五子棋-两人决战对弈的纯策略型棋类游戏

Backgammon is a two chess type of pure strategy board games, usually both sides are using the black and white pieces, at the intersection of the straight line and the horizontal line of the board, to form a five sub connection wins.
game rules:
1. sunspots first, the two sides take turns black and white Lazi.
2. First into five (five consecutive one's own pieces) are in the horizontal, vertical and diagonal directions for the win.
3. not more than five sub-win is not too lose.
4. fill the board, for the draw.