Weekly puzzles 1: chess pieces

I think a possible proof that 7 is also not possible works along the lines that the piece that attacks the other 6 pieces would need to be a queen.

The problem is, you can use a knight to be the one attacking 6 other pieces, like this:


I agree with you that 7 pieces is not possible (or if it is, it would have to be a very sweet solution). The problem is, I think a proof that it is not possible would have to be a tedious proof by cases (it won't work to just look at the "sub-center", i.e the guy who attacks the second most other guys. You'll probably have to go down 1 or 2 more levels, which sounds like a pain to me).

/r/mathriddles Thread Parent