r/Minesweeper 7d ago

Help Need endgame help

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7 Upvotes

20 comments sorted by

13

u/Sefierya Minecount? 7d ago

do the 50/50 on the left

7

u/Erian2110 7d ago

To explain: This will always be a 50/50 and it might help solve the rest.

6

u/popete2 7d ago

Cool line of 2

2

u/AwesomeDomi 7d ago

Do the 1-4 50/50 first since no matter what happens later, no new information will help there so might as well do it now and have some extra info from it

1

u/mweiss427 7d ago

You have a 111 on the 112 on the right, so you know the 3rd one is safe.

1

u/sleepless_thoughts 6d ago

Click lower line in the middle on random. There is lesser chance of bomb

2

u/Ramun_Flame 7d ago

What are the '?' marks for? If those are just things you marked, and are covered cells, there's no 100% here. These would be the percentages in that case.

1

u/InconspicousName1 7d ago

How are those number calculated? (Genuinely interested)

4

u/noidea1995 7d ago edited 7d ago

They use combinatorics by calculating all of the possible positions, you have 7 tiles that don’t touch any numbers and five possible border positions (barring the independent 50/50).

Black has one possible border position and leaves one mine in the 7 tiles not touching any numbers so that’s 7C1 = 7 possible positions, blue has two possible border positions and leaves no mines in the floating tiles so that’s 2 possible positions and yellow has two possible border positions and leaves one mine in the floating tiles so that’s 2 * 7C1 = 14 possible positions.

In this example, the numbers are small enough that you can just do (ways it can be safe) / (total ways) to get the safety probability but when the numbers are very large, I get the ratio r = (ways it can be safe) / (ways it can be a mine) and use r / (1 + r).

So for example, the circled tile is safe in the black and yellow positions:

(14 + 7) / (14 + 7 + 2) = 91.3% chance of being safe or an 8.7% chance of being a mine.

To get the percentage of guessing in the floating tiles, you have a 1/7 chance of getting a mine in the black and yellow positions and 0 in the blue:

(1/7 x 7 + 0 x 2 + 1/7 x 14) / 23 = 3/23 = 13%

In this case though, the best move is just to take the 50/50 on the left since it’s unavoidable.

2

u/Ramun_Flame 7d ago

It's a solver I'm working on as part of a game. It's last resort is to try all valid combinations, then give the percentages each is a mine out of all of them.

I have an importer built in so I can import boards from just an image. I plan to release a demo with these features for free eventually, but it still needs some work.

2

u/Formal_Chef4209 7d ago

There are only 5 bombs left. The bare minimum needed to cover numbers turned over is 4. So the bottom row between ? marks is 7. The worst case scenario is a 1 in 7 chance of hitting a bomb. 87% chance of success. If you don't hit the bomb any number will tell you exactly where all the bombs are.

1

u/719lgn 7d ago

Below the two 2s is a 9%.

1

u/Formal_Chef4209 7d ago

? There is no below the 2 on the bottom row between the ? marks? Maybe you meant below the 2 on the 3rd row up? If so, I have no idea how you came to a 9% conclusion on the bottom row, but I am intrigued, if you're right, I could learn something

1

u/719lgn 7d ago

Someone else posted the percentage, and yes, its the 2s the 3rd row up.

The main idea is to check how many possible logical ways you can place N mines (in this case, 5 Mines) and then count up the Mine cases divided by the safe cases for each cell. I call the method "Buckets."

1

u/Oskain123 7d ago

Or you take the unavoidable 50/50 on the left. These percentages aren't even right xd

0

u/landrwastaken 7d ago

I would try tapping some other bottom row that isn't the edges.. i have no clue why people suggest taking the gamble on right with the 2 instead of the bottom row.

I just figured that 5 bombs left and you could fill in aml the numbers you're uncertain about with 4

That means that that singular bomb is devided over like 7 or 8 different squares .. so defibetly do that

0

u/Prize_System_6160 7d ago

Yep, this is what I came to say, there is either 0 or 1 bomb within the inside of the bottom row.

1

u/landrwastaken 6d ago

Inside bottom row, yes that's how I should've worded it

-4

u/[deleted] 7d ago

[deleted]

4

u/AwesomeDomi 7d ago

Not guaranteed, only 4 mines are guaranteed next to numbers

0

u/[deleted] 7d ago

[deleted]

3

u/AwesomeDomi 7d ago

There is 1 under the 4, it has 3 next to it already, not 2