There are three difficulty levels for Minesweeper: beginner, intermediate, and expert. Beginner has a total of ten mines and the board size is either 8 8, 9 9, or 10 10.

We have 492556=125244 ways for an easy grid to have an 8 somewhere. Out of the 1.88 trillion total easy grids, this gives a probability of about 610"8. So, very rare indeed!