Show HN: Shifting Tic Tac Toe

Hey Phil, you stole my idea<g>!

I called mine "dynamic" tic tac toe and it features human play against an "AI" algorithm with the human graciously afforded the first move.

After the 6th move, the oldest move disappears from the board.

Suggestion: For even more fun, start erasing the oldest square after the 5th or 6th move. Which one applies is chosen at random at the start of each new game.

If erasing starts after 5 moves, the game is unwinnable with perfect play. Basically, this is a never ending draw until a mistake is made. And against a perfect "AI" algorithm, the human side can only lose.

If erasing starts after 6 moves, the human side (first player) always wins with perfect play.

The proof of this is left as an exercise for the developer.

This above assumes the computer side plays "fair" and doesn't know/account for the oldest square until after it has been erased. And just between you and me, the "AI" part is just BS --- this simple game is logically solvable and can be easily built with standard programming techniques.