logrolling vs playing ball

logrolling

noun
  • The act of balancing on a log floating on a river to guide it downstream, often involving rolling it using one's feet; birling. 

  • Mutual recommendation of friends' or colleagues' services or products, such as book recommendations in literary reviews. 

  • The rolling of logs from one place to another; an occasion when people meet to help each other roll logs. 

  • A concerted effort to push forward mutually advantageous legislative agendas by combining two items, either or both of which might fail on its own, into a single bill that is more likely to pass. 

  • A sport in which two people balance on a log floating in a body of water, each one aiming to cause the opponent to fall off by rolling or kicking the log. 

playing ball

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