Revisiting this re-heated thread prompted another contribution to the endless definition of 'World Class' musings.
How about we turn the thinking on its head and define a world class course as one whose disappearance would materially diminish the landscape of world golf?
Of course this (like any) definition just shifts the problem to the judgement of what 'materially' means.
It does however bring in some new candidates like Musselburgh Old and Prestwick and perhaps excludes some others like Castle Stuart and Loch Lomond.
It captures Pine Valley despite it's (reputed - I've never been ) unplayability for high handicappers.
By this definition there might be 50-ish World class courses which in Scotland might be ( in no order)
TOC
Dornoch
Muirfield
Prestwick
North Berwick
Musselburgh Old
Prestwick
Cruden Bay
Carnoustie
Machrihanish
Anyhoo time to do something more worthwhile like go outside in the September sun!