A strange little side quest
Between one round of Find 6 Differences and the next, this is worth knowing: The name Tetris combines a reference to four-square pieces with Pajitnov's interest in tennis. There is another connection worth keeping in the same mental pocket: Archery first appeared at the Olympic Games in 1900 and returned permanently to the programme in 1972 after a long absence. It is a good reminder that simple game mechanics can carry a surprising amount of history.