Good footwork has several elements (in no order)
1. To move forward (for orthodox fighter) push off back foot and step with front (short step), to move to right, push off left foot and step with right (short step) and so on.
2. Be on the toes of both feet at all times but with more weight on back foot until one punches, then weight shifts to power the shot.
3. Do NOT move in straight lines, move in arcs when enagaging. It makes one far less predictable.
4. Move the MINIMUM necessary to accomplish the immediate objective. It takes less energy and keeps one in punching range.
5. Do NOT cross your feet unless well out of range.
6. Stance at every moment in time should enable one to move in any direction and stay on balance.
Danny Little Red Lopez is a great teaching tool regarding footwork for two reasons. He used excellent technique and he was SLOW so it is pretty easy to see.
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