Defending Inbound Plays With 2-3 Zone

I purchased Al Marshall's 2-3 zone defense DVD and would highly recommend it. The one area that was not covered is defending baseline inbound plays. Our biggest issue is how to defend the corners. Several teams either start with or send a player to the ballside corner. We also see a flat formation with both corners filled. Who has corner coverage responsibility? I know Syracuse will trap the corner with a guard and forward which is something I'm considering.

Thank you