Historical clue formulations

• Competitor with variable skills? — 2022-08-11
• Expert problem solver — 2022-04-08
• One who's used to adding pressure? — 2020-05-15
• Competitive problem solver — 2019-10-26
• Brainiac in a certain high school competition — 2019-03-04
• Certain high school whiz kid — 2017-12-16