there are a lot of roller clubs up north as well, they are usually flown in kits of 22 the judges and other competitors usually go from 1 loft to another to view them flying i think they get a 10 minute warm up then they start to judge them on quality and quantity of rolls and ideally they roll together..then after the time has elapsed they count up the total then move on 2 the next lofts......i watched my mates being judged for the world championships............