Super Tic-Tac-Toe

Goal: Capture 3 sub-grids horizontally, vertically, or diagonally.

To catch a sub-grid, you must capture 3 boxes horizontally, vertically, or diagonally inside of the sub-grid.

However, upon capturing a box, the other player is restricted to capturing a box inside of the sub-grid (relative to the entire board) corresponding to the box (relative to its sub-grid) that you captured.