Which Course Is More Difficult?

MYTH #1 -- Slope is the primary indicator of difficulty or, to put it another way, the higher the slope, the more difficult the course.

WRONG!  Course Rating defines course difficulty.

As each score a golfer posts is broken down into a numerical value known as a “differential,” it is the Course Rating that plays the more important role in the calculation (Adjusted score minus Course Rating multiplied by 113 divided by the Slope Rating).  Slope merely bumps the number arrived at from the Course Rating up or down to a different differential.

To put the Course Rating vs. the Slope Rating into perspective, it takes more than 20 units of Slope to have the same impact on a course handicap as a single stroke of Course Rating for a 5-handicapper.  As a golfer’s handicap level increases, this ration of the importance of the two values changes, but even for a 20-handicapper, it takes 5 to 6 units of slope to have the same impact as one stroke in the Course Rating.

Myth #2 -- Two courses with the same Slope are of equal difficulty.

WRONG!  A course with a rating of 71.5/125 is about two strokes more difficult than a course with a rating of 69.6/125 at EVERY handicap level.

Myth #3 -- Slope ratings can be compared among courses.

WRONG!  There is nothing more dangerous than trying to draw any sort of meaningful conclusions by comparing Slope Ratings from one course to another.

So what is Slope?

Slope merely tells you how “proportionately” more difficult a particular set of tees plays for the higher handicap golfers as opposed to the lower handicapped golfers.   The more difficult the tees play proportionately for higher handicappers, the greater the Slope rating that will be issued. That’s it! 

Actual difficulty is measured via a Course Rating process that objectively evaluates a number of factors on each hole and each shot through the eyes of a scratch and bogey golfer.  This process is so thorough that an actual rating for the bogey golfer is computed and it is the gap between the Scratch and Bogey rating that determines the Slope.

For example, a set of tees may be issued a Course or Scratch rating of 70.5 and a Bogey Rating of 94.3.  What this means is that if a scratch golfer were to complete 20 rounds from this set of tees, we expect his 10 best scores to average around 70.5 and the best 10 scores from the bogey golfer to average around 94.3.  Based upon this gap of 23.8 strokes between the two ratings (94.3-70.5=23.8), a Men’s Slope Rating of 128 would be issued (23.8 X 5.381).

The scratch and bogey ratings are somewhat volatile, and when a series of factors or obstacles on a golf course tend to gang up on only one of the two golfers, curious things can happen to Slope.  For example, if a set of tees has a higher number of holes in which the bogey golfer can reach the greens in regulation, simply because of the length of the holes, an upward pressure on the slope will be exerted.  Think about it…on most of these holes the bogey golfer is approaching that green with a long iron or fairway wood while the scratch golfer has a wedge or less in his/her hands.  Clearly the bogey golfer is more susceptible to any of the greenside troubles present on the hole such as bunkers due to the diminished accuracy of the club required to reach the green.  These kind of greenside troubles are the kind that can cause scores to soar, forcing the bogey rating higher and widening the gap between that scratch and bogey ratings resulting in a higher slope.

Now consider a set of tees, even on the same course, where most of the holes are unreachable in regulation for the bogey golfer but reachable for the scratch golfer.  Now it is the scratch golfer who has the longer approach shot, perhaps with mid to long irons, while the bogey golfer may merely be chipping/pitching to the green in one over regulation.  To a certain degree, the tide of proportionate difficulty has turned.  Although BOTH ratings will increase because of the added length of the tees, the gap between the scratch and bogey rating may be considerably less resulting in a lower slope.

These upward and downward pressures help explain why a Slope rating may increase sharply at a course from the front tees to the middle tees simply because the bogey rating rises mush faster than the scratch rating as approach shots become longer.  Yet the slope rating may not change significantly from the middle to back tees because the gap does not increase significantly due to shorter approach shots of the bogey golfer.  It also explains how a shorter course can be issued a Slope rating that may “feel” a little high, or how a longer course may be issued a Slope rating that may “feel” a little low.

Another factor that can greatly impact the Slope is forced lay-ups.  If the Scratch golfer is forced to lay-up on a hole because of any one of a number of obstacles (e.g. water hazards, severe doglegs, etc.), the extra yardage of the approach shot will increase the Scratch rating while the Bogey rating will remain untouched.  This higher Scratch rating narrows the gap with the Bogey rating and decreases the gap thereby reducing the Slope.  Conversely, if forced lay-ups only affect the higher handicapper, both the Bogey rating and the Slope will increase.

Contributed by:  Jim Cowan, Director of Course Rating and Handicapping, Northern California Golf Association

Share Your Comment

Name:
Email:
Location:
URL:

Comment:

Remember my personal information
Notify me of follow-up comments?

Please enter the word you see in the image below: