A strange little side quest
Before the next round of Riffle Assault, here is a piece of the bigger picture. The word 'checkmate' is linked to the Persian expression 'shah mat', used when the king was trapped. A second detail makes the picture even better: In 1958, Tennis for Two used an analog computer and an oscilloscope to turn simple physics into a playable tennis-like demonstration. That gives Riffle Assault a little more company than it first appears to have.