It might be easy to overlook the course and slope rating of a golf course you’re about to play, but having an understanding of these two numbers can allow you to set your expectations ahead of time, or even make you realize that a course may not be suited for you. So what are these numbers, what do they mean to you, and how are they calculated?
The course rating is telling you how difficult a course is for scratch golfers (0.0 handicap) and is expressed as a number of strokes, usually with one decimal place – so in other words, how many strokes a scratch golfer would be expected to take on average to play the course under normal conditions. For example, a course rating of 72.5 means that a scratch golfer is expected to shoot an average of 72.5 on that course – if the course has a par of 72, that would mean it’s a slightly more difficult course than average for a scratch golfer. It is calculated by a team of experts who visit a course and evaluate various factors that affect the playing difficulty of each hole, such as length, obstacles, elevation, wind, etc, with a scratch golfer in mind.
Slope rating is a measure of the relative difficulty of a golf course for a ‘bogey golfer’, ie a player with a handicap index of approximately 20.0 for men and 24.0 for women. It is expressed as a number between 55 and 155, with 113 being the average. The slope rating tells you how much harder the course is for a bogey golfer compared to a scratch golfer. The higher the slope rating, the more strokes a bogey golfer would take compared to a scratch golfer. The slope rating is also determined by a team of experts who evaluate the same factors as the course rating, but with more weight given to factors that affect the bogey golfer more, such as length and where the obstacles are in relation to the average bogey golfer’s driving distance, for example.
To calculate the slope rating of a course, the experts first determine the ‘bogey rating’, which is the number of strokes a bogey golfer would be expected to take on average to play the course under normal conditions, using the factors mentioned above. Then they subtract the course rating from the bogey rating and multiply it by a constant factor of 5.381. For example, if a course has a course rating of 72.0 and a bogey rating of 94.0, its slope rating would be (94.0 – 72.0) x 5.381 = 118.3. This would mean that the course plays a little more difficult for a bogey golfer than a scratch golfer.
Why do we need them?
In the most simple terms, you can get a good idea of how the course will play for you – if you are a high handicap golfer, and the course has a slope rating of 145, it might not be the best course to play unless you’re up for a big challenge and have a lot of spare balls!
The slope and course rating are also used to calculate your Course Handicap, which is the number of strokes you receive or give on a specific course based on your handicap index. To find your course handicap, the slope rating of the course is divided by 113 and multiplied by your handicap index. For example, if your handicap index is 15.0 and the slope rating of the course is 125, your course handicap is (125/113) x 15.0 = 16.5 (rounded to 17), again showing that this course will play a little more difficult than an average course for you.
The course rating and slope rating of a golf course are not fixed numbers. They are subject to change based on various factors, such as course modifications, weather conditions, maintenance practices, etc. The USGA recommends that golf courses should be re-rated every 8 to 10 years, or sooner if there are significant changes that affect the playing difficulty of the course. The USGA also conducts periodic reviews of existing ratings to ensure their accuracy and consistency.
Knowing the course rating and slope rating of a golf course can help you estimate your course handicap and plan your strategy for playing the course. To find out the ratings of any golf course in the US, you can use the USGA’s National Course Rating Database online or check with your local golf club or association.