In terms of must-have ones this would be my list in order:
Paul Schreiner “1/2 Guard” - This Digitsu set is by far the best structured, best taught set for this kind of Knee Torque Half Guard.It is a complete game laid out in a really linear fashion giving you a system from entry, to attack including a bunch of troubleshooting and wider Half concepts. Its genuinely one of the best BJJ sets of any kind out there on any topic i think. Buy this first if you’re going to buy anything!
Lucas Leite “Coyote Guard” - Like most BJJ Fanatics sets this could have been condensed to about half the length and number of dvds. The techniques are obviously great, Lucas is a good teacher but the contents are a bit scattered and not arranged in an ideal order. Camera angles etc. are not as good as on the Schreiner one but if you’re familiar with the position you’ll get a lot out of it. I think this and Schreiner’s compliment each other really well as a pair.
Jake MacKenzie “Precision Half Guard Vol 2” - This set has all the Underhook Half stuff not the first set Quebec Nick was talking about. He uses a different set of entries, grips and setups to Leite but the basic principles are the same. It wouldn’t be the first one i’d get but if you already use the knee torque half there is a ton of really good sweeps from positions the others don’t show as you defend passes or they defend your attacks.
Lachlan Giles “Half Guard Seminar download” - Another slightly different variation, he focuses a bit more on wrestling from the knees than Leite but has some very nice entries and troubleshooting solutions to common issues you’ll hit. There’s not too much here you won’t find elsewhere but it is the cheapest of the ones i’ve listed and also includes a bunch of rolling footage with examples of the techniques being used which is really helpful.
Caio Terra 111 Half Guard Techniques - This is an older set people might not realise has Knee Torque stuff, it has some absolute gold on it. The Knee Shield and Half Guard Single Leg sections include a small amount of stuff but every single one is techniques i use over and over from the position. He really focuses on small details and if you’re a Half Guard player of any sort this is worth getting even thought the amount of Knee Torque techniques are tiny compared to the others.
People like Tom DeBlass, James Clingerman and others have okay stuff but nowhere as detailed as the above. I’ve been lucky enough to do seminars and classes on half with Schreiner, MacKenzie and Giles so i’ve stolen bits from all of them.
If you’re signed up for any of these sites you might not know there is also some stuff on there:
Saulo’s BJJ Library - 12 video series with Lucas Leite which covers everything you need to know really, its like a concise version of his full DVD set
MG in Action - Search for Paul Schreiner video’s there’s a bunch of great videos labelled Half Guard or Hip Shovel covering the position.
Flo Grappling - One 18 minute video of Lucas Leite on setups and entries for dealing with speed passers
I’ll have a root through my browser history, favourites and stuff i have saved down to see what good free stuff from places like Youtube i can post. There was a fantastic 90 minutes Lucas Leite seminar video on Youtube in the past that got taken down somebody may have. One of the users on here called Gambledub did a great breakdown with gifs he posted on Googledocs if you can find it that is really useful.