TicTacToe9*9

TicTacToe9*9 takes the classic game of Tic-Tac-Toe and adds a strategic layer to it.
Tic-tac-toe is terminally dull. There’s no room for creativity or insight. Good players always tie.

1.Each turn, you mark one of the small squares.
2.When you get three in a row on a small board, you’ve won that board.
3.To win the game, you need to win three small boards in a row.
4.You don’t get to pick which of the nine boards to play on. That’s determined by your opponent’s previous move. Whichever square he picks, that’s the board you must play in next.

What if my opponent sends me to a board that’s already been won? In that case, congratulations – you get to go anywhere you like, on any of the other boards. (This means you should avoid sending your opponent to an already-won board!)

Credits to this link : http://mathwithbaddrawings.com/2013/06/16/ultimate-tic-tac-toe/