It's part of the benefits of cross training. Years ago I tried out over twenty knife counters with trained knife fighters. Out of those only three worked reliably for me. I then figured out why those three worked well and it came down to the proper use of principles. When I got a better understanding of how the underlying principles worked, I was able to use that knowledge and get many of the knife counters that failed for me, to work much more reliably. Turns out that almost everything that works is a variation of some very common themes combined with strong fundamentals. ----------- A trained uke with expertise in something else (e.g. BJJ) can help to find holes in techniques/transitions that should not be there. The hole could be at the very beginning because they keep elbows in and fight for underhooks, or the hole could come later when they are able to speed things up or slow things down to counter because you are not applying constant pressure effectively. Out of six ways, you may only find that one way you use is any good... then use that knowledge to help figure out how to improve yourself in the other five ways. IMHO. Here is a BJJ version of the arm lock demonstrated in JWT's video: [ame="http://www.youtube.com/watch?v=qNEZS_wBFt8"]Gracie Knife Defense - YouTube[/ame] This is the same way I was taught in Kajukenbo for applying the lock, but it was unarmed version where we strike the throat first, then lock the arm. No disrespect to the video or method, but this is caveman version (and I say caveman in a good way). It is the basic way you should start learning the lock. Using both hands and keeping the hands together around the elbow. If hands are separated, you may be able to strike, but the lock is SLOWER. Hands/wrists together is much quicker. From this caveman version of the lock, one can progress to other versions based on their experience and expertise. However, start caveman version, IMHO, because it is the most basic version and understand the underlying principles that make it work. Progress from there.