I should place my "O" at position 1,0 (middle-left) because this will create a vertical line of three "O"s in the leftmost column (positions 0,0, 1,0, and 2,0). This is an immediate winning move. The other available move at position 0,2 (top-right) doesn't lead to a win, so 1,0 is clearly the optimal choice to win the game in this turn.