perimeter defense sucks. When you get into a tournament setting, it only takes one team shooting well to take you out.
Iowa State has had a lot of time to fix/improve this problem and it still seems to be a major issue.
Maybe someone can provide stats to prove me wrong, but I don't believe last years team was as bad with perimeter defense as this years team. Long and Thomas on defense, especially together, is a recipe for disaster. The rotations are also too late. It's pretty late in the season to improve this. If they play a team in the tourney that is good at shooting, it could be a quick exit.