Difference between revisions of "Cornering"

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(Added another cornering move.)
(D3 corner move: Showed a more logical sequence of moves for d3 corner move.)
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Revision as of 03:21, 28 June 2021

In a ladder situation when no ladder escape exists, the attacking player can ladder into a corner and create a "quasi-escape piece" at the very last minute. This play is called cornering.

Pivoting

The most common form of cornering is pivoting: when the attacker breaks the ladder by playing one hex ahead. This usually results in a ladder for the opponent. Example:

13524

This results in a new ladder, but now the attacking player is defending instead.

9876

Red could have also cornered earlier, resulting, for example, in a 4th row ladder for Blue.

C4 corner move

Given enough space, the attacker can sometimes get an outcome that is better than merely turning the ladder, though not as good as a switchback. For example, starting from a 2nd row ladder, the following maneuver lets Red move towards the center, rather than parallel to Blue's edge:

51324

Blue now has several options, but all of them allow Red to connect towards the center of the board:

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Note how Red's 9 is connected to the edge via a double threat at the cells marked "*". If Blue instead plays 6 on the second row, things are generally worse for Blue:

9876

Note that Red's 7 is connected to the edge via edge template IV2b.

D3 corner move

Another useful corner move for second row ladders is this:

51324

This allows the attacker to climb to "*", even without a switchback threat, as follows:

17121115139161410768

This move has some similarities with Tom's move, although it does not require a parallel ladder. Note that 5 and 9 are connected to the edge by edge template IV2b. The shaded area is not required for this move, i.e., it can be occupied by Blue.