Page "Dots and Boxes" Paragraph 4

The diagram on the right shows a game being played on the 2 × 2 board.

The second player ( B ) plays the mirror image of the first player's move, hoping to divide the board into two pieces and tie the game.

The first player ( A ) makes a sacrifice at move 7 ; B accepts the sacrifice, getting one box.

However, B must now add another line, and connects the center dot to the center-right dot, causing the remaining boxes to be joined together in a chain as shown at the end of move 8.

With A's next move, A gets them all, winning 3 – 1.