The Artful Science Of The USGA Course Rating System


Golf-course raters from around the world sharpen their skills at the USGA’s annual calibration seminars to help ensure that every golfer’s Handicap Index translates fairly from course to course

By David Shefter, USGA

Phoenix – The numbers were barked out as if executed by a state-run lottery administrator.

45, 46, 11, 12, 27, 16.

However, this oratory wasn’t searching for the next millionaire, although the exercise taking place at the ninth green at Arizona Country Club on a glorious late-February morning could be construed as invaluable to anyone who plays golf.

The USGA's Eric Lahman, left, and Doug Sullivan go through the on-course rating exercise in Naples, Fla.

Five members of the USGA’s Course Rating Committee, along with two USGA staff members from the Handicap and Course Rating Department, are vigorously shouting numbers, letters and scribbling notes onto a course-rating sheet known as a Form 1. The dedication and passion is palpable:

“What were your three widths [for the green]?” asks veteran committeeman Warren Simmons, an Arizona C.C. member and former executive director of the Colorado Golf Association who was responsible for procuring the venue for this year’s Western Calibration Seminar.

“I’ve got 17 to the middle,” Simmons yells to the group standing at the green.

“Yep, 17,” confirms Eric Lahman. Lahman is the USGA’s assistant manager of Course Rating and Handicapping.

For another three hours, the group of seven surveyed every inch of the four holes to be used by the seminar attendees for the critical on-course rating exercise. One of two held annually in the U.S., the Western Calibration Seminar attracts some of the best course raters from authorized golf associations in this country and abroad. Each association is permitted to send up to four individuals, and they travel from as far away as Hawaii and Puerto Rico to participate in the two-day event. In March, another seminar was held in Naples, Fla. At that meeting, the USGA’s Course Rating Committee convened to discuss possible changes to the system. The ever-evolving USGA Course Rating System runs on a four-year cycle, just like the Rules of Golf.

The calibration seminar is not Course Rating 101. Neophyte raters need not apply. Attendees are expected to be well-versed in the USGA Course Rating System.

“This is the fourth one I’ve been to, and there’s no doubt about it, you learn something every time you come,” said 65-year-old Owen Osborne, a volunteer with the Oregon Golf Association who has been rating courses for seven years. “[The USGA staff and Course Rating Committee members] try to make it so there’s something unusual that you have to think about.”

The purpose of a calibration seminar is to get consistency. Consistency in course rating helps ensure that everyone’s USGA Handicap Index translates to any golf course, no matter where it’s located or if it’s private or public. Depending on the USGA Course Rating and Slope Rating of a particular golf course, a golfer’s Handicap Index will convert to a Course Handicap, which represents the number of strokes needed to play to the level of a scratch player – or the Course Rating of a particular set of tees. The purpose of having a Handicap Index is to make the game fair and equitable for everyone who plays.

That’s why in the late 1980s, after nearly 10 years of testing and analysis, the USGA added Slope Rating. Slope Rating is a ratio that represents how difficult a course will play for golfers of varying abilities in relation to a scratch golfer. Slope Rating takes into account certain aspects of a course’s layout that will affect a high-handicap player’s score more than that of a low handicapper. Calibration seminars began soon thereafter as a way to educate raters on the process.

Previously, courses were only given numbers based on what a scratch golfer should score. While that system worked well for many years, it had significant flaws and inconsistencies. A person’s Course Handicap at, for example, the Black Course at Bethpage State Park, has little to do with how that golfer will play at another local municipal course. Or as Simmons put it, a size 10 doesn’t necessarily fit every person who is a size 10. “Some are wide, some are regular and some are narrow,” he noted. “It’s the same with golf courses.”

Simmons should know. The former Air Force Academy mathematics instructor, who received his USGA Ike Grainger Award at the calibration seminar to commemorate 25 years of volunteer service to the organization, was part of the Handicap Research Team that came up with the sophisticated formulas that ultimately became the current USGA Course Rating System.

