reversal vs stroke of ill luck

reversal

noun
  • A change in fortune; a change from being successful to having problems. 

  • An instance of reversing. 

  • The state of being reversed. 

adj
  • Intended to reverse; implying reversal. 

stroke of ill luck

How often have the words reversal and stroke of ill luck occurred in a corpus of books? (source: Google Ngram Viewer )