World Golf Handicap System

The World Handicapping System 2020 (WHS) is an exciting innovation for the golfing world. It was introduced in 2020, starting with many countries in January. Although there may be minor difference between countries, for the first time golfers will be able to directly compare the handicaps with golfers of other countries.

The system was developed jointly by the two key golfing associations, The Royal and Ancient Golf Club of St Andrews (R&A) and the United States Golfing Association (USGA). There was direct input from the existing handicap authorities, such as Golf Australia.

There are two key aspects to the WHS, the Course Rating system and the handicap calculation;

Golf Course Rating System

The Course Rating System used in the WHS is based on the USGA Course Rating System. In its time, the US Course Rating system was also a major innovation. It was based on the work of Dean Knuth when he was at the US Naval Postgraduate School. in the late 1970s.

The WHS provides a detailed method of assessing an golf course to work out the difficulty of that course relative to other courses. The method looks at factors such as the narrowness of the fairways and the number of hazards. The end result is a slope rating ranging from 55 to 155. The higher the rating the more difficult the course. The neutral rating is 113, think of an average length Muni, which is flat, not too many bunkers, and has average width fairways. To understand a slope rating of 155, think of a long championship course, littered with bunkers and water hazards with carries in excess of 150 yards.

Golf Handicap Calculation

The first step is to calculate the differential for your previous rounds. The idea of the differential is to adjust your total score to what it would have been if you played on a neutral course with a rating of 113. The formula is to subtract the total par from your total score and multiply the result by 113 divided by the slope of the course. Suppose you scored on 99 on a difficult par 72 course with a slope of 170. This is a net score of 27, but the differential is 27 times 113 divided by 170 which is almost 18. So the differential is saying that although you scored 27 over on that difficult course, you would have been expected to have played to only 18 over on a much easier course with a neutral slope rating.

The next step is to look at your handicap history and select the last 20 rounds. Identify the 8 lowest scores and take the average of these lowest scores. That provides you with your Handicap Index.

Using your Golf Handicap Index

Your Handicap Index tells you how well you are playing an a course with a notional slope of 113. When you want to use your Handicap Index on a real course, you check the actual slope of the course for the tees you are playing off, and multiply your Handicap Index by the actual slope of the course. This gives you your Course Handicap. For example, if you have a Handicap Index of 18 and playing on a course with a slope of 170, then your Course Handicap is 27. Your Playing Handicap will be normally be your course Handicap.

How will my Handicap Index change

Your Handicap Index will increase but for most players the increase should be less than one stroke. Some countries will compensate for this increase by adjusting the Playing Handicap, so that although your Handicap increases, the actual Playing Handicap for a particular course does not change.

The above is a simplification to allow a quick grasp of the essentials. This page has more detail.