go-between vs line judge

go-between

noun
  • An intermediary or middleman. 

  • A shogi piece, used in chu shogi and larger shogi variants, that can move one step straight forward or straight backwards. 

line judge

noun
  • An official who watches the lines of the court and judges whether the ball has landed in or out and also declares foot faults. 

How often have the words go-between and line judge occurred in a corpus of books? (source: Google Ngram Viewer )