Aim - Preventing the whole opposition team from blocking your jammer - really useful in a power jam.
The blockers who are on the same team as the jammer on track form the standard 'line' to the side or middle of the track. The jammer then heads towards the wall of blockers lined up across the track picking either the inside or the outside of the track. At this point the line of blockers on the team of the jammer, head to the opposite side of the track to their jammer, pushing through and (as a line, reform directly in front of each of the opposing blockers). While this happens the jammer jukes back and round the line that the blockers have just cleared for the jammer.