glossary.title

Two of your stones connected in a line with both ends open, still able to grow in either direction. It is the seed of an attack: harmless alone, but if left unchecked it develops into an open three and then a four.

In the opening, do not only build your own twos — watch the opponent’s two central open twos, the usual birthplace of initiative.

Three of your stones in a line where one more stone creates a live four (an unstoppable win). The open three is the real engine of the game: once it appears, the opponent is usually forced onto the defensive.

When the opponent plays an open three, block the end that extends toward a live four; when both ends threaten, answer the stronger side first.

Three stones in a line where only one end remains open (the other is blocked). It cannot become a live four, but it can turn into a forcing four — still a reliable attacking tool.

The sleeping-three-plus-four combination (the four-three finish) is the most common forced win: the three carries the attack while the four compels a response, covering each other.

A single move that creates two open threes at once. The opponent can block only one, and the other is guaranteed to become a live four — making it nearly unstoppable under freestyle rules.

Under freestyle rules black can use double threes too — one reason YiBoard plays freestyle: simpler rules, freer attacks.

Four stones in a line that will become five on the next move. It forces the opponent to block immediately, handing you the initiative — they have no choice but to follow your tempo.

Chained forcing fours buy you time and initiative — if you count the plies, you can complete five before the opponent can counter.

A move that creates both a forcing four and an open three. The opponent must answer the four, freeing your three to become a live four — the most common winning combination in gomoku.

Before playing a four-three, confirm the far end of the open three is not already blocked — otherwise the advantage silently slips away.

Four stones with both ends open. Whichever end the opponent blocks, you complete five at the other — it means the game is effectively won unless the opponent wins first.

The only defense against a live four is stopping it before it forms — once it lands, there is usually no recovery.

A line of more than five stones (six or more). Under freestyle rules any line of five or more wins, so overlines are legal; under forbidden-move rules black is barred from overlines.

YiBoard is freestyle: five or more in a row wins, no forbidden moves to remember, rules in one sentence.

A competitive rule that balances black’s opening advantage: black is forbidden from making double threes, double fours, or overlines. Violating is a loss. YiBoard does not enforce forbidden moves, keeping rules close to the casual “freestyle five” players already know.

If you practiced with forbidden moves elsewhere, loosen up on YiBoard — double threes and double fours are all legal here.

The exact center intersection of the board (H8 on a 15×15 grid). Holding the center pressures all four directions at once and is the most common opening move for black.

Open at the center star point, then build tightly around the opponent’s shape — the most solid opening strategy for beginners.

The state of holding the offensive: you keep forcing replies with fours and open threes, so the opponent spends every turn blocking and never finds time to build their own attack.

To judge a game, do not count stones — see who keeps posing the questions. Whoever sustains the initiative is almost always ahead.