Rule 4 — Clubs
The preamble to Rule 4 and Appendix II provides that:
A player in doubt as to the conformity of a club should consult the USGA.
A manufacturer should submit to the USGA a sample of a club to be manufactured for a ruling as to whether the club conforms with the Rules. The sample becomes the property of the USGA for reference purposes. If a manufacturer fails to submit a sample or, having submitted a sample, fails to await a ruling before manufacturing and/or marketing the club, the manufacturer assumes the risk of a ruling that the club does not conform with the Rules.
The vast majority of people who play golf assume that when they buy golf clubs, they conform with the Rules. To help prevent non-conforming equipment from appearing in the marketplace, the USGA offers an equipment testing and evaluation service to manufacturers, and encourages manufacturers to submit drawings, descriptions, and/or prototype samples of new product to the USGA as early in the development process as possible, prior to mass production and distribution, in order to avoid potentially costly consequences should the USGA determine that the product does not conform to the Rules of Golf. Additionally, this process helps to protect golfers from unwittingly obtaining non-conforming equipment for use under the Rules of Golf. While this procedure works most of the time, there are occasions when non-conforming equipment is sold in the marketplace. That, combined with the fact that many golfers like to make their own modifications to clubs (see section below on Wear and Alteration), makes the Guide an important tool for all concerned.
Form and Make of Clubs — General (Rule 4-1a)
Rule 4-1a provides that:
The player’s clubs must conform with this Rule and the provisions, specifications and interpretations set forth in Appendix II.
As previously noted, while the USGA’s equipment testing and evaluation process works most of the time in preventing non-conforming equipment from entering the marketplace, not all products are submitted to the USGA and some are submitted after they have been mass produced and distributed for sale. Additionally, on very rare occasion, a new or modified Rule can render existing equipment non-conforming.
As a result, it is the player’s responsibility to ensure that his clubs conform to the Rules. The player may consult the USGA, their Rules Committee or the Committee in charge of a competition in which he has entered for assistance in making this assessment.
Wear and Alteration (Rule 4-1b)
Over time, the face and grip of a club, in particular, may become worn through use. For example, a grip may become so worn that it becomes molded for the hands, or the grooves on an iron club may become so worn that they no longer conform to the requirements in Appendix II, 5c.
Rule 4-1b provides that:
A club that conforms with the Rules when new is deemed to conform after wear through normal use. Any part of a club that has been purposely altered is regarded as new and must, in its altered stated, conform with the Rules.
This means that a club which conformed when new cannot be rendered non-conforming due to wear through normal use. However, a club which did not conform to the Rules when new cannot be worn into a conforming state. Such a club would always be considered non-conforming. Wear is defined as the erosion of material. Damage, on the other hand, is usually caused by a single occurrence. Generally, material decomposition or deterioration is not considered wear.
Playing Characteristics Changed (Rule 4-2a)
Rule 4-2a provides that:
During a stipulated round, the playing characteristics of a club must not be purposely changed by adjustment or by any other means.
The purpose of this Rule is to prevent the player from purposely modifying his club during the round, such as modifying a club’s lie or loft, adjusting weight or changing the head and/or shaft, regardless of whether the club has been designed to be adjustable.
Foreign Material (Rule 4-2b)
Rule 4-2b provides that:
Foreign material must not be applied to the club face for the purpose of influencing the movement of the ball.
The Equipment Standards Committee employs this Rule when materials of a temporary nature have been applied to the face — such as saliva, grass juice, chalk, aerosol spray or similar substances. Permanent attachments or coatings such as plasma spray, “balata”-type rubber or even paint are dealt with under the club face Rules in Appendix II (see Section 5).
The most important question to ask when ruling on a club which has had something temporarily applied to the face by a player is “why has it been put there?” If a material or substance has been applied to the face in order to protect it or to clean it, then it would probably be permitted provided all other Rules are satisfied. However, if the purpose of the application is to influence the movement of the ball or to assist the player in making a stroke, it would be prohibited. Any type of tape or similar material added to the face is not permitted for any purpose.