Nearly two years after it was first unveiled, the World Handicap System (WHS) is about to take effect.

The U.S. is one of several countries that will adopt the WHS, which was crafted by the USGA and R&A in conjunction with the existing worldwide handicapping authorities. While the system will be officially implemented in the U.S. by mid-January, the program’s roll-out will continue throughout 2020, with Great Britain and Ireland adopting the program in the fall.

But for golfers in North America, the rules are about to (slightly) change. Here’s what you need to know about the new way to calculate a handicap: (Click here for more information from the USGA)

Streamlined calculations

Currently there are six different handicapping systems in use around the world. The WHS will become a singular, unifying system that will allow players from all parts of the globe to effectively compare their relative skills and bring an accurate handicap with them when they travel to courses around the world.

Course and slope ratings

A key principle of prior handicap systems, course ratings will be expanded and will serve as the foundation for handicap index calculations under the WHS. The course rating, which indicates the expected score for a scratch player from a given set of tees, and the slope rating, which expresses the difference in difficulty between a scratch golfer and a bogey golfer, will be the primary factors in handicap math.

Optimistic evaluation

While many current handicap systems currently count a player’s 10 best scores out of his/her 20 most recent rounds, the WHS will count only the best eight scores in a 20-round span. This means your number could soon shift by a few decimals without any additional scores, as good rounds will receive more weight and a player’s handicap will more closely reflect his/her ability on a good day than an average one.

Impact of weather

As any avid golfer can attest, a higher score in tough weather conditions can sometimes be a better performance than a lower score on a calm day. In addition to standard course and slope ratings, the WHS will also include a “playing conditions calculation” that will potentially adjust scores based on abnormal weather. The range for this calculation will be from -1.0 (for easier than expected conditions) all the way to +3.0 for especially inclement conditions.

System safeguards

The new system also boasts features that will prevent a player’s handicap from rising too quickly. A memory of past performance will be factored into future calculations, meaning that a player’s low handicap within the past 12 months will be used as a factor to “cap” a handicap and prevent it from rising too quickly because of a short run of poor form. The system will also automatically adjust if a single low score is more than seven shots below a player’s current handicap index, triggering an “exceptional score reduction” that lowers a handicap to more accurately reflect ability.

Flexibility

In an effort to create a more inclusive system that will allow players from around the world to stand on a level playing field, the WHS offers more flexible options for posting scores. Now a player can receive a handicap after submitting scores for as few as 54 holes, and scores can be submitted either as 9- or 18-hole rounds. Scores can also count from tournament or recreational play, and in stroke or Stableford format. However, as with current USGA regulations, a round played alone will not count for WHS handicap purposes.

Scoring

Under the new system, the maximum handicap for both men and women will be raised to 54.0, a significant increase from previous ceilings. The highest score on any given hole will be a net double bogey, replacing the previous component of equitable stroke control.

Timeline

The new system will launch in January in the U.S., Canada, Mexico, Republic of Korea, Australia, Argentina, Venezuela, Uruguay, Panama, South Africa and India. It will go into effect by April in New Zealand, Hong Kong, Singapore and Sweden. Portugal will adopt the new system in the summer, while Great Britain and Ireland will adjust by November.