Check out the video of the guys that use the Black Shamrock Training center. They did an impromptu lesson on knife defense for the EKI PR dept and offered to do the whole series of defenses. As usual these guys are the "REAL DEAL" the one guy Dave is competing today at the 'Pyramid" in Long Beach, CA in a SJJIF Worlds 2 day Tournament. The facility is in constant use day and night so Ernie always has sparring partners whenever he can squeeze in a workout-if you ever saw a full contact session it blows the mind of the casual visitors.
https://www.youtube.com/watch?v=fOsBYE_uVlo
https://www.youtube.com/watch?v=fOsBYE_uVlo