The berimbolo looks like chaos and works like clockwork. It all comes down to three grips that control the opponent before the inversion ever starts.
The berimbolo is one of the defining techniques of modern sport jiu-jitsu, but the inversion everyone photographs is the last thing that happens, not the first.
Grip one is the De La Riva hook: your shin wraps behind the opponent's lead leg, controlling distance and their base. Grip two is the sleeve, which kills the post they would use to defend. Grip three is the belt or pant grip, which lets you steer their hips as you go under.
BerimboloOnly once those three controls are set does the inversion make sense: you are not rolling under a stable opponent, you are collapsing one you have already off-balanced. Chase the second hook on the way up and the back-take finishes itself.