robotinthreedays wasn't really using a nip contact - they were using pneumatic tires, with a couple inches of contact per wheel thanks to compression. You can really see it in
http://www.youtube.com/watch?v=GT88vWTYgj0 when they're feeding the frisbee through by hand. 2009 and 2012 both had flexible game pieces, so the contact patches got extended by squeezing the balls through a cannon, but this year that give needs to be on the tire instead.