Despite the complex formulas used to rate courses, raters aren’t expected to be experts in mathematics. They don’t even have to be scratch players, though they should be familiar with the abilities of one. Computer programs crunch all the data to determine the final Course Rating and Slope Rating for a particular course.

One common myth about raters is that they determine the handicap stroke allocation numbers for each hole. In fact, those figures are done by each club, usually by reviewing scorecards of various levels of players, to determine which holes produce the largest spread in hole scores, and determining where strokes are most needed by players with higher handicaps vs. their opposition.

“We get that question all the time,” said Osborne.

Another fallacy is that the USGA’s Course Rating numbers are used to rank courses for golf publications. A rater doesn’t determine whether Bethpage Black should be ranked higher than Winged Foot Golf Club in a golf publication or guide’s pecking order.

“It’s become much more objective than subjective,” said Course Rating Committee member Doug Sullivan, a former USGA staff member who is now the director of course rating for the Southern California Golf Association. “It’s all about numbers and using the corresponding tables.”

The USGA Course Rating System manual provides a way to examine a golf course as a set of categories of obstacles, such as bunkers, water hazards, trees, fairway widths, rough heights, green targets and topography. Other attributes factor into those categories (i.e., roll, depth of bunkers, green speeds, mounding and prevailing winds), but the most critical component is yardage. Sullivan, who rates every course for the SCGA, will measure the golf course from the various tees a couple of weeks before bringing his rating team to the course.

“This is what we recommend,” said Scott Hovde, the USGA’s manager of course rating and handicap education, referring to measuring the tee-to-green yardages, and green depths and widths first before moving on to rating the obstacles. “Just getting the yardages for an 18-hole course can take a couple of hours.”

Attendees, like those above in Naples, Fla., this past March, are expected to be well-versed in the USGA Course Rating System.

For the calibration seminar, the committee members and two USGA staff members spend Sunday morning gathering vital information for the four holes to be used the following morning. They have chosen a loop that includes the par-5 third hole, the par-3 fourth and ninth holes and the par-4 fifth hole. All four have interesting obstacles, and, logistically, it’s the best routing for the attendees.

The seven individuals gather that evening in the Arizona C.C. board room to hash out the final figures. They determine their landing zones for the male and female scratch and bogey golfer. Simmons, Sheri Erskine from the Women’s Golf Association of Northern California and the Arizona Golf Association’s Lorraine Thies handle the female numbers along with Hovde. Sullivan, Lahman and John Saegner of the Washington State Golf Association tackle the men’s numbers.

Lively debate ensues as they go over everything from trees to bunkering to widths and green speeds. Once the final numbers are determined, some are given to the attendees to save time and standardize values that are not readily apparent, such as mid-season rough height and Stimpmeter reading. Certain facts are listed while the rest of the information must be obtained by careful measuring and observation.

During the committee’s discussion, letters emanate as if part of some bizarre verbal alphabet soup.

Do you have an I? What about a D for the bunker? Is there a Y? What are your R and R numbers? Do we need a B adjustment? What’s the W for that green? Don’t forget we have a Q there.

Each obstacle receives a final number between 0 and 10 (4 is considered average). Under the current system, that figure has a plus or minus error factor of one. Missing by one only equates to  one-100th of a stroke in the final Course and Slope Rating. That’s okay. But as the committee will see the next day, sometimes raters can be two, three or four points off. And that’s where potential problems can arise.

“There are several things that can trip you up,” said Osborne, who last year rated all three courses at Bandon Dunes in a five-day period. “One is hazards coming into play more than once on a hole, and a cumulative effect comes in. You get a number that’s high enough on successive shots, then you do an adjustment to make it even more difficult. That trips up a lot of people.”

