Robo-Runners: 4: Powerball by Damian Harvey
Meet Crank and Al ...robots on the run. When the friends arrive at the travelling Iron City, Crank hopes they can all become world-famous powerball stars. But things aren't quite what they expected them to be. Our heroes soon discover that powerball is more than just a game ...it's a matter of life and death, and it takes more than goals for a team to survive.