Who provides the Course Rating and Slope Rating for each golf course? 

Washington Golf along with volunteers conduct the on-course rating of all golf courses within Washington Golf territory (Washington State and Northern Idaho). Other State Golf Associations conduct the on-course rating for all of the golf courses within their jurisdiction.

The Course Rating System™ is what allows players to use their Handicap Index® at the various courses and sets of tees they may play. Without the dedication of WA Golf staff and their volunteers, the World Handicap System™ would not function successfully.