Anderson's main serve is a two-handed speed serve. I've never seen anything close to as fast! The serve he invented, although he really didn't use it that much, is called the California or Avocado serve. This serve is a one-handed serve. The player (rt. handed) positions his mallet in the center of the goal and lets his right thumb hang down on the non-table side of the goal-box. The player moves the puck from the feeder to his thumb. Then by applying pressure with his thumb and moving his mallet quickly forward, he can quickly serve and shoot the puck using his left-hand as a decoy.
From the Air Hockey listserve.