A question that I ask myself a lot is how many coverages should I have in my defensive package? I struggled with this question for a long time until I read the book "Football's Eagle & Stack Defenses" by Ron Vanderlinden. On pg. 89 he says, "Although a defense can play all 3 coverages, it is difficult to be thoroughly practiced and effective at all three. I prefer to play Cover 3 in all situations, particularly in run down situations, and I use cover 2 for a change - up coverage." He was speaking about how he plays his "stack" aka 4-3 package and the three coverages he considered using were 2, 3 and 44 (quarters). If a successful college defensive coordinator only carries two coverages.. I am oinly going to carry two coverages!
Every defense is different and some use man coverage (2 man, 1 or 0) as their base look. Some prefer to use zone coverage (4,3,2). Whatever you choose to do should be based on your comfort level as a coach and your personnel. Carry two coverages and become an expert on those coverages!! Do not try to be someone else!! Be an expert at what you coach, and coach your kids with passion, so they will believe that you run the best defensive scheme!