Horse indices : Show-jumping, Eventing, and dressage

Performance indices are published for each year that a horse takes part in competitions, they are called :

• ISO for show-jumping
• IDR for dressage
• ICC for eventing

Competition classes taken into account

For a given year, a performance index is calculated based on the competition results from the first weekend of october in year N-1, through to the last weekend of september in year N.

Are taken into account all affiliated classes run in France, on both amateur and professional circuits supported by the FFE  by the SHF. However some results are not taken into account :

• Hunter classes for show-jumping
• Rankings in young horse championships which combine the class result with a conformation/style mark (these are already integrated)
• Team rankings in team competitions, when the team result is calculated on individual results (e.g team competition in eventing)
• Classes open to more than 3 categories of rider, or categories which are more than one level apart.

Note concerning international competitions

The performance of horse/rider combinations competing for France in international copetitions have always been taken into account in the calculation of indices.

Since 2007, French horses competing internationally with a foreign rider, are also taen into account. This is important for French breeders, as it promotes the stallions, and kindred of exported performers. While waiting for automatic transfer of these results from the  FEI  via the FFE, the Selle-Français Stud-book transfers the results of French horses competing under foreign colours. However the only results taken into consideration exhaustively are the results of horses competing at least in 3* competitons, and at least in 1m40 classes for show-jumping.

Criteria used for measuring performance

In all three disciplines, the method for calculating performance has evolved since indices were first established :

Repeatability for the ranking criteria between two classes is 0,29 for show-jumping, 0,35 for dressage, and 0,33 for eventing.

Accuracy coefficient

Since 1997, performance indices have been accompanied by an accuracy coefficient (noted CP in French). This coefficient (CP) depends on the number of classes run, but also :

• On the number of starters for each class : the higher the number, the higher the coefficient.
• The horse’s placing : a horse placed in the prize ranking, has a higher coefficient than a horse not placed.
• Homogenous competition : the closer level of all the horses in a same class, the higher the coefficient.

The accuracy coefficient is mentioned in brackets after the index. The value is situated between 0 and 1, and depends on the quantity and quality of information available for each pony. The closer it is to 1, the more accurate it is (the higher the number of classes and participants)

Reference markers for the accuracy coefficient in equestrian sports

    • < 0,60 : index not significant
    • between 0,60 and 0,80 : index quite significant
    • ≥ 0,80 : index very significant

If the value of the coefficient is too low, the index is not significant. The information available for the particular horse is too scarce to calculate a significant index.

Points of reference

The average is represented as index 100. The distribution curve is symetrical around the average : 50 % of horses competing will therefore obtain an index of above 100 per year.

It should also be noted :

• Every year around 12 % of the horses who are given an index (horses competing) reach or go above a 120 index (« good horses »)
• Every year around 1 to 2 % of horses competing are attributed an index of 140 or over (« very good horses »)

Thus, the difference between two indices is explained by the regularity of results, the number of competitions taken part in, the level of the classes taken part in, as well as the other competitors in those classes.

Average index and headcount

In order to situate the level of one’s horse, and to obtain elements of comparison with the other horses competed against, the average index of a horse’s direct competition can be calculated. This is the indicator given under the heading « average level of competition ». For each horse with an index for each year, this gives :

• The average index, i.e the average of the performance indices of the other horses competed against.
• The headcount which corresponds to the number of different horses which the horse in question competed against during his participations.

Example n°1

For a horse with a performance index of 120, when the average level of other horses competed against is 140. The horse competed against 356 other horses. This means that in the type of class this particular horse competed in, he was less successful than the 356 other horses taking part inthe same classes.

Example n°2

For a horse with an index of 120, whereas the average indice of the horses he competed against is 100, This means that the for type of class competed in, he was far more successful than the other horses in the same classes.

Example n°3

For a horse with an index of 120, with the average for the other horse competed against is also 120. This means that the in the type of class competed in, the horse was on average as successful as the other horses in the same classes.

The genetic index is named :

• BSO for Show-jumping
• BCC for Eventing
• BDR for Dressage

A coefficient of determination  (CD) is atributed to each index, this measures the accuracy of the genetic estimation for the horse.

Information and genetic parameters used

All of the horse’s results throughout its career, and not only the best performance index,  are taken into account for the calculation of the genetic index. To calculate the genetic index (BLUP), all the performances of the horse’s kindred (in the ascending or descending lines) are also taken into account. It is therefore possible to calculate the BLUP of a foal before he’s even conceived.

• Blup foal = (Blup sire + Blup Dam) / 2
• CD foal = (CD Sire + CD Dam) / 4

Coefficient of determination

The CD measures the accuracy of the genetic estimation value. It varies between 0 and 1. This coefficient will evolve depending on the number of performances of the horse (number of classes competed in, number of years) and the type of related kin having had performances. It is only the knowledge of the descending line which allows to reach a CD close to 1. The CD is situated on the scale, according to the available information :

• Between 0 and 0,4 if the only known information concerns the ascending line
• Between 0,12 and 0,65 if the ascending line, and their performances are known.
• Between 0,12 and 0,72 if the ascending line, their performances, and some progeny are known.
• Between 0,12 and 1 if the ascending line, their performances, and numerous progeny are known

The CD also depends on genetic parameters (heritability, repeatability). It takes 10  years, or 10 of the  progeny to be competing in the discipline of eventing to reach the same level of accuracy (0,27) , as with one year of a horse’s own performances in show-jumping.

Note : Publication of the BSO, BCC, and BDR

Whenever there is an ancestor with a performance index (ISO , ICC, or IDR)  in a lineage, This automatically gives rise to a genetic index (BSO, BCC, or BDR)  for all the descendants. It is therefore not uncommon for race horses or ponies to have a BSO, BCC, or BDR, but in these cases the CD will be very low. The indices in these cases are not significant. Please note, for ponies, even with a high CD, it is only the performances on the « horse » circuits which are taken into account for the BSO, BCC, or BDR calculation.
In the Olympic disciplines, only the indices with a DC of over 0,20 are published.

Points of reference

A horse with a positive index is statistically considered to be an improver for the ability considered, whatever his age.

Breeders selecting according to ability, the population will improve. Consequently , the average level of the population also improves. So as to keep the same points of reference (positive index versus negative index, or threshold of the top 2 % corresponding to an index of +20), indexes are calculated on a mobile basis, i.e « 0 » corresponds to a reference population.

This reference population is :

• For Show-jumping, the group of 5 year old horses before the year of calculation (best age for selection), with a CD ≥ 0,22, meaning births in 2013, for indexation in 2018.
• For Dressage, the group of SF and AA horses aged between 4 and 7 years old, where the average CD is equal to 0,34 (i.e the accuracy obtained after a year’s performance). Thus, the population concerned by dressage is fairly well determined.
• For eventing horses, the group of SF and AA horses aged between 4 and 7 years old, with a minimum CD of 0,14.

Using the genetic index

Genetic indices are one of the best tools when deciding on suitable matings with a view to producing « sport » horses. It is the best estimation of the quality of a genitor, according to available information.
But it is not always easy to compare stallions of different ages, with consequently indices with a very different accuracy (CD of 0,35 if only the parentage is known, up to 0,98 if there are already numerous descendants tested in competitions). For Show-jumping and Dressage, two tools have been developed to make this comparison easier :

• Genetic ranking
• Value betting

These tools are based on the idea of confidence interval

Indexes are available for free on the internet site www.ifce.fr
Section SIRE, then procedures, then «Info chevaux », to directly access the page of horse or pony. Click on « aptitude »