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About APEX Ratings

APEX Sire Ratings were developed at Racing Update 30 years ago and are essentially a better average-earnings index. APEX by the way stands for Annual Progeny Earnings IndeX. One key difference is this: the average-earnings index divides all earnings by a sire by the number of his runners in a year (or season, in the Southern Hemisphere) and divides the sire’s average earnings by the average earnings for all sires in that jurisdiction in that year; if the average earnings for all runners is say $15,000 and the average earnings per runner for the sire you’re querying in $15,000, his average-earnings index for that year is 1.00.
APEX establishes three class levels: A Runners (the top 2% of earners/runners); B Runners (the next 2%); C Runners (the next 4%); and therefore ABC Runners (the top 8%), then measures the frequency with which a sire gets runners in each of these categories and divides the sire’s percentage of, for example, A Runners by 2% (the percentage for all sires from all runners counted by APEX). In APEX ratings one huge earner can’t inflate a sire’s index rating like it does in the average-earnings index; it’s just another A Runner. Over horses’ careers, about 4% of named foals become A Runners in one or more seasons – about the same percentage of Group-Graded plus Listed winners.
There are two other key differences from a cumulative average-earnings index. First, we limit the data to the previous seven seasons (for the 2024 ratings: 2017-2023), which identifies sires who might have once been great but have fallen off. Second, we do not count all runners by all sires in our calculations. That method seems logical but in fact, when applied commercially, it tends to inflate sires’ ratings within the commercial population. We exclude all sires which average fewer than 10 foals/crop as having no impact in the thoroughbred commercial world. This eliminates about a third of sires and 20% of foals but results in index figures which have a more accurate commercial application than the ‘purer’ all sires/all runners method. Our method is absolutely just as logically sound – and much more accurate when applied commercially. We also do not assign APEX ratings until sires have 3yo’s; the numbers for freshman sires just prove to be too dodgy.
One thing APEX ratings have in common with average-earnings indexes is they are calculated for one runner every year/season it races, up to seven in APEX. So a horse who races in two different years is two Runners, etc., and the same for A, B, and C Runners; Winx, for example counted as six A Runners for Street Cry, because she reached the respective A Runner earnings thresholds in six separate seasons. There are a total of 17 different APEX ratings: A, B, and C Runners in each of three Northern Hemisphere Regions (North America, Europe, Japan), so that’s nine indexes; A, B, C, and ABC runners in the three regions combined, which is four more indexes; and ‘age indexes’ for ABC Runners as 2yo’s, 3yo’s, 4yo’s and 5yo’s and up. This enables us to chart sires’ typical progression at different ages: Sea The Stars, for example, has ABC Age Ratings of: 2yo-0.61; 3yo-1.67; 4yo-2.04; 5yo+ 2.38. So you know when you breed to or buy one by Sea The Stars it is less likely to be a smart 2yo compared to, say, his half-brother Galileo (2yo-2.79).


A RUNNERStop 2% 
B RUNNERSnext 2% 
C RUNNERSnext 4% 
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