PRI: Linking Pedigree to Racing Performance

The study of pedigrees is a wonderful way of getting close to the greatest race horses in history. However, how can we link that knowledge to the goal of breeding a superior race horse? Superior is defined by the ability to win races and earn stake money to pay its way. We need to be able to relate pedigree with racing performance. The Sales Catalogs do this to a degree, but these documents are selling an outcome based on racing performance X racing performance. These characteristics  may or may not be necessarily linked. What we need to look at is an outcome showing racing performance linked to pedigree X racing performance…

John Henry: Rated 23rd in America’s top 100 racehorses of the 20th Century

PRI: Developing a System 

We have been developing a system which will better link racing performance to pedigree termed PRI (Pedigree Racing Index). This involves measuring the compatibility of stallions in the first four generations and applying statistical methods to come up with a % figure which is related to the probability of the horse being a superior race horse. We can then relate this number to the library of PRI scores for many horses built up over the years. The PRI scores in the library range from 100 to 43.3. Only two horses has received 100. One horse won at 10 of 12 starts and earned $3.88m

Have I found PRI helpful?

Does it work? The evidence I can show using PRI measured by linking pedigrees with racing ability is the result of my breeding program over the last 15 years. My mares cost between $250 and $11,000.

In comparison with the above, I have raced 11 horses with other owners. Nine of these horses were winners and their average earnings were $26,722.

Can PRI be useful?

Is the PRI analysis foolproof? Certainly not. It sometimes gives results that are not easy to explain. Racing performance linked to pedigree is still a very useful tool as the following will demonstrate. At the yearling sales a few years ago a friend of mine bred a horse by Encosta De Lago and it made $250,000. The horse was well conformed and looked very powerful. I had already given this horse a PRI of 47.3 and believed it would probably never win a race.

However, I didn’t think it was my prerogative to tell neither the breeder nor the purchaser of my opinion. The horse is racing in Hong Kong and last week I looked for the performance of the now 6 years old.. But I was wrong because he has won two minor races bit it took 38 starts. PRI analysis might have avoided the expenditure for such a limited return.