Fig. 2.

Trajectory of the ball across the visual field in a typical game. The start position (at one of 10 possible locations in the top row) and end position (at one of 10 possible locations in the bottom row) are chosen randomly. The start position is therefore not predictive of the end position. From the start position, on each timestep, the ball moves to an adjacent pixel on a diagonal trajectory until directly vertically above its end point. In the remaining timesteps, the ball moves vertically downward to reach its final position.