Slope and Course Rating: How They’re Defined, “These Important Numbers”
There are some numbers on your scorecard that are almost as important as the scores you write down for each hole: slope and course rating.
To some golfers, checking the slope and course rating before teeing off is part of their normal pre-round routine – other golfers never look at them and wonder what the numbers mean, how they’re figured and why they’re important. Here are the answers to those questions.
Course ratings have been around since the Ladies Golf Union began the practice in 1893 in Great Britain. By 1911, the USGA was rating courses in the US. The rating, which is generally a number somewhere between 66 and 77, represents the average score that a scratch golfer (handicap 0) would shoot on the course.
Since most golf courses have several sets of tees that vary the length the course plays to, each set of tees has its own course rating and these course ratings usually differ by several strokes.
The rating, which is generally a number somewhere between 66 and 77, represents the average score that a scratch golfer (handicap 0) would shoot on the course.
The slope rating has a much briefer history. It first came into use in the 1980s and by 1990 the USGA required all facilities with course ratings to also be slope rated. The slope rating is a number between 55 and 155 and the number represents the relative difficulty of the course for a bogey golfer compared to a scratch golfer. The higher the number, the harder the course is; the standard, or average, course slope rating is 113.
Score – Course Rating * 113 / Slope = Handicap Index ⛳️ pic.twitter.com/g1YTMBjyax
— Sean Morrissey (@Sean_Morrissey) September 12, 2016
(The term “slope” itself actually refers to the mathematical slope on a graph that would illustrate the straight-line rise in anticipated scores as courses become more difficult for the bogey golfer.)
In the United States, local golf associations are responsible for calculating both course ratings and slope ratings using specific criteria determined by the United States Golf Association.
Course ratings are generally calculated by teams of trained raters who take into account up to 11 variable rating factors on each of the 18 holes. These include the length of the hole, whether it’s uphill or downhill or dogleg, the numbers and types of hazards, general course conditions including prevailing winds, and the difficulties of the green complexes. In all, the ratings are based on over 450 measurements from each set of tees and include both the standard course rating and a separate bogey rating. (In over 2000 rounds of golf in 40 years, I’ve never seen a course’s bogey rating displayed on a scorecard).
The slope rating then is a calculation based on a formula using the difference between the USGA course rating and the bogey rating to compute individual handicaps from each set of tees.
Why are the course rating and the slope important?
Well, if you’re just out by yourself and you’re not competing with anyone, or if you don’t have a handicap index, they’re not. But if you’re having a match with someone based on handicap or are playing in a tournament, the ratings will determine your handicap for the course you’re playing that day.
Using the Slope System, a course handicap can be significantly different from a player’s handicap index.
For instance, a player who has an index of 8.2 will play as a 7 handicap on a course with a slope of 100, but on a course with a slope rating of 130 he’ll play as a 9. Someone who has an index of 16.8 will play the same courses as a 15 and a 19.
So on one course the higher handicap golfer receives 8 strokes from the lower handicap player, on the other course he gets 10. If you don’t think that’s an important difference, you’ve probably never won or lost a match by one stroke.
And in case you’re curious, the highest slope/course rating in the US belongs to the 8,325 yard, par 73 Pines Course at The International in Bolton, Massachusetts. The slope on this private course is 155 and the course rating from the back tees is 81.7.
For more information on slope and course ratings, check out these links: