I’m going to complete today’s four entries with this two-panel contrast from Fritz Lang’s 1943 Hangmen Also Die, chapter 7: Underground. It’s a before-and-after study of people intently following a single move. The board position is impossible to make out but we can be assured that the move was a good one, as each watchful demeanour is transformed by a telling smile.

Thinking about the choices presented by a given chess position can be modeled dynamically  — not for a human thinker of course, but — for a machine intelligence.