Pong Doubles was an evolution over the original pong, as it enabled 4 players to play simultaneously. There are two players per team, each controlling its own paddle.

Pong Doubles can also be played in two players mode only.

Apparently, and for once, Pong Doubles was not the first of its kind. Tennis Tourney from Allied Leisure, released in august 1973, claims to be the first 4 players video game ever. It's the same game as Pong Doubles, but released 3 months before (Pong Doubles was annouced in october 1973).