Here is a good source of information.  There are  interviews and articles by Tony Blauer and his self defense system.

There is some great information on fear management and insight into why the S.P.E.A.R. system is based on upon human genetic responses to violence and danger.  The best thing about the system is that it is geared towards what are bodies want to naturally do in a self defense situation.  If we flinch when something goes towards our head or body automatically, then how do we use that for our advantage, where do we go from there.  Converting that flinch is the key while engaging the attacker until the aggression is over, or you can flee.  Another great aspect of the system is that as it deals with what takes place before a confrontation starts, how it starts, how to position yourself before,  what mindset you should have, how to diffuse or deescalate a confrontation,  how to look for pre-contact clues and adopting a NVP (non violent posture) that is really a fighting stance in disguise.  The best part is that is doesn’t matter what style you currently train in or have in the past as it does not interfere at all.  The system deals with before and during the initial attack, from there you can do whatever you feel is best for you.  If you have no prior training then tools and weapons (strikes,elbows, knee strikes,rakes etc…)  to use can be taught easily.

Here is another important topic by Tony Blauer discussing the Ten Commandments of Street Survival.

Some key points here from physical training to mental mindset and fear management. Good segment on capacity vs. potential. The Ten Commandments are some solid basics we should all try to maintain on a consistent basis.  The last one number 10 is “Thou shalt not rebuke other systems”.  Great point to always keep in mind.  With so much in the martial world you can draw upon many things to enhance your self defense style or system.  By not rebuking other systems you keep and open mind and continue to grow and learn, a closed mindset prevents this.  I think one of the things about the S.P.E.A.R. system is that it is so adoptable with many other styles.  This is why it is being used to enhance so many existing styles being used today. I personally like the simplicity and the “Power of One” (The Spear) as it cuts down on the amount of moves you need to remember in an attack.  My favorite quote form Einstein is “Things should be made as simple as possible, but not simpler”, or DaVinci ,” Simplicity is the highest form of sophistication”.  That’s  what I like about the S.P.E.A.R. system.

Here is a great article by Tony Blauer the founder of the PDR system. It gives more insight to the S.P.E.A.R. system.

Another good article about what makes the S.P.E.A.R. system so effective and easy to learn.  The ability to take a natural reflex or flinch and turn it into a tactic that is both natural and effective can not be understated.  Don’t let the simplicity of a move undermine the effectiveness of its outcome.  You see, fancy and complex motor skills can take years to develop and then in a real attack, when adrenaline is pumping full force, the last thing on your mind will be how to execute a fine or complex motor skill.  Gross motor actions are what is needed to to have the best chance of survival.  I love watching multiple black belts or life long experts in certain arts videoed taped  in a real fight ( actually lets define “real”, they are usually matches in the ring) , they are just swinging hay-makers and punches, etc..  all fine motor techniques go out the window fast.  Are there some guys who can pull them off?  No doubt. Would you want to put your life on it? No way.  Gross motor skills and bigger targets in real situations have the best chance for success in my opinion. Read the article for greater insights.