 and f6; any other gold piece on d6 could be quickly forked.
  • Blocking Silver out of d6 could later compel her to occupy c5, which is not ideal for a trap defender. Any non-elephant silver piece on c5 could be pushed or pulled to c4, and Gold might have threats in both c3 and c6. To avoid this, the silver elephant might defend its own home trap, but then Gold would have a space advantage.
  • A d6 gold elephant protects a c7 gold piece from being pulled into the center and forked between traps.
  • A d6 gold elephant blocks silver defenders arriving from the east.
  • A d6 gold elephant impedes the forward development of silver pieces from their back ranks.
  • A d6 gold elephant can easily move to e6 to defend or attack the f6 trap.

However, c5 is an acceptable square for the attacking gold elephant, and may be better if, for instance, there is an important fight happening around c3.

Once the gold elephant occupies d6, it should stay there until there is a good reason to leave. A chance to make simultaneous threats in c6 and c3 probably justifies moving the gold elephant from d6 to c5, unless that would allow Silver to pull out an advanced gold piece and fork it between c6 and f6.


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6 Arimaa rs.svg Arimaa hg.svg Arimaa eg.svg Arimaa ms.svg 6
5 Arimaa ds.svg Arimaa rs.svg Arimaa rs.svg 5
4 Arimaa cg.svg Arimaa rg.svg Arimaa es.svg Arimaa rg.svg 4
3 Arimaa hg.svg Arimaa dg.svg Arimaa hs.svg 3
2 Arimaa rg.svg Arimaa dg.svg Arimaa cg.svg Arimaa mg.svg 2
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Diagram 1: Silver to move can do little to counter Gold's attack.

Diagram 1 shows an ideal attack; Gold has taken firm control of the c6 trap. Notice these positional features:

  • The silver elephant would need two turns to reach c5.
  • Far away from both gold horses, the silver camel is poorly positioned.
  • The a5 dog is the only silver piece that could immediately reach c5 (with da5e ra8s ra6s db5e) and thus become a second silver defender of c6. However, the gold horse could then push the dog to c4, creating capture threats in both c3 and c6 while the gold elephant remained on d6.
  • Silver cannot scatter in time to prevent a c6 capture; even if Silver could do so, Gold could then advance a rabbit on the c-file, threatening goal.
  • If the gold elephant were on c5 rather than d6, Silver to move could temporarily defend the trap with two steps such as he7sw, and still bring her elephant toward the northwest quadrant with Rf4s eg4w.

Silver to move cannot occupy b6 or d6, and cannot safely occupy c5. With the four strongest silver pieces all in the east, Silver is very weak in the west. Gold beats Silver in alignment, balance, and centralization.

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7 Arimaa ds.svg Arimaa hg.svg Arimaa cs.svg Arimaa rs.svg 7
6 Arimaa cs.svg Arimaa ds.svg 6
5 Arimaa hs.svg Arimaa rs.svg Arimaa eg.svg Arimaa es.svg 5
4 Arimaa hg.svg 4
3 Arimaa rg.svg Arimaa dg.svg Arimaa dg.svg Arimaa rg.svg Arimaa hs.svg 3
2 Arimaa rg.svg Arimaa cg.svg Arimaa mg.svg Arimaa cg.svg Arimaa ms.svg Arimaa rg.svg 2
1 Arimaa rg.svg Arimaa rg.svg Arimaa rg.svg Arimaa rg.svg 1
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Diagram 2: The gold elephant has failed to secure d6.

By contrast, Gold is very weak in diagram 2 with Silver to move. Silver can play ed5nns Hc7e, freezing the gold horse and preparing to fork it between c6 and f6 (a horse-by-elephant hostage is usually a bad long-term strategy, but this is a direct capture threat that can't easily be defended against). This is a risk of having an attacking piece on c7 without the attacking elephant on d6. As an aside, Silver should make this move immediately; otherwise, Gold could move his c7 horse west and still have time to defend against Silver's eastern attack.

Although an attacking elephant should generally not be decentralized, there are exceptions. If the silver camel is on a6 or b6, the gold elephant might step onto that square to push the camel south, sending Silver scrambling to prevent a strong camel hostage in the southwest. Also, if Gold has a strong goal threat, it may be worthwhile for the gold elephant to move onto the 7th or 8th rank. This should only be done with great caution, however, as an elephant can easily become blockaded in a corner. When possible, a different piece should be used to support a flank rabbit advance.

