An extended feed is a passing pattern for four or more people. The jugglers stand in two straight lines, with the people in each line facing toward the other line. The lines of jugglers are staggered so that no one is standing directly in front of someone else.
Except for the two people farthest from the center of this formation, each person juggles like they would if they were the feeder in a 3-person feed: They pass with the two people in front of them, alternately throwing to the left and to the right. Every time the feeders pass, either all of them throw to their left or all of them throw to their right.
The two people at the ends each have only one person to pass to, so they juggle like the feedees in a 3-person feed. If the feeders are doing 2-counts, the people at the ends do 4-counts. In an extended feed with an even number of people, the two people at the ends pass at the same time. In an extended feed with an odd number of people, the people at the ends juggle out of time with each other like the feedees in a 3-person feed: Whenever one of them is passing to a feeder, the other one is doing a self throw.
4-person extended feed
(also called a W-feed)
6-person extended feed