The United States Golf Association, the governing body for golf in the United States and Canada, goes to elaborate lengths to ensure that handicaps for golfers are based on authentic standards. Every golfer who complies with the rules and submits scores for the requisite number of rounds is given a handicap, or -- more formally -- a handicap index. Based on the best 10 scores from your last 20 rounds, the handicap index is said to be a measure of your "potential ability." The handicap system is designed to enable people of different skill levels to use their handicap indexes to create a fair match, with the superior player giving the inferior player a sufficient number of strokes to make the contest an equitable one.
Adjusted Gross Scores
The USGA's handicapping standards require golfers to adjust scores by discounting particularly high scores on individual holes. For example, if your handicap is 9 or less, any score over a double bogey on a hole will be reduced to that number for posting purposes. Likewise, if your handicap is 10 to 19, your maximum score on any hole is 7. This preserves the validity of the potential ability of a golfer, since the high scores will be adjusted so they don't have a disproportionate effect on your score and thus on your handicap.
A key standard for handicapping purposes is the course rating, established by the USGA, for each golf course from which it accepts scores. This is done by an exacting rating system conducted by a team of USGA officials. They evaluate a course to determine the score that would be expected from a scratch golfer playing it. The USGA course rating takes into account many factors, including elevation changes, landing areas, the size of greens and the normal prevailing wind direction.
Another key standard for handicapping purposes is the slope rating. While the course rating refers to the score a scratch golfer would normally record, the slope rating refers to the relative difficulty of a course for a bogey golfer compared to the scratch golfer. To establish a slope rating, the USGA meticulously examines factors such as whether the landing areas are particularly narrow, whether hazards are especially likely to trip up bogey golfers, as opposed to scratch golfers, and so forth. Although some people think a high slope rating -- the average is 113 -- means a course is especially difficult, the slope rating only applies to bogey golfers. It's possible for a course rating to be relatively low and a slope rating to be relatively high.
The USGA uses a standard formula to figure out your handicap index. First it calculates your handicap differential by subtracting the course rating from your adjusted gross score. The difference is multiplied by 113 -- the standard slope rating -- and the product is divided by the course's slope rating. The result is rounded to the nearest tenth of a stroke.
To calculate your handicap index, the USGA establishes a handicap differential for each score you submit and then takes the best 10 of your most recent 20 scores, averages them, and reduces that figure by 4 percent.
The handicap index is converted to the course handicap based on the slope. Golf courses have a chart for each set of tees. Look up your index on the chart to see what your course handicap is.