It was a move that changed everything. Ding Liren, the reigning world chess champion, played his rook to f2—a decision that would not only cost him the game but also his crown. Across the board, the ...

In the game of chess, a rook can move as many spaces as it can in one direction. Or, it can sit stone-still and guard the pieces around it, potentially holding its ground for an entire match — or ...