few cards shy of a full deck vs few sandwiches short of a picnic

few cards shy of a full deck

adj

  • mentally deranged; demented; insane. 

few sandwiches short of a picnic

phrase

  • Exhibiting disquiet or unsoundness of mind; not sane; mad. 

How often have the words few cards shy of a full deck and few sandwiches short of a picnic occurred in a corpus of books? (source: Google Ngram Viewer )