[martin417]

A worry I had was that if you build a robot that "vacuums" up all balls it contacts, and you inadvertently vacuum up two empty cells, how can you get rid of one? Most robots of this design will place balls in a hopper and empty the hopper either through a dump mechanism or a shooter.

I also see a strategy where a robot, in possession of an empty cell, passes the outpost. The payload specialist throws a second empty cell into the hopper or where the vacuum will pick it up. That team then either gets a penalty, or has to immediately dump its load, both of which are a bad thing.