cojoin vs play ball

cojoin

verb
  • To join together; to conjoin. 

play ball

verb
  • To work together; to cooperate. 

  • An expression used at the beginning of a game of baseball or softball. 

  • To start anything tumultuous. 

How often have the words cojoin and play ball occurred in a corpus of books? (source: Google Ngram Viewer )