Go-Moku is played on the 19*19 go-board. The object of this board game is to get five stones in a row, be it horizontal, vertical or diagonal. You have noticed that six in a row do not win, such a construction is called an overline. In that case, the game just goes on till you achieve your goal. Of course, the game can end in a draw, if the players agree or the whole board is full of stones while no player has five stones in a row on the board.
You can refer the following link for the strategies that AI has to solve the game: