COGENT
| Date | Clue |
|---|---|
| 2014-02-20 | Convincing, as an argument |
| 2010-02-02 | Well-thought-out |
| 2008-03-12 | Convincing, as an argument |
| 2006-04-07 | Telling |
| 2004-10-02 | Telling |
| 2002-02-03 | Convincing |
| 2001-09-23 | Like a good argument |
| 2001-03-24 | Forceful |
| 1999-03-03 | Sound |
| 1997-02-22 | Penetrating |