Exactly two rows contain mines
The four-by-four board has 3, 4 or 5 mines. Exactly two of its four rows contain at least one mine; the other two rows are mine-free. The occupied rows are not identified in advance. Each allowed complete board is equally likely within the selected configuration. There are 288 legal boards with 3 mines, 408 with 4, and 336 with 5.
The next cell depends on what is known
A safe reveal removes every legal board that would have a mine in that cell. The remaining boards determine the conditional safe probability of each covered cell. The hidden board is fixed for the whole round. A safe cell in one row can change the probabilities in another row because all placements obey the shared two-row constraint.
A precise three-mine example
Number cells 0 to 15 from left to right, top to bottom. With 3 mines, the initial support is 288 boards. If cell 0 is safe, 234 boards remain and the gross multiplier is 0.96 × 288 ÷ 234 = 1.1815384615. If cells 0,1,2 are safe, 162 boards remain and the multiplier is 1.7066666667. These are conditional examples, not a prediction that those cells are safe.
One fixed stake and its collection value
The captured stake is deducted once at the start and stays fixed. After a safe reveal, gross collection = 0.96 × captured stake × initial legal-board count ÷ remaining compatible-board count. Gross includes any returned stake. A mine pays zero. The 96% figure is expected gross across the pricing law, not the amount returned on every successful collection, winning frequency or a profit guarantee.
Disabled cells and automatic completion
A cell known to be a certain mine is disabled. The general guard also disables a safe transition above 1,000 times the captured stake and collects automatically when no eligible cell remains. For these three configurations, however, the largest possible multiplier is only 391.68: their support sizes keep every positive quote below 1,000. The guard does not create a reachable 1,000x payout or collection target here.
Reveal and collection controls
Choose the stake and mine count while idle. They and restoration stay locked during an active round; sound remains available. Manual collection becomes available after the first safe reveal. Covered eligible cells can still be selected. There is no automatic queue. Revealing a mine ends at zero; collecting manually or revealing every safe cell ends the round.
Frequently asked questions
Which boards can be drawn?
The four-by-four board has 3, 4 or 5 mines. Exactly two of its four rows contain at least one mine; the other two rows are mine-free. The occupied rows are not identified in advance. Each allowed complete board is equally likely within the selected configuration. There are 288 legal boards with 3 mines, 408 with 4, and 336 with 5.
Why can a reveal change the next cell’s safe chance?
A safe reveal removes every legal board that would have a mine in that cell. The remaining boards determine the conditional safe probability of each covered cell. The hidden board is fixed for the whole round. A safe cell in one row can change the probabilities in another row because all placements obey the shared two-row constraint.
What is an exact example with three mines?
Number cells 0 to 15 from left to right, top to bottom. With 3 mines, the initial support is 288 boards. If cell 0 is safe, 234 boards remain and the gross multiplier is 0.96 × 288 ÷ 234 = 1.1815384615. If cells 0,1,2 are safe, 162 boards remain and the multiplier is 1.7066666667. These are conditional examples, not a prediction that those cells are safe.
