While frequently unused by new or casual golfers, slope and course rating are two of golf’s most important, and most commonly confused numbers. These two numbers might be a seemingly random arrangement of numbers on your scorecard, but in reality, they are two of the great equalizers in the game of golf. Not only do these numbers give golfers an idea of the difficulty between different tee boxes at their favorite course, they also allow players to compare the relative difficulties of a course to others that they have played. This is what I would like to talk about today.
What is a Course Rating?
So what is a course rating anyways? The simple answer is, a course rating is a number that indicates what a scratch golfer (a golfer that averages par for a round) should shoot on this particular course. So, while the par for a particular course might be 72, a course rating of 70.1 would indicate that a scratch golfer should be almost two under par on average. This indicates that the course is actually easier than an average course and allows the player to factor this difficulty into their handicap (and their ego).
What is a Slope Rating?
While the course rating indicates the difficulty of a course for a scratch golfer, the slope rating, by contrast, indicates how difficult the course should be for a bogey golfer (or someone who averages +18 for 18 holes). Also unlike course rating, slope values can range from 55 to 155 with 113 being the average.
Now, although you might be thinking that slope ratings work similarly to course ratings, you are actually falling for one of the most common misconceptions regarding these ratings. Slope ratings, absolutely, do not provide the same information as a course rating. So what do they tell us then?
While course ratings are a measure of the difficulty of a course, slope ratings are a measure of how much more difficult a course is for a high handicap golfer versus a lower one.
For example, if you have two courses that each have a course rating of 72, they should be the same difficulty for a scratch golfer. However, if bogey-golfers on course A averages a score of 90 while bogey-golfers on course B average a score of 95 the slope rating for course B would be higher than for course A; indicating a higher level of difficulty for higher handicap players.
Why Have Two Numbers?
As you may have figured out already, golf is a difficult game and contains a very wide range of golfers, each with very different levels of skill. In the mid 80’s the USGA started to catch on to this big divide between scratch or professional golfers and mid to high handicap golfers.
It turns out that that statistically, no matter how easy or hard a course is, scratch golfers will almost always shoot in the high 60’s to low 70’s. While this might not seem like a big deal, having a very narrow spread of scores even on courses that are much easier or harder than average ones creates a rating that underestimates changes in course difficulties for the rest of the golfing population. However, they also realized that this phenomenon was the exact opposite for mid-high handicap golfers. While one course might only play slightly harder in the eyes of a scratch golfer, less proficient golfers might find their scores to be significantly higher on this new, harder course.
As a result, the course rating designed for scratch golfers was largely irrelevant to anyone over a 5-10 handicap. This left a large majority of golfers without any way to compare the difficulty of courses accurately and presented an opportunity for the USGA to implement their new slope rating system. With the current two rating system, a course rating provides the information about a course’s difficulty for scratch or low handicap golfers and the slope rating provides information about how much harder the course is for high handicap golfers. Regardless of your skill, the USGA has figured out a way to find the right handicap for you, which I personally think is great for the game.
Ratings and Updates
While the course and slope ratings of a golf course are unlikely to change dramatically, they are usually re-evaluated every 4-5 years. This is mostly due to the fact that courses change slowly over time. While small trees may have been planted when a course opened, as they continue to grow they can start to affect play on the course in different ways. Similarly, additional features such as new sand traps or even a change in topography to make room for a new cart path can all be sources of a change in difficulty for a golf course. While these three examples came to mine right away, the USGA website contains a complete list of the things they consider when rating a course.
In addition to physical change, course and slope ratings also change as frequent players learn the ins and outs of the new course because ratings are heavily based off of player scores. For example, while you might not know that a creek bed is dry most of the year during your first round on a new course, after you have played it for a few years you might opt to be more aggressive with an approach shot, knowing that you won’t have to worry about a penalty stroke if you fall short of your target.
These two factors of change, both physical change and increased experience, frequently work against each other and often times nearly cancel out most changes in ratings, however, the possibility is always there. Although many of us spend very little time considering the ratings of courses we play, looking at courses through a different lens, such as how a scratch versus bogey golfer might play a hole, is actually a great way to improve your course management skills.
Although it might not be the most pressing matter for some golfers, understanding how course and slope ratings work is sure to only help you understand the game better in the long run. At the very least, it’s something to think about while you’re comparing the different courses you’ve played throughout the year; hopefully, you’re looking back at some low scores on a really challenging course. So until next time golfers, keep track of those ratings and enjoy your summer golfing season.