Key squares[edit]

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7 Arimaa rs.svg Arimaa ds.svg Arimaa cs.svg Arimaa rs.svg 7
6 Arimaa rs.svg Arimaa cs.svg Arimaa rg.svg Arimaa eg.svg Arimaa ms.svg Arimaa hs.svg Arimaa rs.svg 6
5 Arimaa rs.svg Arimaa rg.svg 5
4 Arimaa cg.svg Arimaa hs.svg Arimaa es.svg 4
3 Arimaa rg.svg Arimaa dg.svg Arimaa mg.svg Arimaa dg.svg Arimaa hg.svg 3
2 Arimaa rg.svg Arimaa hg.svg Arimaa cg.svg 2
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Diagram 3: Gold cannot gain access to b6 or c7. (Game)

A successful opening attack usually requires one's horse or camel to occupy b6 or c7. In diagram 3, Gold attacked in the west, but Silver kept the decentralized key squares, which Gold is now blocked from. If the gold elephant leaves the trap, Gold will lose material; Silver can now overload Gold, whose western attack backfired because he did not take b6 or c7. Generally speaking, rabbit advances must be connected to the activity of strong pieces other than the elephant.

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6 Arimaa hs.svg Arimaa hg.svg Arimaa cs.svg Arimaa eg.svg
5 Arimaa rg.svg Arimaa es.svg
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Whether an attacker is better on b6 or c7 depends on the position:

  • A gold attacker on b6 is freer to retreat if it becomes necessary to abandon the attack.
  • A gold horse on b6 may be harder for the silver camel to take as a strong hostage (a strong horse-by-camel hostage does not depend on the hostage-holder's elephant to stay nearby).
  • A gold horse on b6 denies the silver horse its ideal defensive square. In the diagram at left, the a6 silver horse is passive.
  • A gold attacker on b6 restricts the development of silver pieces in the west, securing a space advantage for Gold.

On the other hand:

  • With a gold attacker on c7, Gold has a real chance to get an additional attacker onto b6. The reverse, getting an attacker onto b6 and then another onto c7, is less likely; with an attacker on b6 and the trap still contested, an additional attacker's path to c7 will normally be blocked.
  • A strong gold piece on c7 blocks silver reinforcements coming from the east.
  • It is usually easier for an attacker to temporarily leave c7, allowing Gold to move his elephant while retaining long-term shared control of c6. At left, the gold horse cannot move and then hope to return to b6. Were the gold horse on c7, it might be able to step away and return later.

If an initial Gold attack is successful, c7 may gain importance, as it will help determine what Gold has room to do. If Gold can keep silver pieces off of c7 and c8, he may soon have a strong goal threat. If possible, a b6 attacker should consider moving to c7.

Once the attacker has firm control over key squares, captures will soon be possible, unless the enemy elephant defends. In that case, the attacker might swarm the trap, perhaps creating a blockade or goal threat that will further restrict the defending elephant and possibly free the attacking elephant.

Positioning a rabbit[edit]

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6 Arimaa hg.svg Arimaa hs.svg Arimaa hs.svg 6
5 Arimaa rg.svg Arimaa hg.svg 5
4 Arimaa rs.svg 4
3 Arimaa dg.svg Arimaa es.svg Arimaa eg.svg 3
2 Arimaa cg.svg Arimaa dg.svg Arimaa cg.svg Arimaa ms.svg Arimaa rg.svg 2
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Diagram 4: Silver to move could push the gold rabbit onto c6, delaying any capture by Gold.

Until there is a chance for a strong goal threat, the flanks may be the best places for advanced rabbits; a friendly rabbit next to a trap can be a liability for an attacker trying to capture material. In diagram 4, it might appear that Silver to move cannot prevent a loss in c6. However, Silver has one "nuisance move" that will delay a capture: hd6s Rc5n hd5we. That would leave the gold rabbit on c6 and the silver horse on d5, precluding any one-turn capture by Gold. On d5, the silver horse would be less vulnerable than it might seem: if the gold camel went to d6, Silver would have a chance for a camel trade. If the gold camel went to c5, Silver could then place defenders on both c7 and d6. If left alone, the silver horse might go south and start something. If not for the c-file advanced gold rabbit, things would have gone much more smoothly for Gold. Gold still has a strong position as long as he is careful with his camel, but this shows how one misplaced rabbit can be exploited by the opponent. If both sides were actively attacking, such a delaying tactic could prove decisive. Since a rabbit can neither retreat nor push any piece, rabbits must be positioned very carefully in an attack.