Archie I think your looking a little to deep into things pigeons have been racing for donkeys years as you know against bigger birdages then today. People in my mind cannot blame the darkness system as in my mind people been doing it for around 12 years or more. You hear especially the older fanciers sending young birds still squeaking and winning the races, they must have had the ultimate stress, but they lasted the whole season. Especially over the last three years, I've heard fanciers say they have young bird sickness but sent the ones that looked alright, which I know happens in clubs up and down the country. Then blame the losses they have received on the convoyers.