Identify which squares lie on the same diagonal. Understanding diagonal relationships helps you visualize bishop and queen attacks, and spot pins and skewers without seeing the board.
Pro tip: Diagonals always connect squares of the same color.
New here? Read the chess coordinate training guide.
60s
Leaderboard
About Diagonals
Seeing which squares share a line
You are shown two squares and you answer whether they sit on the same diagonal, as many pairs as you can in 60 seconds. It is the inverse of tracing a bishop's reach: instead of expanding outward from a piece, you test a relationship between two points. That is the operation you actually perform in a game, because tactics do not announce themselves as attack maps, they show up as a question about whether a bishop on g2 is looking straight at a rook on a8.
The arithmetic is simple once you name it. Two squares share a diagonal when the difference between their files equals the difference between their ranks: c3 and f6 are three apart in both directions, so they are connected. If the differences do not match, they are not, no matter how close they look. A faster first filter is colour, since squares of different colours can never share a diagonal, which rejects half of all pairs instantly. This is the recognition that finds pins, skewers, and long-range bishop threats before they arrive. Train the outward direction with bishop movement, the parity shortcut with the same colour drill, and put it under pressure in attack detection.