Minesweeper first click and guessing

Minesweeper is mostly skill with a little luck. Your first click can't hit a mine, and most of the board can be solved by pure logic from the numbers. But classic Minesweeper places mines at random, so some boards contain spots where the numbers genuinely can't tell you which square is safe, and you have to guess. Good players still win more because they guess less often, and when they must, they pick the square with the best odds. Try the ideas below in the free Minesweeper game.

Why the first click is safe

When you start a game, no mines have been placed yet. They're laid down only after your first click, at random, but never on the square you clicked or any of its eight neighbours. So your first square always has a zero, and the game opens a whole area around it, giving you numbers to work with straight away.

The classic Windows game had a simpler version of this safety net: it's widely reported that if your first click landed on a mine, that mine was moved elsewhere. That saved you from losing on move one, but your first square could still show a number, leaving you nothing to reason from. Clearing the whole 3 × 3 block, as our game does, means you always start with an open area.

How dense are the mines?

The level decides how crowded the board is:

Level	Grid	Mines	Mine density	Density outside your first 3 × 3
Beginner	9 × 9	10	12.3%	13.9%
Intermediate	16 × 16	40	15.6%	16.2%
Expert	30 × 16	99	20.6%	21.0%

That last column is roughly the chance that a random covered square you know nothing about is a mine, early in the game. On Expert it's about one in five. As the game goes on, the true figure is simply the mines still hidden divided by the covered squares you have no information about.

When guessing is forced

Usually, if you think you're stuck, you've missed a deduction. Look at pairs of numbers together first; the Minesweeper patterns guide shows the common ones.

Sometimes, though, the board really doesn't decide. The classic example is a 50/50: two covered squares, exactly one mine between them, and no other number touches either square. Typical places:

• Two squares at the edge of the board, side by side, with a 1 next to both and nothing else around them.
• Two covered squares at the end of a row of numbers, where every number that touches one also touches the other, and they say there's exactly one mine between them.

No amount of thinking helps here. Each square is equally likely to be the mine. Our game, like the original, doesn't check boards for guess-free solutions, so these do turn up, especially on Expert, where mines are packed tightly.

Как это сделать make the best guess

When you must guess, a few rules improve your odds.

1. Compare local odds with the background odds

A number tells you about the squares around it. A 1 touching three covered squares, with nothing else known, puts the mine in one of three places: roughly 33% each. A random covered square far from any number carries only the background density: about 14% to 21% depending on the level. So a square in an unexplored part of the board is often safer than one next to a 1. Work out both before you click.

2. Prefer squares that can open up the board

A guess that reveals one number is often followed by another guess. A likely zero opens an area and gives you lots of new information. Corners have only three neighbours, so they're far more likely to be blank. For a safe square in untouched territory, we calculated (with node, counting the mines spread over the squares outside your first 3 × 3) these rough chances that it turns out to be a blank:

Level	Corner	Edge	Middle
Beginner	about 63%	about 46%	about 28%
Intermediate	about 59%	about 41%	about 24%
Expert	about 49%	about 31%	about 15%

So when a guess in fresh territory is the best option, a corner gives you the best chance of a big opening.

3. Guess early, not late

If a 50/50 is unavoidable, it doesn't get better with time. Taking it early means that if you lose, you lose a 30-second game rather than a five-minute one. The exception: if solving another part of the board could reveal a number next to the 50/50, do that first, because it might settle it.

4. Pick the guess that teaches you the most

When two squares have the same odds, choose the one whose number would resolve other uncertain squares. A guess that settles a whole edge is worth more than one that settles nothing.

So, is Minesweeper luck?

On any single board, luck plays a part: a forced 50/50 can end a well-played game. Across many games, skill dominates. Better players:

• spot deductions that weaker players miss, so they guess far less often,
• choose better squares when they do guess,
• and play faster with chording, which matters for best times.

Practise reading the board

1. Open the free Minesweeper game on Beginner. Your first click opens an area.
2. Before every click away from the open area, ask: "Is this a deduction or a guess?"
3. When it's a guess, estimate the odds as above and choose the safest square.
4. Move to Intermediate and Expert as your logic gets quicker. Best times are saved for each level in your browser.

New to the controls? How to play Minesweeper covers flags, chording and playing on a phone. For a game where memory matters more than odds, try the free memory game.

Test your odds

Pick a level and see how far logic takes you before you need a guess. The free Minesweeper game runs in your browser with no sign-up.