In April I have been teaching the Half Guard Top position, but instead of the low smashing/passing position which heavily relies on a far side under hook, I have been playing a higher position. I am a fan of half guard bottom (HGB for short), over the years bad knees, hips and legs, in general, has limited my ability play other guards.
Like other guards in Jiu-Jitsu, there have been many revisions to the half guard top (HGT for short) position because of how people in modern-day Jiu-Jitsu are playing half guard bottom (HGB).
For me Eddie Bravo changed my half guard game back in 2004 with his clinch based bottom game, it gave me a new game plan and change my old school perspective of HGB been a bad position. Looking at this from a top player perspective, fighting for under hooks and posture was key, it was from a more upright HGT position I started to develop a knee slice position and back step into leg lock positions.
In recent years there have been more changes and games from HGB (half guard bottom) with people using more frames and sitting up. David Onuma helped me look at and add this to my game, by not accepting the traditional lying down on your side/back position. This means when you are in HGT, you have to break posture, frames and flatten the HGB person out before smash passing.
Z guard/knee shield goes hand in hand with this new sat up/Framing guard position, which creates more blocks/frames to deal with when trying to pass. This is where I have started to integrate more of the Mendes Brothers passing into my game, the position looks like a deep squat and from here I can Knee Slice, Back Step, and leg weave to pass guard.
You also have the option to smash the Z guard/knee shield, but there are ways of attaining a leg lock positions, a great example of this is Craig Jones who often pulls Z guard, Inverts into the Saddle/Ashi.
Here is a break down of the above and what we have been doing in class at BradfordBJJ.com :-