Walk Cycles Tutorial

In this YouTube walk cycle tutorial by Alan Becker, I have  learnt the two main poses, 'Contact Pose' and 'Passing Pose', which also relates to the animation process frames of the pendulum that I had learnt earlier. The difference  between the pendulum and the walk cycle however is that there is two filler poses, the 'Down Pose' and the 'Up Pose'.
Alan Becker states that the down pose comes after an contact pose, and an up pose comes after an passing pose.
He states the order should go: contact poses, down pose, passing pose, up pose, contact pose.
But add all contact poses first; then passing pose, then down pose and then up pose.
He also mentions the way arms should be, 'arms are furthest apart on down pose'...'close together on the passing pose'...'arms should be opposite to the legs'.