Deep greenside bunkers might scare the socks off of one golfer but present no problem to another. Tight, tree-lined fairways give some players claustrophobia, while others see nothing but fairway. We all have our strengths and weaknesses, which is why the difficulty of a golf course cannot be so easily judged. No one wants his or her handicap based on whether some other golfer thinks a course is easy or hard.
To ensure a level playing field so all golfers can compete on an equal footing, a more legitimate, “science-y†method was needed to determine a player’s handicap. Enter the USGA Course and Slope Rating System.
Course Rating indicates the playing difficulty of a course for “scratch golfers†under normal course and weather conditions. For example, a Course Rating of 72.0 would indicate that a scratch golfer would shoot 72 on that course.
Slope Rating is the measurement of difficulty of a course for non-scratch golfers. It is calculated using the difference between the Course Rating and Bogey Rating (essentially a Course Rating from the “bogey golfer†perspective) multiplied by a constant factor.
In other words, the Course Rating tells how hard the course will play from a scratch golfer’s viewpoint; Slope Rating is from a bogey golfer’s perspective.
The USGA Course Rating System is a complex calculation that takes into account the factors that affect the difficulty of a golf course. Authorized golf associations such as the TGA have teams that carry out the on-course portion of the rating process.
The first step in the rating process is to get an accurate, official measurement of the golf course. Once that has been determined, five playing length factors are taken into consideration for each hole: roll, elevation, wind, dogleg/forced lay-ups and altitude. Based on these factors, the official yardage of the course may be either lengthened or shortened to establish its effective playing length.
In addition to the five playing length factors, Course Rating is calculated by evaluating 10 obstacles on each hole (nine are physical and one psychological). The nine physical obstacles are topography, fairway, green target, rough and recoverability, bunkers, lateral penalty areas, crossing penalty areas, trees and green surface. If those weren’t complicated enough, each hole is given a “boost of difficulty†under the obstacle of psychology.
Each obstacle is given a score between 0-10 (0 being non-existent, 10 being extreme). To avoid any human discretion, the assigned values are taken from a table in the USGA Course Rating Guide. These values are based off the distances the obstacle is from the center of the landing zone or target.
Weighted values are applied to scratch and bogey formulas and then converted into strokes. The Course Rating is calculated by adding or subtracting scratch formula strokes from the Yardage Rating, which is a difficulty evaluation based solely on yardage. To produce a Bogey Rating, strokes are added or subtracted from the Yardage Rating. The Slope Rating is the difference between the Course Rating and Bogey Rating multiplied by a constant factor.
So, how do these numbers affect your handicap? The answer is math. To fully understand how course rating and slope affect your Handicap Index, you must first understand how a Handicap Index is derived.
Handicap Differential =(Score – Course Rating) x 113 / Slope Rating
In simple terms, handicap indexes are calculated by subtracting the Course Rating from your 18-hole score. It is multiplied by 113 (the average Slope Rating of a golf course) and then divided by the course’s actual Slope Rating.
The Course Rating and Slope Rating are important to calculating Handicap Indexes because they are factors that take into account course difficulty. The idea is to equal the playing field. Challenging and easy courses will be rated accordingly, and therefore keep Handicap Indexes fair and reflective of the golfer’s skill.
For more information on Course and Slope Rating, click here.
