past master vs wiz

past master

noun
  • One who has an extremely high level of ability or knowledge within an area of achievement or expertise. 

  • Someone who has previously been a master at a given lodge. 

wiz

noun
  • A person who is exceptionally clever, gifted or skilled in a particular area. 

  • A wizard; an administrator of a multi-user dungeon. 

How often have the words past master and wiz occurred in a corpus of books? (source: Google Ngram Viewer )