The real proof of a self-defense technique's effectiveness is not how well the instructor performs the technique, but how easily the technique is taught to and retained by the average student.
As with any training method, competency lies in the application and retention of the technique. Your movements must be both fluid and quick. When practicing, begin slow, concentrating on hand placement and facial strikes.
Kary's method was tested during recent tactical training at the West Virginia State Police Academy by a class of city and county officers. It was also tested on a 17-year-old judo student. On both occasions, people of average ability learned the technique in less then 3 minutes.
Perhaps the best person to testify to the program's effectiveness, however, is Staff Sgt. Tom Smith, a former Marine who was assigned to the Scout/Sniper Marine Corps Reserve Unit located on Long Island. Smith trained at American Combatives for six months, attending classes twice a week. An inter-service transfer to the Navy caused him to discontinue training. A few years passed, and Smith found himself in SEAL training in California. During hand-to-hand combat training, the instructor asked Smith if he had any prior training, to which he responded, "a little." The instructor then demonstrated a roundhouse punch that was to be countered. Smith immediately reverted to the cover-up technique he had learned at American Combatives. He protected himself with face smashes and knee strikes to the instructor's groin, culminating in a face smash takedown. The instructor got up and said, "Thought you said you only had a little training!" Smith did not hesitate in responding to the attack.
Obviously, the techniques in this system are only appropriate for high level threat scenarios, and are certainly not to be used for low to mid-level resistance. They will however, see you through life-and-death situations.