Any time a course is officially rated, a minimum of three individuals comprise each team, with one person designated as the captain or team leader. Since the Oregon Golf Association only had two attendees – Osborne and Ron Clevenger – they are teamed with Brent Hathaway (Washington State Golf Association) and Richard Smith from the Saskatchewan (Canada) Golf Association. At this seminar, a group has also flown from Puerto Rico; it’s not unusual to see international associations in attendance. Though the USGA governs only in the U.S. and its territories and Mexico with regard to the Rules of Golf, its Handicap and Course Rating System has licensees from 55 international golf associations.

So on this Sunday morning, a combined 22 male and female teams hit the course. It looks like a small army of spectators as they wander down the third hole armed with clipboards, rating manuals and various measuring devices, from lasers to altimeters.

For the next few hours, the teams measure, step off and eyeball all the categorized obstacles for the chosen four holes. They check their appropriate tables in the Course Rating manual to establish the proper numbers for bunkers, water hazards, elevation, fairways, green targets, recovery and rough, out of bounds and extreme rough, trees and green surface. Teams also must adjust the normal landing zones for any effective playing length correction factors such as roll, elevation, dogleg/forced layup, prevailing wind and altitude. In addition, they must look for other key characteristics like the fraction of greenside bunker coverage. Between a quarter and a half is one number, but more than half is another figure.

Each rater is given a Form 1, which is a spread sheet containing boxes for each obstacle. Space is provided for notes in case any adjustments are required before assigning the final value. Once a hole is completed, the team gathers and discusses their numbers.

“There were two or three times where one of us said, ‘What about this?’ and it was a point that the rest of us hadn’t thought about,” said Osborne. “After you considered it, you either accepted it or moved on.

“The point you have to avoid is not arguing over stuff like minute details. That’s why we have a captain or team leader. When you get to the point, okay, that’s enough. Pick your number and move on.”

Following lunch, the groups reconvene – those rating for men in one room and those rating for women in another. The final numbers are collected by the USGA staff and tabulated and projected onto a screen to compare against the figures obtained by the committee.

This is when the fun begins.

Simmons asks a delegate from one association how she could be so off on her bunkering. Turns out the team had come up with the right ratio of bunkers around the green but simply had poor math translating it to a fraction. It draws a chuckle from the group, but it’s no laughing matter. Such errors could cause a course to be rated improperly.

Trees turned out to be a hot subject, especially for those who rate in areas such as northern California and the Pacific Northwest where the foliage tends to be dense. This particular course had tall palm trees that are not as difficult to recover from as oaks, evergreens or redwoods.

“We rate trees differently,” said Jerry White-Moreno of the Pacific Women’s Golf Association, which encompasses public courses in northern California. “[But] I have a whole list of things. We don’t normally stimp the greens to see if they are moderate. We eyeball them. Also percentages. My rating team, we don’t pace off the greens. It’s either a quarter, a half and what do you think. Those are things that are really going to change.”

And this is precisely the goal for these calibration seminars. This isn’t a competition, although some teams treat it as such. Even the committee members admit to learning a few new tricks. In the long run, education is the ultimate goal.

 “We have eight different divisions in our area,” adds White-Moreno of her association, which comprises some 250 courses and nearly 300 golf clubs. They also work with the Women’s Golf Association of Northern California, which has the region’s private clubs. “We need to come together [for more consistency]. We only rate six to eight courses a year and in my area, we maybe do five. We didn’t have any [formal] training. You had to follow the raters to try and pick it up and that was very difficult. A lot of time they didn’t have time to answer your questions. That’s why I would always ask for all of the tests. That’s how I picked up course rating.”

The seminar, which began with an individual test given to all attendees before their arrival, concludes with a team exam with four fictitious holes. One question involves water hazards and trees. Another deals with green target and recoverability and rough ratings. Another discusses bunkers and fairways. The exercise sparks healthy debate.

Then it’s time to depart for home. Many are mentally exhausted, but the bottom line is every course rater leaves the seminar better, well, calibrated than when they arrived 48 hours earlier.

David Shefter is a USGA Digital Media staff writer. E-mail him with questions or comments at


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