Defense is a fun subject.

I've found that almost any team can play defense, but very few can do it well.
This year, we picked a defensive robot for our Alliance in Philadelphia based on how well they were able to play defense on us. When first hand knowledge of a defender isn't available (I.E. we didn't play against any) then we go look at who defended powerhouses in the most effective and least risky way possible. I say least risky because defense can go bad really fast, and a defender can rack up a lot of penalties and cards pretty quickly if they over do it.