So far, the robots can visualize only the ball and goal, but more information -- fouls, the score, and time left in a half -- can be sent to them wirelessly. Based on these inputs, they scan other lists for things to say and do. One might announce, "One minute left in the half." Or, if the off-field computer tells the other one that a player has kicked the ball out of bounds, it might deliver an explanation of the RoboCup rules.

During unexpected events, say, if a player falls down, someone can type an appropriate comment for the robots to utter ("Ouch!"). The announcers read these phrases using a speech synthesizer. But Veloso uses this trick sparingly, relying mainly on the robots to choose their own actions. "We don't want to make them sound like us. We want to see what they say by themselves," she says.

The two commentators are also programmed to coordinate their actions. Ami and Sango each watch half of the field, since neither can see it all. When one sees a play that the other misses, it sends a wireless message to its partner. Then each decides how to react; after a goal, Ami might dance while Sango says "Score!" They won't repeat one another or talk simultaneously, but instead can interrupt each other. This robot-to-robot exchange -- while each is still watching the field and taking data from computers -- is "challenging," Veloso says.

The robots can't learn yet -- they don't alter their behavior based on what the fans seem to like. But they can adapt to dramatic situations on the field. The programmers have assigned numerical weight to happenings like tie scores, for instance, and if a goal follows a tie, the robots choose more enthusiastic cheers.

Last week, Ami and Sango called RoboCup matches between Sony robot dogs, which are not fast-paced. In other RoboCup games, where the ball races across the field, Veloso says the "information is changing too fast." To call those matches, her group would need to write faster-running programs, she says.

Veloso, who has attended the RoboCup for 10 years, says the event's technology advances each time. "In videos from ten years ago and the videos now, there's a great difference," she says. The robot players are now "more reliable and they perform...soccer tasks more intelligently."