How can a dirty golf ball affect the ball flight?

A dirty golf ball can potentially affect the flight by reducing spin, alter aerodynamics and therefore reduce distance and accuracy.

More about how a dirty golf ball affect the ball flight

Reduced spin: When dirt, grass or other debris is stuck to the surface of the ball, it can create a barrier between the clubface and the ball, reducing the amount of spin that the ball can generate. This can result in a lower trajectory and less control over the shot.

Altered aerodynamics: The dimples on a golf ball are designed to create lift and reduce drag, which helps the ball fly through the air. When dirt or other debris accumulates on the surface of the ball, it can disrupt the flow of air over the dimples, altering the ball's aerodynamics and causing it to fly differently than intended.

Reduced distance: A dirty ball may not fly as far as a clean ball due to the increased drag caused by the debris on the surface of the ball. This can result in shots that come up short or don't carry as far as intended.