3 Part Technique - Engaging your opponent in his Butterfly Guard is a matter of distance, connectivity, and opportunity; if you're going to close the distance for a pass, always insist on gaining the upper hand with a dominant form of control. Never enter within range of capture without a firm plan in mind, because doing so against someone good will lead to losing positional advantage. While hand-fighting, read your his body for holes in posture: If an elbow isn't protecting against an underhook, knock away his hands and dive inside to take it. If he is defending his armpits well with his elbows held in close, then resort to a Kick-Back Pass ('Standing Step' from kneeling) by leading the hand-fighting away from his head and grabbing onto a strong Collar Tie, as you smack his knee away into Knee-On-Belly. If you feel adequate resistance from his knee or hands while attempting this initial pass, release the Collar Tie for an underhook and drop into his Half Guard for the Over Under Pass. If stuck in a significantly tight Half Guard, remember that short, quick bursts may be required to free yourself rather than one smooth, telegraphed attempt.