Marcelo briefly discusses with Jeremy about Under-Hook placement: When going directly into the X-Guard from a Hook-Sweep attempt, it is important to hide your neck with your arm when reaching deep underneath for their far-leg; if you leave a gap and don't dive your head along with your arm, your opponent may be able to apply a Cross-Face and sprawl out of your transition. Keep your ear tight against your shoulder as you curl forward and scoop behind their posted knee while keeping their other leg elevated with your Butterfly-Hook. Your opposite arm should remain either high or low to prevent your opponent from pummeling and gaining an Under-Hook; if your elbow is in the middle, they may have the room to weave their hand around your Under-Hook and stifle your advance.