Class Performance Index relative to other ratings

In my previous post I discussed how advantage at a yearling or two year old sale can be found by looking specifically at offspring out of mares that have a CPI of 2.62 or better. Foals out of these mares represent an advantage over mares that have lesser race performance, all other things being equal. I also discussed how through the concept of missing heritability by specifically selecting for mares that could run themselves, we are hoping to diminish this effect that can influence prediction of outcomes. The Class Performance Index is a rating that has been developed by the Jockey Club Information Systems. It is not a widely use statistic as far as I can see, most likely because unlike the

How 'good' does a mare need to be as a race mare to produce a good horse?

In our last post we looked at a recent scientific study that detailed out the importance of the maternal line, in particular the race performance of the dam of a yearling in terms of its influence on the outcome of the resultant foal. Unsurprisingly, the study found that a good stallion could generally not negate the heredity effect of a poor race mare but that a good race mare could negate the hereditary effect of a poor sire. This finding is pretty much the same finding that pedigree statistician David Dink who has written extensively about it here, here and here, and a recent issue of Marketwatch where editor Ian Tapp tackled a similar concept looking at the production of race mares based

Potential role of maternal lineage in the thoroughbred breeding strategy

For some time now we have been of the opinion that there has been over selection of the paternal side of the pedigree and under selection of the maternal side of the pedigree in thoroughbred breeding. That is, with large books and better veterinary practice, the bar to become a stallion has probably moved up a little too high (you are just about required to be a GI winner now to have any chance) while because of the same quest for large stallion books, the bar for a mare to enter the breeding shed has slipped to the extraordinary low (basically two functional ovaries gets you in). We have done a lot of our own statistical research on this and found that there is a significant advantage in b

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