Tic Tac Toe Tactics

Logic

Assume that you are playing a tic-tac-toe game with an opponent. You play as $X$ while your opponent plays as $O$ .

The game is played as follows:

Find all the possible grid tiles where you can put an $X$ -mark that will help you guarantee a win under best play.

a

b

c

d

e

Either

a

b

Either

b

e