For me I would edit World Class slightly to say that it needs so kind of consistency. Yes you can argue that players have to be consistent to be in the top 2-3 in the world, but there have been many players who have had one great season and never replicated. They might have been in the running that year, but for me that would not be enough. For example when Te'o played fantastically for the lions, some people might have argued that case, but based on form before and subsequently you would say definitely not. I know it's still subjective, but I feel world class players would regularly be mentioned in the top 2-3 of their position, not just once. Some players might also have the potential and ability to be world class, but injuries, form etc...stops them and so you could never call them world class.