When you have to guess
When nothing can be proven, open the cell least likely to be a mine.
In the classic game a board can leave you with no safe move: every hidden cell could be a mine. Then count the ways the mines can lie that fit all the numbers and the counter, and open the cell that has a mine in the fewest of them. Two cells with one mine and nothing else to tell them apart are a true 50/50. This site builds every board so that it can be solved without guessing, and tells you on the rare board where it could not; in other games you will need this.
How it works
No number here proves any cell, not even with the mine counter: every hidden cell could be a mine.
Your turn
Each board is a real position from a game. Tap or click to open; right-click, long-press or switch on Flag to place a flag. If you are not sure, take a hint: the first one only shows where to look.
Which cell is least likely to be a mine?
How the exercises were chosen
A computer checked every board: in what you see, nothing can be proven, even with the counter. The chances count every layout of mines that fits the numbers and the counter.