# Queens attacking exactly four queens

Can you place 14 black and 14 white queens on a standard 8x8 chess board, such that each queen attacks exactly 4 opponent queens?

Good luck!

Here is a related question: Queens attacking exactly one queen

I hope this is correct. First, I noticed that these 8 queens close to the corners fulfill the conditions. Then I tried to add more queens while blocking already set queens to not increase their attacks.

lichess

• Seems right to me, i'm impressed. Tried to solve it for like 30 min without being able to, assumed it would have a 90 degree rotation symmetry but seems like it only needs to be a 180 degree symmetry. Mar 6 '20 at 7:37
• That is exactly the pretty solution I was looking for! Very well done. I wasn't sure that anyone would get it so quickly. Mar 6 '20 at 8:03
• @Dmitry An alternative solution Mar 6 '20 at 11:29
• Very nice Daniel! Please post it as an answer. Mar 6 '20 at 13:39

Interestingly there exist completely non-symmetric solutions:

And this one

• How did you come up with this?
– daw
Mar 7 '20 at 15:20
• I used a computer program based on hill climbing Mar 8 '20 at 0:49