Puzzle 38 | (Tic Tac Toe Puzzle)

Statement: The game of Tic-Tac-Toe is being played between two players, and the board is in the following state after six moves.

Can you answer the following questions?

1. Who will win the game — O or X?
2. What was the sixth move, and at which position was it made?

• Assume that both players are equally intelligent and that every move they make is the best possible choice for that situation.
• Additionally, it is not known which player — X or O — made the first move.

Check if you were right - full answer with solution below.

The key is to work backward from the final board state and determine the only sequence of intelligent moves that leads to it.

The following problem shows two possible scenarios,

If it is O’s turn next, O will win.

If it is X’s turn next, X will win.

After considering both scenarios, the seventh move will be the decisive one. Therefore, our main goal is to determine what the sixth move was and who made it.

Before analyzing the seventh move, we need to identify the sixth move. There are two possible options for the sixth move:

1. If O is placed in the seventh position, the move is intended to block X from forming a straight line and winning the game. However, this is unnecessary because O could have won the game on the sixth move by placing O at position 5.
2. X made the sixth move at position 9. Even if X had chosen a different position for the sixth move, the outcome would have been the same — O would inevitably win, since no matter where X is placed, O can still win the game.