The "knee slice" is a technique commonly used in Brazilian Jiu-Jitsu (BJJ) for passing an opponent's guard. It involves positioning your knee across the opponent's thigh while using your body weight to create pressure. This movement helps to open up the guard and allows the practitioner to advance to a more dominant position, such as side control. To execute the knee slice effectively, the practitioner must maintain good posture and balance while controlling the opponent's hips. Proper timing and angles are crucial, as they help to prevent the opponent from recovering their guard or countering the pass. Mastering the knee slice can significantly enhance a practitioner's grappling skills.