In week 15 of the GB curriculum, we will be working on techniques from the GB2 Online course Takedowns by Prof. Henrique Machado.
Have you checked out the GB Online Instagram account?
The setup for the ankle pick employs the Jiu-Jitsu principle of Action / Reaction.
VIDEO 1 - Class 15A - Ankle Pick from Foot Sweep (Kuchiki Taoshi)
From the standard lapel/sleeve grip, Prof. Henrique uses an initial pull/push to create a reaction by the opponent to pull back suddenly. This creates the opening to enter.
Tip: Note how Prof. Henrique changes his level and drops to get underneath his opponent's defensive arms and catch the behind the knee grip. Once he has the knee grip, Prof. Henrique can drive the opponent backwards to unbalance the opponent in that direction and complete the throw to the rear corner.