sweet spot

WordReference Random House Unabridged Dictionary of American English © 2025

sweet′ spot′, 

1. Sport the spot on a club, racket, bat, etc., where a ball is most effectively hit.

• 1920–25

Collins Concise English Dictionary © HarperCollins Publishers::

sweet spot noun

1. the centre area of a racket, golf club, etc, from which the cleanest shots are made
2. a point at which different factors are perfectly balanced or most advantageously combined