lomaca, you have just backed up my theory without realising. You suggested that the big blokes carrying the extra (body) weight did not perform as well as the little blokes. You both had packs on your backs but the big blokes were carrying extra body fat, probably 5 to 10 kilos above your optimal fitness. If you carry that logic through to a horse then an extra couple of kilograms in the saddle bag, or a heavier jockey, doesn't have nearly the impact that the total mass of the horse has. Say the horse has another twenty kilos to lose to get to optimal fitness. And we are worried about two extra kilos shown in the form guide?