Players have a role in keeping the greens  in good condition as they play by routinely repairing pitch mark damage.  Un-repaired pitch marks are avoidable. They cause the grass to die within a few hours leaving unsightly marks on the green. Repair your pitch marks and other damage to the greens as you go. The latest Rules of Golf now allow players to repair or restore all damage to the surface of the green without incurring a penalty. See Rule 13.1c.