The USGA Handicap System™ was updated this year for the next four-year cycle (2012-2015). One new decision in the System relates to clarifying the phrase “principles of the Rules of Golf, Decision 4-2/1.” The USGA Handicap System provides some flexibility in posting scores for handicap purposes in part due to a substantial scoring record and history of rounds that is built up by each player (ideally 20 posted rounds) and, in general, the better half average of those performances (Handicap Differential™) are utilized to calculate a Handicap Index®.
While the USGA Handicap System strives to be congruent with the policies of the Rules of Golf, there are some situations where a player has played a hole in such a manner that the score would be sufficiently accurate to be used for handicap computation purposes. Occasionally, holes are not played strictly in accordance with the Rules of Golf.
The motivation behind this decision is to ascertain a player's potential ability by attempting to capture as many scores as possible for handicap purposes, rather than just those made in strict accordance with the Rules of Golf. The USGA has found that due to many fun formats conducted by clubs, match-play events, four-ball, etc. there may simply be too few scores posted to gauge every player’s potential ability sufficiently.
For example, a player starting but not finishing a hole in stroke play (e.g., picking up before holing out) records the "most likely score" for handicap purposes (see “Section 4-1”). This policy also includes situations that are generally out of the player's control, such as incorrectly installed hole liners or an incorrectly marked golf course. (See “Section 15-5.”)
You may ask, “What if a player is using this information to manipulate a Handicap Index?” Ultimately the Handicap Index issued to the player is vouched for by that licensed golf club’s Handicap Committee; this is in addition to the peer review being performed on each player’s scoring record. If a player’s Handicap Index doesn’t represent its potential ability the Handicap Committee can take action under “Section 8” of the System.
Also keep in mind that a player must play at least seven holes under the principles to post a nine-hole score and 13 to post an 18-hole score (see “Section 5-1”).