A Head For Ratings
Everybody has a nemesis hole. It's the one that tends to ruin a
good round, with an obstacle that you just can't figure out how to avoid.
It's psychological. And, believe it or not, it's addressed in the USGA Course Rating
While the system is a complex set of rules and computations, it boils down to three
numbers given for each set of tees: the course, bogey and slope ratings. Most people
know that the course rating is a gauge of difficulty for a scratch player. After
the Handicapping 101 from last September, more people should understand the role
of a bogey rating.
Slope ratings are mathematical derivations of the course and bogey ratings and indicate
the measurement of the relative difficulty of a course for those who are not scratch
players. But how does a rating team determine course and bogey ratings?
First, yardage is an essential component. For all golfers, regardless of ability,
yardage is the most significant factor to overcome. Rating teams begin by measuring
the precise length of each hole. They then take into account several effective playing
length factors: How far does the ball roll? Are there any changes in elevation?
Are there any forced lay-ups or doglegs? Is there any prevailing wind or is the
course 2,000 feet above sea level or higher? Each of these would affect a course's
playing length and require an adjustment to the measured length.
But rating teams also pay close attention to a course's characteristics, called
obstacle factors, that can make each hole more difficult or easier. These represent
the most important assessments made by a rating team. Beginning in 1982, the USGA
introduced 10 factors that were considered crucial to course evaluation. Each of
these obstacle factors is rated on a scale of 0 to 10, depending on their relation
to how a scratch and bogey golfer would play the hole.
When the evaluation is complete, the numbers for each factor are totaled and multiplied
by a relative weight factor. The weighted obstacle values are applied to scratch
and bogey formulas, then converted to strokes. Those strokes are added or subtracted
from the yardage rating to produce course and bogey ratings.
There are several detailed factors to consider before a state, regional or local
golf association provides certified ratings to a club. There is little guesswork
involved; the process is objective and complete, with rating calibration seminars
held around the country on a regular basis.
The personal computer has made calculations within the system a much simpler process,
using software developed by the USGA. That's much easier than in the earliest days
of the system. Back then the raters found that crunching the numbers, like the inability
of some players to conquer a nemesis hole, was all in their heads.