arbiter vs line judge

arbiter

noun
  • A person appointed, or chosen, by parties to determine a controversy between them; an arbitrator. 

  • A person or object having the power of judging and determining, or ordaining, without control; one whose power of deciding and governing is not limited. 

  • A component in circuitry that allocates scarce resources. 

verb
  • To act as arbiter. 

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 arbiter and line judge occurred in a corpus of books? (source: Google Ngram Viewer )