Every business day, a round is run. During this round, every participating robot controller will play at least one match against another robot controller.

The Hall of Fame is a table displayed on the web site of the contest, showing the current ranking of all the controllers in competition. New controllers corresponding to newly registered competitors are added at the bottom of the Hall of Fame.

A round is organized the following way: If N controllers are present in the Hall of Fame, N-1 matches will be performed during a round. The first match will oppose the controller appearing on the bottom line of the Hall of Fame (#N) to the one just above it (#N-1). If controller #N wins, then the positions in the Hall of Fame of these two controllers are swapped. The second match will oppose the new #N-1 controller to controller #N-2. If controller #N-1 wins, they will swap their position. The same procedure is repeated with the new #N-2 controller and controller #N-3 and so on until controller #2 and controller #1. If both sides score an equal number of goals, the match is counted as a draw and the controller positions remain unchanged.

This is similar to the bubble sort algorithm: air bubbles moving up to the surface of the water. This algorithm ensures that a controller cannot loose more than one position in one round. In addition, a newcomer entering from the bottom of the Hall of Fame has the opportunity to climb up to the top position in one round (if it is smart enough to win all his matches).