The lifetime of a lacrosse ball can vary from person to person so we can’t say for certain, but we can say with confidence that you will never have to throw out a PEARL X or NX for being greasy or hard. We have customers using the same balls they purchased in 2015. PEARL X and PEARL NX balls don’t grease, but may get dirty. You can wash your PEARLS with dish soap and water to clean and remove any dirt buildup on the balls.