Ratings are an assessment of the best ability of a horse, as shown on the track. Ability is inborn – you have what you’re given by your parents, no more, no less. Maturity, good training, sensible feeding – those are factors that bring out a horse’s inherent ability, but they won’t be able to improve on it. You either have it, or you don’t.
In the two tables for colts and fillies, the percentages on the topline show the distribution across all bins for the racing population as a whole.
An analysis of Graded winners shows that the second highest rating bin (90 upwards) is a minimum requirement for Gr1 and Gr2 winners, and to a large degree also Gr3 winners (the latter category features many handicaps, where lowly rated horses are able to beat the better ones).
Taking the male offspring (see table for colts), 2% falls in the top-bin (>99), 5% in the second highest bin (90-99), which together make for 7%. If the 13% from third highest bin (80-89) is added (the minimum for Listed and multiple winners) the combined rounded off total gets to 19%.
Looking at the bottom bin (<59, the likely non-winners), the population average is a scary 32% – one in three.
In the table, the six bins are shown together with two columns which add the two top-bins (AR>89, black type candidates), and three top-bins (AR>79, useful winners). Also added is the total number of rated horses (by sex), from which the bin percentages are calculated – the larger the number, the more reliable the percentages.
All this represents what can be expected, on average, from the colts produced by the sires in the table. The top-bins as well as the bottom ones help construct an informative picture. The bin-ratings for fillies (see table for fillies) are on a lower level than the colts, by 5 pounds (it equates the sex allowance).
Ratings used here are Ability Ratings (AR) representing career-best performances of horses, from races in South Africa only. Ability Ratings (AR) have been in use for South African racecourse performances since 1985. They are produced by the publishers of Sires 2018, and are routinely used in the daily races published in Sporting Post.
The methodology and scale of Ability Ratings (AR) are directly comparable to those published in the UK by Timeform (TFR) and Racing Post (RPR). The AR, like TFR and RPR, is expressed in pounds, rather than half kilos as is the norm with the official MR ratings published in South Africa by the NHA (formerly known as the Jockey Club). More on the subject can be found at www.sportingpost.co.za/racings-secrets-revealed