This article is a good piece concerning the tactics and strategy of fighting and how the fighting environment, rules, and learning impacts the fight.
A few years ago, the Guard was viewed as a safe place to be. If you pulled guard and were a good JJ/Submission artist you could control and when the fight. Of course, others learned to defeat this strategy.
Does this negate the guard as an important position in tactics and fighting? No.. but what this article show is that their is a time and place for everything and we must constantly be thinking about our environment and the application of our tactics, techniques, and procedures.