dead center; exact center
Refers to the precise middle point of something, often used in sports or technical contexts.
The arrow hit the dead center of the target.
ボールをラケットの真芯で捉える。
Catch the ball with the sweet spot (dead center) of the racket.
Compound of 真 (ま, 'true') and 芯 (しん, 'core, wick'), literally 'true core'.