Minesweeper Glossary: 3BV, Chording and Terms Explained
This glossary explains the words used in Minesweeper guides, rankings and tools. Each definition states what the term measures or changes, then links to a page where you can see it in practice. Start with chording and patterns if you are learning; use 3BV/s and efficiency when comparing speed.
Rules, patterns and performance terms
3BV - Also called Bechtel's Board Benchmark Value
- 3BV estimates the minimum number of left-click actions needed to solve a particular board without chording. Each opening counts once, and every remaining safe cell not revealed by an opening counts once. A higher 3BV board contains more measured clearing work, even when its width, height and mine count match another board.
3BV/s - Also called 3BV per second
- 3BV/s divides a board's 3BV by the solve time. It measures how quickly a player completed the board's required work, so it compares runs more fairly than seconds alone. A fast time on an unusually easy board can still have a modest 3BV/s.
Cascade - Also called Opening
- A cascade is the group of cells that opens automatically when a zero cell is revealed. The game keeps opening connected zeroes and their numbered borders. Large cascades reduce the number of clicks a board needs and can make two boards with the same settings feel very different.
Chording - Also called Chord click
- Chording means clicking a revealed number after the correct number of adjacent mines has been flagged. The chord reveals every other covered neighbour at once. It saves time, but a wrong flag can make the chord open a mine.
Efficiency - Also called Click efficiency
- Efficiency compares the board's 3BV with the actions the player used. Fewer wasted clicks produce a higher percentage. Efficiency can exceed 100% because one chord action may reveal several cells that 3BV counts as separate left-click units.
Flag - Also called Mine marker
- A flag marks a covered cell that the player believes contains a mine. Flags help with counting and enable chording, but placing every possible flag is not required to win. The real goal is to reveal every safe cell.
Frontier - Also called Boundary
- The frontier is the line where revealed numbers touch covered cells. Most deductions happen there because the visible numbers constrain the hidden cells beside them. Strong players scan the whole frontier instead of staring at one uncertain spot.
Guess - Also called Risk click
- A guess is a click made when the visible clues do not prove that a cell is safe. Some Standard boards force a genuine guess. Other positions only look uncertain because a deduction elsewhere on the frontier has not been found yet.
Mine density - Also called Mine percentage
- Mine density is the number of mines divided by the number of cells. Beginner is about 12.3%, Intermediate about 15.6%, and Expert about 20.6%. Higher density usually creates tighter clues and more overlapping constraints.
No-Guessing - Also called NG mode
- No-Guessing is a mode that serves only boards the generator's solver can finish through deduction. A logical move always exists, although it may be far from the cells that first look stuck. No-Guessing results use a separate ranking pool from Standard results.
Pattern - Also called Number formation
- A pattern is a repeated arrangement of numbers and covered cells whose mine placement can be proved. Common examples include 1-1, 1-2, 1-2-1 and 1-2-2-1. Memorising the answer is useful only when the surrounding boundary matches the pattern's assumptions.
Personal best - Also called PB
- A personal best is a player's fastest accepted result for one difficulty and mode. Standard Expert and No-Guessing Expert are different categories. A leaderboard keeps the best active result rather than listing every game the player finishes.
Satisfied number - Also called Completed clue
- A number is satisfied when it already touches exactly that many confirmed or flagged mines. Every other covered neighbour is then safe. Chording a satisfied number reveals those safe neighbours in one action.
Standard mode - Also called Classic Minesweeper
- Standard mode follows classic Minesweeper rules and may contain positions that require a guess. Its rankings are separate from No-Guessing because board generation and risk are different. Beginner, Intermediate and Expert use the classic fixed board settings.
50/50 - Also called Forced guess
- A true 50/50 is a position where two possible mine layouts fit every visible clue and each gives a cell the same chance of being safe. Before calling a position a 50/50, check the remaining mine count and the rest of the frontier for information that breaks the tie.
Do not confuse these measurements
| Measure | What it answers | What changes it |
|---|---|---|
| Time | How many seconds did the solve take? | Board difficulty, board luck, thinking time and click speed. |
| 3BV | How much minimum solving work did this board contain? | The exact mine layout and the openings it creates. |
| 3BV/s | How quickly did the player complete that work? | 3BV divided by elapsed seconds. |
| Efficiency | How much of the player's clicking was useful? | Wasted reveals, unnecessary flags and effective chording. |
Common term mix-ups
Is every uncertain click a 50/50?
No. A true 50/50 has two mine layouts that satisfy every available clue. If another number, the remaining mine count or a distant part of the frontier breaks the tie, the move was a missed deduction rather than a forced guess. The Minesweeper solver can test whether a typed position has a forced move.
Does a fast time always mean high 3BV/s?
No. A friendly board can open in a few large cascades and produce a low time with little work. 3BV/s accounts for that work. Use the 3BV calculator for a board and the time percentile tool for a live comparison against ranked players.
Are flags required to win?
No. Flags are notes that support counting and chording. A game is won when every safe cell is revealed, even if some mines remain unflagged. The Minesweeper rules explain the exact win condition and first-click behavior.
Choose a next step
- New player: read how to play and use the controls.
- Learning deductions: open the pattern guide and keep the cheat sheet nearby.
- Improving speed: study efficiency and 3BV/s, then compare the Minesweeper.now rankings.