Professor Lucas Lepri shows an ankle lock defense from the 50/50 guard. Lucas and the opponent are both in the 50/50 guard and the opponent tries to go for a straight ankle lock. As soon as the opponent goes for the ankle lock, Lucas reaches for the opponent’s knee and starts pushing him to the other side by opening the knee. As he opens the knee, he hides his free foot underneath the opponent’s leg and makes sure he keeps his other leg extended. Lucas then switches the grip on the knee and uses his free hand to post on the mat. Lucas then postures up and uses both hands to push the opponent’s legs away from him. In this situation, as soon as Lucas starts to posture up, the opponent prevents him from doing so by using his outside leg to block Lucas’ free leg. Lucas responds by underhooking the opponent’s leg. Using his arm to post on the ground, Lucas lifts his free leg and puts it in between his opponent’s leg and turns his body forward, placing both knees on the mat and lowering his hips to complete the ankle lock.