What dirty grooves cost you
A groove on a modern iron is roughly 0.35mm wide. It does not take much compacted soil to fill it. When it does, the ball skids up the face instead of gripping it: spin drops, launch rises, and the shot flies further than expected before running out. That is the flier lie most golfers blame on the rough alone.
Wedges suffer most, because they rely most on friction, and they are the clubs that spend the most time in wet grass and sand.








