Historical clue formulations

• Astuteness — 2025-05-28
• Keenness of judgment — 2021-06-20
• Shrewdness — 2015-09-27
• Sharpness — 2011-07-31
• Keenness of mind — 2011-06-06
• Keenness of mind — 2009-09-22
• Keen insight — 2008-07-09
• Sagacity — 2007-06-01
• Shrewdness — 2006-12-10
• Insight — 2004-09-26
• Astuteness — 2002-07-07
• Perspicacity — 1998-04-24
• Shrewdness — 1997-02-17
• Discernment — 1996-04-02
• Sharpness — 1995-11-12