MineOnline
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3BV stands for Bechtel's Board Benchmark Value. It is the smallest number of left clicks that clears a board if you never flag and never chord. A low 3BV means a board with a few big openings; a high one means a board full of small numbers you have to open one by one.
How to count it
- Every opening counts as 1. An opening is a connected group of empty tiles (zeros) together with the numbers around its rim. One click on any of the empty tiles opens the whole thing.
- Every number that touches no empty tile counts as 1. Nothing opens it for you, so it costs its own click.
Add the two and you have the board's 3BV. Mines never count.
Typical 3BV per board
| Board | Average | 8 in 10 boards | Seen |
|---|---|---|---|
| Beginner (9×9, 10) | 15 | 9–22 | 2–38 |
| Intermediate (16×16, 40) | 64 | 49–79 | 27–120 |
| Expert (30×16, 99) | 171 | 147–196 | 103–255 |
These are measured over 20,000 boards of each size as MineOnline deals them (the first click and its neighbours are never mines). An Expert board of 150 and one of 195 are both ordinary, and the second is nearly a third more work.
3BV per second: your real speed
3BV/s is the board's 3BV divided by your time in seconds. It answers the question a bare time cannot: was that fast, or was the board easy? Clearing a 171 board in two minutes is 1.43 3BV/s. Clearing a 140 board in the same two minutes is 1.17: the same time, clearly slower play. The best players in the world sustain more than 3 on Expert.
Because it corrects for the board, 3BV/s is the number to track from week to week. Your best time will always come from an easy board; your 3BV/s shows whether you are actually getting quicker.
Efficiency: how many clicks you really needed
Efficiency is 3BV divided by the clicks you made, as a percentage. In MineOnline every click counts, flags included.
- Below 100%: you clicked more than the theoretical minimum. Normal: wasted clicks, flags that unlocked nothing, tiles opened one at a time.
- Around 100%: clean no-flag play, or flagging that just pays for itself.
- Above 100%: only possible with chording, where one click opens several tiles that would each have counted toward the 3BV.
Where you see it
Every finished run in the Drill Yard shows the board's 3BV, your 3BV/s, your clicks and your efficiency. On the leaderboards each time opens a small panel with the same numbers and a replay, so you can check whether a record was a monster run or a gift of a board. If you blow up, the result shows how much of the 3BV you had cleared.
Using it to get faster
- Low 3BV/s but high efficiency: you play cleanly and slowly. Work on reading speed with the patterns.
- High 3BV/s but low efficiency: your hands are fast and wasteful. Flag less, chord more.
- Chasing a record: restart quickly on a high-3BV board. Chasing skill: finish every board and watch the average.