[ahecht]

At the WPI regional, there was not a single yellow card issued for ball-related penalties. There were penalty points for the "basic infraction" in about 1/3 of matches, but these were only in situations where a team kept playing without attempting to free the stuck ball.

As to the one yellow card issued at WPI, that was a situation where two teams collided and one ended on on its side, and then the upright robot backed up and rammed the tipped robot at full speed, pushing it onto its back. There was also a red card issued to a team for the similar issue -- two robots collided and one was tipped on its side, and after the collision the upright bot rammed the bottom of the tipped bot an additional 4 times. However, those were the only two cards issued the entire tournament.