as for other concepts on defense, there is a post to go to this site
http://fastandfuriousfootball.com
pull up any of these playbooks and get some knowledge!!!!!!!
i looked up the 1993 Oilers and what did I find - FOOTBALL GOLD - as I got to learn the 46 defense straight from Buddy!!!!!!!!!
if is more than X&O's ... it gives you the how/why for everything including foot placement!!!!
easy to follow and use on the mini field.......
k-lo