Two good tic-tac-toe players started a game, but the wind blew away their paper just after the second play. Given that the situation was as follows, who was to play next, O or X?
| |
---+---+---
O | |
---+---+---
X | |
If X had played the opposite corner, what would you say?
It is clear that if X moved first that the subsequent O move was a losing move. X's subsequent move would be to the lower right corner, creating the threat of a row across the bottom. O must move in the center box in the lowest row to block. Then X moves to the upper right hand corner, creating two possible wins on X's next turn. Since O can only block 1, X would win.
However, the problem states that both are experienced players. Therefore, the first player would never place a mark in a square that was not a corner or center square. O must move first and can avoid losing the game.
GS