3 Part Lesson — Marcelo teaches one of his most advanced lessons: [I] When you arrive at the Rear-Body-Lock-Position (back body lock, waist-lock, rear-hold, et al.) be wary of your opponent rolling forward and diving underneath your base; do not treat the position as a static moment or an opportunity to plan ahead based on countering your opponent's reaction. The position is of penultimate importance and therefore too valuable to squander. Convert whatever momentum you cultivated upon your arrival of the control behind the opponent's hips toward further development of Kuzushi. Use the Back-Body-Lock to imbalance your opponent's base, weaken his or her counter-grips against your hands, and open up for a jumping transition to Seatbelt Control. Be careful not to hurt your partner's legs with your falling body-weight. It is better for Uke to fall than to awkwardly support the jump. Counterintuitively, if Tori half-commits to a jump, you place greater danger to your partner than actually aiming high for the opponent's upper back. [II] If your opponent uses your momemtum against you and applies a throw, try your best to land with base and allow your hips to counter-rotate against the toss. Allow your feet to find the floor and immediately begin driving your upperbody to chase the lock. Don't apply high amplitude when training this particualr scenario otherwise you run the risk of injury when landing on bottom. If you both richochet up off the mat back to your feet, start initiating the previous off-balancing sequence as before. [III] Come back strong after landing against any takedown you may suffer, particularly one where your opponent offers an opportunity to take his or her back due to their resultant back exposure (e.g. Makikomiwaza). Train for these situations so that you can reflexively take advantage of the rewarding nature of Back Control. You are one step closer toward finding a finish to the fight and may not get another chance to get a submission.