above-board vs crystal clear

above-board

adj
  • In open sight; without trick, concealment, or deception. 

adv
  • Honestly; openly. 

crystal clear

adj
  • Visually clear, a sharp image, high acuity. 

  • Completely clear and understood. 

How often have the words above-board and crystal clear occurred in a corpus of books? (source: Google Ngram Viewer )