Related Clues:

• Tic-tac-toe line ... and a hint to this puzzle's theme
• Hockey shutout box score
• Hockey shutout line score
• Meter setting
• Thousands symbol
• Winning line in tic-tac-toe
• None, nada, nothing
• Queenside castling notation
• Zilch zero zip
• XXX's opposite
• Love letter symbols
• Tic-tac-toe row
• Win in a simple game
• Pedometer's starting point
• Reading after resetting