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Newsletter - Issue 30 Date 08/06/07
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Course Ratings, Slope Ratings, Par, Definitions
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While playing golf Sunday with a friend, Lin Jursted,
he mentioned an interesting fact to me - that par is
the number that the average golfer passes on the 13th
hole on the way to a much higher score.
After hearing that, I decided to do a little research
on Par, Course Ratings, and Slope Ratings, and pass it
along...so here is the Course Rating Primer which I
found on the USGA website, it's a bit lengthy but I
think you'll find the information to be enlightening, enjoy!
Course Rating™ Primer
The USGA Course Rating System™ is the standard upon which
the USGA Handicap System™ is built. It affects all golfers
in the calculation of a Handicap Index®. Players “play to
their handicaps,” when their net scores (gross score—
handicap strokes) equal the USGA Course Rating™.
The USGA Course Rating System takes into account the factors
that affect the playing difficulty of a golf course.
Course rating teams from authorized golf associations
carry out the on-course portion of the rating process.
Authorized golf associations review the work of the teams
and then issue ratings.
Accuracy and consistency are the keys to effective course
rating. A course must first be accurately measured. The
measured yardage must then be corrected for the effective
playing length. These effective playing length corrections
are roll, elevation, dogleg/forced lay-up, prevailing wind,
and altitude. Obstacles that affect playing difficulty
must then be evaluated in accordance with established
standards. These standards increase objectivity in course rating.
Important Definitions
The following are terms essential to the USGA Course
Rating System:
Scratch Golfer: A male scratch golfer is a player who can
play to a Course Handicap of zero on any and all rated golf
courses. A male scratch golfer, for rating purposes, can hit
tee shots an average of 250 yards and can reach a 470-yard
hole in two shots at sea level.
A female scratch golfer is a player who can play to a Course
Handicap of zero on any and all rated golf courses. A female
scratch golfer, for rating purposes, can hit tee shots an
average of 210 yards and can reach a 400-yard hole in two
shots at sea level.
USGACourse Rating: A USGA Course Rating is the evaluation
of the playing difficulty of a course for scratch golfers
under normal course and weather conditions. It is expressed
as the number of strokes taken to one decimal place (72.5),
and is based on yardage and other obstacles to the extent
that they affect the scoring difficulty of the scratch golfer.
Bogey Golfer: A male bogey golfer is a player who has a
Course Handicap™ of approximately 20 on a course of standard
difficulty. He can hit tee shots an average of 200 yards and
can reach a 370-yard hole in two shots at sea level.
A female bogey golfer is a player who has a Course Handicap
of approximately 24 on a course of standard difficulty.
She can hit tee shots an average of 150 yards and can reach
a 280-yard hole in two shots at sea level.
Bogey Rating™: A Bogey Rating is the evaluation of the
playing difficulty of a course for bogey golfers under normal
course and weather conditions. It is expressed as the number
of strokes taken to one decimal place (92.1), and is based
on yardage and other obstacles to the extent that they affect
the scoring difficulty of the bogey golfer.
Slope Rating®: A Slope Rating is the USGA® mark that indicates
the measurement of the relative playing difficulty of a course
for players who are not scratch golfers, compared to scratch
golfers. It is computed from the difference between the
Bogey Rating and the USGA Course Rating times a constant
factor and is expressed as a whole number from 55 to 155. The
higher the rating, the more difficult the course.
A golf course of standard playing difficulty has a slope rating of
113.
The Rating Process
The rating process requires a study of each hole, including
detailed data obtained at all landing zones for both the
scratch and the bogey golfer. The rating teams use the
average shot lengths for both scratch and bogey golfers
to determine the landing zones. Length corrections and
obstacle values are considered at each landing zone.
Effective Playing Length Factors
The following correction factors are evaluated to determine
if the hole is effectively longer or shorter than the
actual measured length:
Roll: Roll is an evaluation of how far the tee shots for
scratch and bogey golfers roll, and the effect that has
on the playing length of the course.
