Notes on this puzzle
40 mines, 216 safe cells and one 16×16 field: that is Mine Finder #5201. Some cells only give way when two neighbouring numbers are compared.
The board starts with 85 cells already uncovered, 39% of the safe ground, so the first deduction is waiting for you. Under the cover, 54 safe cells touch no mine at all, 88 show a 1 and 62 show a 2; 12 cells carry 3 or more, and the highest number in the field is 5. 9 of the mines lie along the border of the field.
Where to beginWhen two numbers share most of their neighbours, subtract one from the other.