[draconar]

Pinning against the bumps (ramps, whatever) is probably going to depend on the referees' discretion. If the pinned robot has a tank drivetrain and the treads are parallel to the ramp and it can't move, then it's probably pinning. If the treads can go up the ramp but the team just wants to go the other direction, it wouldn't be.
As somebody said above, pinning only happens when a robot can't move anywhere. Otherwise it's just blocking.