Historical clue formulations

• Three strokes on a par-4 hole, e.g. — 2021-04-27
• See 68-Across — 2020-08-16
• Subpar performance? — 2020-07-16
• Course coup — 2020-06-06
• Golf score of 5-Down under par — 2019-09-09
• Something needed to play the game depicted in this puzzle ... or a hint to the six circled answers — 2017-05-10
• One over an eagle — 2016-08-30
• Duffer's accomplishment — 2008-11-09
• Teller of secrets, in a saying — 1999-10-10
• One under — 1996-08-13