on the first yb race last year we had 30 ybs all we sent back within 30 mins of each other alot of people in the fed had massive losses some with 80 birds a friend of someone in our club sead they were all blown on the coast yet no one in are club had big losses if any at all so i think positioning and weather have a big role in yb losses but personaly i would put it down to people sending birds that are not 100% the person who had massive losses toped the west durham amal with old birds so must know what hes doing so maby im wrong its a mystery.