Historical clue formulations

• Two in a row? — 2026-09-18
• The Yankees and the Red Sox, e.g. — 2025-10-10
• Two in a row? — 2024-05-23
• Hostile parties — 2023-03-26
• Duel personalities? — 2022-11-27
• Adversaries — 2022-10-02
• Opposing forces — 2021-10-16
• Rivals — 2021-04-02
• Friends' opposite — 2021-02-15
• The other side — 2019-07-19
• Enemies — 2019-06-04
• Opposite sides — 2018-05-31
• G.I. Joe and Cobra Commander, e.g. — 2017-04-08
• Anti bodies? — 2016-02-28
• The Jedi and the Sith, e.g. — 2015-12-27
• Two-Face and the Riddler, to Batman — 2013-08-18
• They're not on your side — 2013-07-07
• The North and the South, in the Civil War — 2009-07-06
• Nemeses — 2009-07-05
• They're not for you — 2007-11-23
• They're against each other — 2007-09-28
• Enemies — 2007-07-02
• Grendel and Beowulf — 2006-04-02
• Us and them, maybe — 2006-01-19
• The Blue and the Gray, once — 2005-08-03
• Rivals — 2001-11-12
• Adversaries — 1999-11-15
• Rivals — 1999-08-01
• Opposing sides — 1995-01-18
• Opposing sides — 1994-11-09
• Rivals — 1994-07-02