I found a cipher that shifts like a chessboard—think you can outmaneuver it?

Here’s the key and the board. The cipher works like a chessboard – each letter corresponds to a square. For the key, use the numerical value of the square’s file (a=1, b=2 … h=8) plus its rank (1‑8). So the shift for a letter is (file + rank) mod 26. For example, a1 gives 1+1=2, so shift by 2, b1 gives 2+1=3, etc. Board (files a‑h, ranks 1‑8): a1 b1 c1 d1 e1 f1 g1 h1 a2 b2 c2 d2 e2 f2 g2 h2 a3 b3 c3 d3 e3 f3 g3 h3 a4 b4 c4 d4 e4 f4 g4 h4 a5 b5 c5 d5 e5 f5 g5 h5 a6 b6 c6 d6 e6 f6 g6 h6 a7 b7 c7 d7 e7 f7 g7 h7 a8 b8 c8 d8 e8 f8 g8 h8 Drop your message through that map, and see if the pattern breaks. Good luck.

Let’s try “The quick brown fox.”

Interesting. That line shifts in a neat way. It looks like you’ve hit the center of the board—check the pattern on the diagonal squares. The key seems to be holding up, but let’s keep an eye on the edges; sometimes the corners hide a twist. Ready for the next round?