The Odyssey 2000, released in 1977, is almost an Odyssey 300 with one more game (practice, for one player).
In fact, and as opposed to previous Magnavox Odyssey systems (except the Odyssey 300), the Odyssey 2000 uses the famous AY-3-8500 chipset from General Instruments. This chip offers 4 black & white pong games: Tennis, Hockey, squash (here called Smash) and Practice (squash for 1 player).