Issues to be considered in determining hole index ratings


 

Golf clubs are required ‘to publish a table indicating the order of holes at which handicap strokes are to be given or received’ (Rule 33-4). But the Rules provide no method by which this order, or hole index rating, is to be determined. Golf Australia does provide helpful direction (‘Course Management, Marking the Course, & Course Set-up Procedures — Golf Australia Recommendations’, www.golf.org.au/site/_content/document/00014129-source.pdf). However, this is only advisory, and there are some matters canvassed which committees may wish to debate. Moreover, the widespread availability of hole-by-hole scores from computerised handicapping systems has made analysis of score data easier than in the past, and this may affect decisions on index determination. And availability of appropriate software* allows committees to explore a number of methods before determining on a preferred one. But committees should base their decisions on specific principles so that next time a revision is necessary, the ‘current’ committee can use these previously agreed principles or agree why it is changing to new principle/s.

A club committee needs to consider a number of issues in deciding how to determine hole index ratings. The following are noted as requiring consideration, not necessarily in order of importance.

  1. Should the same indexes be used for match play and stroke play?
  2. What should be the basis of determining hole indexes?
  3. For stroke indexes, if they are based on hole difficulties, how should these difficulties be defined?
  4. Should the same index be used for all ranges of handicap on a hole?
  5. What scores should be used to calculate hole difficulties?
  6. Should indexes be ‘balanced’ across nines?

Each of these issues is addressed below, and recommended principles are made in relation to them.

Indexes for match play and stroke play

The purpose of a golf handicap is to ensure equity when players are in handicap competitions, whether the competition is an individual match or stroke play. For stroke play competitions Golf Australia defines equity as all players having similar chances of winning or placing well in a competition (GA Handicap System). There is no equivalent statement for handicap match play; however, equity in such an event is that opponents should have about the same chance of winning a match.

How does this relate to hole indexes? In stroke play, players should receive shots at holes they find most difficult, so such indexes are normally based on perceived hole difficulty. For match play, there are two competing principles: a player should not be substantially advantaged (a) because of when in the round s/he receives a stroke, and (b) by receiving a stroke at a hole which both players find equally difficult. These two principles lead to the two methods of assigning indexes for match play: apply a place-in-the-round distribution, and use a hole difficulty measure.

The first principle could lead to a player in a match receiving a stroke on the easiest hole on the course but not receiving one on the most difficult. The second principle could lead to a match being completed as a result of not receiving a critical stroke until too late in the round.

Although GA recommends application of the first principle for handicap match play, a comment refers to a potential problem.

When using the match play index in match play competitions, the index should be adapted when a match commences at any other hole on the course other than the 1st: Hole 1 in the recommendation should apply to the first hole to be played, Hole 2 to the second hole to be played, etc.

 

Thus, if a club publishes a separate match play index, it ought note that this index should be reversed if the match commences on the 10th. This is a potential source of confusion (and dispute) for players, and would be better if it could be avoided.

Which of the two principles is the more equitable? This requires a subjective judgement, but most people consider the second principle is the more equitable: match play hole indexes should be based on hole difficulties. Thus, both match play and stroke indexes can be based on the same principle, and there is no need to publish two separate indexes.

Principle 1. Match play and stroke play hole indexes should be the same and based on hole difficulty.

Method of determining hole difficulty

There are many ways of determining hole difficulty, such as counting the number of birdies, calculating mean Stableford scores, calculating mean gross scores, etc. Some of these have been used previously because they simplified data entry and analysis processes. But hole-by-hole gross scores are now readily available from computerised handicapping systems, and the number of scores to be treated is virtually immaterial.

A question which is often asked is, Should the same method be applied for par 3s, 4s and 5s? A good approach is to look at the difference between the mean score and par on each hole as that is independent of the par. A more difficult hole will have a higher mean difference from par, and holes can therefore be ranked in order of mean differences. Moreover, mean gross scores are independent of the current hole indexes (which is what is being determined), so they are better than mean net scores. Also, the difference of mean gross score from par is likely to be more stable than, say, number of birdies.

Principle 2. Hole difficulty should be based on difference between mean gross score and hole par.

Use of the same index for all handicap ranges

Many clubs show only one set of indexes on their cards (1–18). This is based on an assumption that all golfers, regardless of handicap, find the order of difficulty of holes the same. This is generally not the case: lower handicap golfers find par 5s relatively easy and par 3s relatively more difficult, whereas higher handicap golfers find the reverse.

If the assumption is not correct then allowance should be made by providing indexes appropriate to each range. For men, that is Plus, 1–18, 19–36; for women, the same, and 37–45. For Plus handicaps, there would be little call for indexes lower than +6.

Principle 3. Separate hole indexes should be provided for different handicap ranges: Plus, 1–18, 19–36 and, for women, 37–45.

Scores to be used for hole indexes

Scores from singles stroke play should be used for stroke indexes. Moreover, clubs normally wish to indicate the indexes for their members’ ‘medal’ tee positions. Therefore, scores from the same back members’ tee positions only should be used, from throughout the year to allow for different course conditions. Scores from monthly medals and any ‘Board’ events, and other events conducted by the club involving outsiders playing from the ‘medal’ tees, should also be used.

There is a preference for Stroke events, as these will produce the most accurate measure of hole difficulty, but inclusion of Stableford and even Par events doesn’t affect the order of hole difficulty markedly, so they may be used if there is insufficient Stroke data.

Principle 4. Scores for singles stroke play events played throughout the year from the members’ back markers should be used for determining hole indexes.

Balancing of indexes across nines

There are three main reasons why hole indexes should be ‘balanced’ across the nines.

  1. Match play competitions. If the stroke index is used for match play competitions then it would be unfair if, say, one player has to give another 5 strokes, and they were all on one nine. If they were all on the second nine, the lower marker would have a good chance of being so many up by the time these holes were reached, it would be difficult for the other player to retrieve the situation. Alternatively, if they were all on the first nine, the higher marker might have the same possible advantage.
  2. Countbacks. Most clubs resolve ties by using the Australian countback system, which considers scores on the last nine, irrespective of the order in which the nines were played. If there is a preponderance of lower index holes on the front nine this is to the advantage of higher markers as lower markers would be less likely to have higher net scores on the last nine. And the converse applies if there is a preponderance of lower index holes on the back nine.
  3. Nine hole competitions. The Australian Handicapping System now allows for ‘storing’ of nine hole scores which may later be combined to create a handicap 18 hole score. If one of the nines had many more lower index holes, this might lead to a handicap distortion if players tended only to play one nine or the other.

Principle 5. In the interests of fairness, hole indexes should be reasonably balanced across nines.

There are other issues which should be considered, but these constitute a major set which committees need to take into account when determining hole index ratings.

 

Article by Murray Cropley, Hexadec Services. 

 

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