USGA Handicap System Definitions

The following are a listing of general definitions within the USGA Handicap System.
Handicap Index
A Handicap Index compares a player’s scoring ability to the scoring ability of a scratch golfer on a course of standard difficulty. A player posts scores along with the appropriate USGA Course Rating and Slope Rating to make up the scoring record. A Handicap Index is the USGA’s service mark used to indicate a measurement of a player’s potential ability on a course of standard playing difficulty. It reflects the player’s potential because it is based upon the best handicap differentials posted for a given number of rounds, ideally the best 10 of the last 20 rounds.
A Handicap Index is portable from course to course, as well as from one set of tees to another set of tees on the same course. A player converts a Handicap Index to a Course Handicap based on the Slope Rating of the tees played.
Course Handicap
A Course Handicap is the USGA’s mark that indicates the number of handicap strokes a player receives from a specific set of tees at the course being played to adjust the player’s scoring ability to the level of scratch or zero-handicap golf. A Course Handicap is determined by applying the player’s Handicap Index to a Course Handicap Table or Course Handicap Calculator.
Equitable Stroke Control (ESC)
Equitable Stroke Control (ESC) is the downward adjustment of individual hole scores for handicap purposes in order to make handicaps more representative of a player’s potential ability. ESC sets a maximum number that a player can post on any hole depending on the player’s Course Handicap. ESC is used only when a player’s actual or most likely score exceeds the player’s maximum number based on the following table:

Golf Club
A golf club is an organization of at least ten individual members that operates under bylaws with committees (especially a Handicap Committee) to supervise golf activities, provide peer review, and maintain the integrity of the USGA Handicap System. A golf club must be licensed by the USGA to utilize the USGA Handicap System. A club can obtain a license directly from the USGA or in conjunction with its membership in an authorized golf association that is already licensed by the USGA and that has jurisdiction in the geographic area that includes the principal location of the golf club.
A golf club is one of three (3) Types:

Type 1. The members of a Type 1 club are located at a single specific golf course with a valid USGA Course Rating and Slope Rating where a majority of the club’s events are played and where the club’s scoring records reside; or 
Type 2. The members of a Type 2 club are affiliated, or known to one another, via a business, fraternal, ethnic, or social organization. The majority of the club members had an affiliation prior to organizing the club; or 
Type 3. The members of a Type 3 club had no prior affiliation and a majority of the recruiting and sign up of the membership is done by solicitation to the public (e.g., newspaper, Internet). 

Handicap Committee
An essential element of the USGA Handicap System is the Handicap Committee. Each golf club or authorized golf association utilizing the USGA Handicap System must appoint a Handicap Committee that ensures compliance with the USGA Handicap System, including peer review. A majority of the Handicap Committee, including the chairperson, must be members of the club; club employees may serve on the Handicap Committee, but an employee may not serve as chairperson.
Duties of the appointed Handicap Committee include:

Communication with club members 
Maintenance of player records-correction of scoring records, assignment of modified handicaps 
Display of Course Ratings, Slope Ratings and Course Handicap tables 
Examining results of competitions 
Serve as the local club authority on the implementation of the USGA Handicap System 

Handicap Differential
A Handicap Differential is the difference between a player’s adjusted gross score and the USGA Course Rating of the course on which the score was made, multiplied by 113, then divided by the Slope Rating from the tees played and rounded to the nearest tenth, e.g., 12.8. The Handicap Differential is the official reflection of how well the round was played (lower the better) as it accounts for the players score in addition to the difficulty of the course and tee the score was record on (rating & slope values).
Peer Review
Peer review is the ability of golfers to gain an understanding of a player’s potential ability and to form a reasonable basis for supporting or disputing a score that has been posted.
There are two essential elements of peer review:

Members of a golf club must have a reasonable and regular opportunity to play together. 
Access must be provided to scoring records, as well as to a Handicap Index list, for inspection by others, including, but not limited to, fellow club members. 

Score Type
A score type indicates specific aspects of a score within a player’s scoring record and should be designated in the following manner:

H = Home

A = Away

T = Tournament

I = Internet posting

C = Combined Nine Hole Scores

P = Penalty Score