During my undergraduate university, the best scores had priority when choosing the limited slot numbers, including the time slots and sometimes which professor

During my undergraduate university, the best scores had priority when choosing the limited slot numbers, including the time slots and sometimes which professor we were to attend. e.g. I would pick Calculus MWF mornings, group two because professor XxXx was in charge; lower grade students who polled agaisnt me would be bumped to a different group, or to a different time slot, or not making it to the lowest grade cut