Have you ever wondered how your Handicap Index® is calculated? Well, it starts with Course Rating™ and Slope Ratings™. The method through which these numbers are determined is part art, but mostly science. But it isn’t science that only Bryson DeChambeau can understand. Most of these items are obstacles you face every hole as a Scratch or Bogey golfer – you just need to understand how these factor into the Ratings.
Each CDGA Member Club is rated every 10 years, unless they had major changes to the length or di iculty of the course. CDGA Course Raters rate about 50 courses every year using this methodology.
Here is what the process for a rating looks like:
The team leaders may use Google Earth to get preliminary data before evaluating the course. The CDGA confirms the data on the course using GPS, elevation apps and laser range finders. We then consult with the superintendent for maintenance practices that produce the mid-season green speeds and course rough height. We also verify the accuracy if we do the rating in mid-season. Measured using a “Stimpmeter,” greens typically fall into three speed ranges: <10´, 10´–11´ or faster than 11´.
We have three to four teams of two people each, all arriving around 6:30 a.m. Two teams are responsible for rating the holes from the most frequently played tees within the system for men and women. One team rates the greens. In total, doing this process for all 18 holes usually takes about 4 hours. Then we reconvene back at the clubhouse for another hour to correlate our field data based on the Course Rating System Guide Book. Nearly 40 unique data points are taken into account for each hole.
The length of the hole is more than what is on the card. Length (including adjustments) makes up approximately 85 percent of the Rating and Slope.
The effective length is made up of the following:
● Roll – the USGA says the average roll is 20 yards in mid-season.
● Dogleg – do you hit less club because of the dogleg or more to clear it?
● Forced layups – do you hit less club so you don’t go into a penalty area that bisects the fairway?
● Elevation – if the hole is uphill, the roll is less; downhill, the roll is more.
● Wind – is the prevailing wind into or with a player's shot?
● Altitude – no impact in Chicago, but if you are playing in Denver, your ball will go about 10% further than at sea level.
Also taken into account are 10 obstacle factors:
● Topography – what is your stance like in the landing zone? Is the shot uphill into a green?
● Fairway – fairway width on your first, second or third shot is measured. Fairway tilt is taken into account because it might deflect your ball into the rough. Fairway bunkers are also taken into account if in the landing area and how close they are to the fairway.
● Green Target – how big is the green, and the length of the shot into the green are factors based on USGA shot dispersion pattern data.
● Recoverability and Rough – the penalty for missing the green or fairway.
● Bunkers – what percentage of the green is surrounded by bunkers and how deep they are increases the di iculty.
● Crossing Obstacles – carries over water, penalty areas and extreme rough are evaluated.
● Lateral Obstacles – penalty areas, extreme rough, out of bounds and closeness to the fairway are factored in.
● Trees – location, size and density are taken into account. If there are chutes from the teeing area or closeness to the greens.
● Green Surfaces – speed, contours, slope and tiers are factors that affect putting. Also, the closeness of the bunkers and mounds to the putting surface affects the short game.
● Psychological – how do all these factors affect the mind of the player? This is an additional rating for each category of player based on the cumulative impact of hard obstacles.
Once the process is completed and the information is submitted to the USGA, the CDGA Member Club is provided with the updated Course and Slope ratings and the World Handicap System is updated. The next player to enter their score will receive the proper Differential to impact their new Handicap Index!
Hopefully, this provides some helpful context regarding how the courses you play are rated. It uses some art, but mostly science. Each course in the world is rated the same way.
David S. Taylor has been a CDGA Blue Coat since 2023. He is one of nearly 50 CDGA Course Raters