Advanced Minesweeper: reduction, mine counting and better guesses
Once you recognise the 1-1 and the 1-2-1, the next step is reasoning with overlapping numbers, using the mine counter in the endgame and, when there’s no other way, guessing with judgement. It’s what separates finishing the Hard board from getting stuck halfway.
· 3 min read
Play Minesweeper1. Reduce: subtract what you already know
A number counts the mines around it, but if some of those mines are already flagged, what matters is how many are left. A 3 with two flags beside it behaves like a 1 for the rest of its covered cells. Thinking this way, “reducing” each number, makes patterns appear where there seemed to be none.
The basic patterns work the same with reduced numbers: a 4 with two flags next to a 3 with two flags can, in practice, be a 2-1 you already know how to solve.
2. Compare neighbouring numbers
When two numbers share covered cells, compare which cells each one touches. If a 1 touches cells A and B, and a 2 next to it touches A, B and C, the 1’s mine is in A or B, so the 2’s second mine must be in C.
The general rule: if all of one number’s cells are included in another’s, the difference between their values is the number of mines in the cells only the second one touches. If the difference is zero, those cells are safe; if it equals the number of those cells, they are all mines.
3. Use the mine counter in the endgame
The counter shows the mines left according to the flags you placed. In the endgame it’s one more clue: if two covered cells are left in an unsolved area and the counter says 1, you know there is exactly one mine between them, and that can solve the rest of the board.
For the counter to help, your flags have to be right. Only flag when you’re sure; a wrong flag doesn’t just make you open a mine when chording, it also makes the counter lie.
4. When you have to guess, choose well
Sometimes no deduction is left. Before clicking at random, compare the risks. A cell next to a 1 that touches eight covered cells has a 1 in 8 chance of being a mine; a cell next to a 1 that touches only two, 1 in 2.
The overall density helps too: Hard has 99 mines in 480 cells, roughly one in five. A cell far from every number carries about that risk, and when it’s safe it often opens new information. Between two similar guesses, pick the one that solves more if it works out.
5. Saving time on Hard
To bring your times down, chord on numbers instead of uncovering cell by cell, and don’t place flags you don’t need for chording: the game is won by uncovering every safe cell, not by flagging every mine.
Work by areas: finish one edge before jumping to another, so you don’t have to read the same numbers twice. And if the board is too wide for your screen, on a phone Hard turns vertical so the cells stay large.