Difference between revisions of "Opening"

Latest revision as of 18:04, 19 March 2023

The opening of a game of Hex is the initial sequence of moves that occur at the start of the game. The specific number of moves considered as part of the opening can vary depending on the type of opening and the perspectives of the players. However, typically the first two moves of the game are considered part of the opening.

Opening theory

Opening theory is the study of the strategies and techniques used in the opening of Hex. Two of the most fundamental questions in opening theory are:

• Where should the first move be played?
• Should the players swap positions?

The first move

The decision of where to play the first move is particularly important for the first player. It should not be too strong, as the second player will then swap, but also not too weak, as the second player will decline the swap and have a better position. Therefore, the first player must find a move that gives both players an approximately equal chance of success.

There are certain moves that are considered fair, such as a2, a3, b2, and c2, which are common opening moves. However, these are only suggestions, and many other moves may be tried, such as a4 to a8, a11, and c10 (on an 11×11 board).

Swapping

When considering whether to swap, one rule of thumb is to swap any opening, except if the first move was played on the first row, adjacent to a friendly edge, and not in the obtuse corner. Players can also look at winning opening moves for small boards.

Opening theory for specific board sizes

There are specific articles for openings on different board sizes:

• 11 x 11
• 13 x 13 (adapted from Jonatan Rydh's page on openings)
• 19 x 19

Specific opening moves

Some opening moves have their own dedicated articles.

• A2 opening
• A3 opening
• B2 opening
• Center opening
• A1 opening
• Obtuse corner opening
• The Hungarian (opening)