Blindfold chess

Blindfold chess, also known as sans voir, is a form of chess play wherein the players do not see the positions of the pieces and do not touch them. This forces players to maintain a mental model of the positions of the pieces. Moves are communicated via a recognized chess notation.

Blindfold chess was considered miraculous for centuries but now there is greater recognition of people who can keep track of more than one simultaneous blindfolded game.^[1] In simultaneous blindfold play, an intermediary usually relays the moves between the players.