Elevation: Elevation is a measure of how changes in
elevation from tee to green affect the playing length of a hole.
Dogleg/ Forced Lay-Up: Dogleg/forced lay-up is a measure
of how much longer or shorter a hole is played because it
has a bend (allowing players to cut the corner or forcing
them to lay up), or because it has obstacles, such as water
or deep bunkers, crossing the fairway in the players’
landing zones (which force the scratch or bogey golfer
to hit less than a full shot).
Prevailing Wind: Prevailing wind is a measure of the
effect of constant wind on seaside courses, plains courses,
or other courses unprotected from the wind.
Altitude: Altitude is an evaluation for courses at 2,000
feet or more altitude that will play shorter than their
measured length because shots fly farther in the thin air.
Obstacle Factors
The following obstacle factors are determined for each
landing zone for both the scratch and the bogey golfer:
Topography: Topography is a factor if the stance or lie
in the landing zone is affected by slopes or mounds, or
the shot to the green is uphill or downhill, making
club selection more difficult.
Fairway: Fairway is an evaluation of the difficulty of
keeping the ball in play from tee to green. Fairway ratings
are based on fairway width in all landing zones, hole length,
and nearby trees, hazards, and punitive rough.
Green Target: Green Target is an evaluation of the
difficulty of hitting the green with the approach shot.
Primary considerations are target size, length of shot,
how well the green holds, and the difficulty of normal
hole locations.
Recoverability and Rough: Recoverability and Rough is
the evaluation of the probability of missing the tee shot
landing zone and the green, and the difficulty of recovering
if either, or both, is missed. The Green Target rating drives
the Recoverability and Rough rating value.
Bunkers: Bunkers is the evaluation of their proximity to
target areas and the difficulty of recovery from them. The
Green Target rating also drives the Bunkers rating value.
Out of Bounds/ExtremeRough: OB/Extreme Rough is the evaluation
of the distance from the center of the landing zone to the
OB/Extreme Rough. High grass, heavy underbrush in trees,
and other extreme conditions are rated in this category
because a ball in such “extreme rough” is likely to be lost
or virtually unplayable. Such areas may also be rated under
Recoverability and Rough.
Water Hazards: Water Hazards is the evaluation of a water
hazard and its distance from the landing zone or green and,
in the case of a hazard crossing a hole, the problem involved
in playing over the hazard. The Water Hazards rating is
applied on any hole where there is a water hazard or lateral
water hazard.
Trees: Trees is the evaluation of the size and density of
the trees, their distance from the center of the landing zone
or green, the length of the shot to that target, and the
difficulty of recovery.
Green Surface: Green Surface is the evaluation of a green’s
difficulty from a putting standpoint. Green speed and surface
contouring are the main factors. The size of the green is
considered irrelevant in evaluating putting difficulty. A
Stimpmeter is utilized to measure the speed of the greens
based on midseason conditions.
Psychological: Psychological is the evaluation of the
cumulative effect of the other obstacles. The location of
many punitive obstacles close to a target area creates
uneasiness in the mind of the player and thus affects his or
her score. This value is purely mathematical and is added
after the on-course rating is complete.
Each obstacle is assigned a value of 0 to 10, depending on
its relation to how a scratch or bogey golfer would play the
hole. When the evaluation is complete, the numbers for each
hole’s obstacles are totaled and multiplied by a relative
weighting factor. The weighted obstacle stroke values are
applied to scratch and bogey formulas and then converted to
strokes. Those strokes are added or subtracted from the
Yardage Rating to produce a Bogey Rating and USGA Course Rating.
Courses must be re-rated at least every 10 years, or if
it is a new golf course, every 3 years for the first 10 years.
A course must also be re-rated if significant changes have
been made to the course. To schedule a course rating, the
club representative needs to contact its authorized
golf association.