Dan Fagella, of The Science of Skill, has recently begun to offer what he calls Micro BJJ videos and articles. If you're not familiar with Dan he's a brown belt in the Rooster/under 130lb division. Dan has been competing at the highest levels most recently winning the NoGi Pans as a brown belt in 2011. Outside of BJJ he is working on his PhD at Univ of Penn with a focus in psychology.
In the MicroBJJ series Dan takes a fairly specific technique or situation and breaks it down to a very high level of detail. Many of these articles and videos focus on leg locks, an area of intense interest to him. Dan was kind enough to provide a copy of his Heel Hook Secrets video and as part of the review I'll be breaking it down into a handy-dandy map for your easy reference.