I'm on a quest to break down applications for the ITF patterns*. I'm using Iain's work of course, the work of Stuart Anslow and Matt Sylvester and also my own training in Thai, Karate, Arnis, BJJ etc. Comparing the pattern elements to the Karate kata they came from, seeing where the influences are. I'm pretty happy with what I've got so far for Chon-ji to Won-hyo but a couple of moves in Yul gok are a bit opaque.
Using this video as reference...
The 2 hooking blocks and the punch (starting at 22 seconds). I like hooking block on its own (brush parry, hook, grab is common in Iain's work) and it feeds well into limb control and other applications but two together don't seem to lend themselves to much. May just use it as a reference that you can block inside and/or outside the attackers arms with your arms (inside outside both arms makes 4 blocks).
The jump into x-stance (from a reverse punch) into a backfist and then into an augmented "block" (at 55 seconds). The x-stance jump is obviously from Pinan Yodan (and others) with the back fist being horizontal rather than vertical. I've seen the vertical backfist used as a dropping elbow (changing the focus on what part is doing the striking) but the horizontal backfist negates that to a large degree.
*I'm aware that the ITF patterns have been put together from an aesthetic point of view rather than a pragmatic one but I'm happy trying to work with the tools I have already rather than put them down and pick up another tool box. :)