File:GuessingOpen.png

It is not possible to solve mine locations, but you can prove the blue squares are empty. If the blue squares are a 1, you can then open the orange squares. The original guess might be eliminated by opening these squares.

NOTE: Originally this picture showed the walls of a Beginner board, but Thomas Kolar noted 27 Aug 2011 that in this particular example of only 8 squares in a row you can not eliminate the guessing: all patterns opened with this technique will reduce to a row of 1's above the original row, and you will still be forced to make one 50/50 guess to win the game. I cropped the picture to remove the walls, so the example clearly works if you consider the picture to be part of a larger grid.