Whilst I have been rewatching my DVD's from the beginning, I slowly realised what a great actor Jim Davis was, he made Jock Ewing stand out for me! His acting was outstanding! I loved it when he used to tell JR off, and JR would say "yes Daddy" or "yes Sir"... There was one scene at the evening Dinner table and Jock was talking, and he said "JR, are you paying attention?", JR said "yes Daddy".... Clayton Farlow played by the great Howard Keel was an ok substitute, but in my book the casting was spot on for Jock with Jim Davis, shame he died so soon into the series!