Fighting Stance 3 (Position Zero)
Stand hip-width apart with both feet pointing forward. For orthodox, turn your right foot out until it is perpendicular to your left foot (or the reverse if you want to stand southpaw). Take a big step back until your heels are slightly past your shoulders. Your feet should look like the letter "L" when you look down. ("J" if you are standing southpaw.)
Imagine sitting on a high stool with only your rear glute. Your lead glute is completely off the stool. You don't want to lean all your weight back until you fall off the stool, but you also don't want to carry half your weight on your lead leg, which defeats the purpose of the stool.