I'm coming up with the same as you. You have to make your 9th move sub board match the greater board location, so in this case NW board and NW corner. Now wherever they move will send you to a different board, where you can make the move there to the NW corner, and they are forced back to the NW board. Repeat until you have two in a row on most of the boards and you should be able to make the win.