I thought in a 3-Deep coverage each defender plays a third of the field. Which on my opponents defense seemed to work.

http://mfn2.myfootballnow.com/watch/3810#701295
http://mfn2.myfootballnow.com/watch/3810#701318
http://mfn2.myfootballnow.com/watch/3810#701321
http://mfn2.myfootballnow.com/watch/3810#701335
http://mfn2.myfootballnow.com/watch/3810#701377

Then when I call the play the two outside defenders seem to each play half the field, and the other plays the center. Which may not sound very different, but in action has very different results.

http://mfn2.myfootballnow.com/watch/3810#701390
http://mfn2.myfootballnow.com/watch/3810#701338
http://mfn2.myfootballnow.com/watch/3810#701259