Does the ability of the Dam correlate with the ability of her offspring?
An aspect that sparked my interest when researching the blog on Sire Uplifts on Mare Quality was whether the quality of the mare indeed had a significant influence on the ability offspring showed on the track. A passing look gave me the indication that Mare Quality, judged by Highest Official Rating (OR) achieved on the track, was not a good indicator of the likely ability of offspring.
That’s pretty shocking when you look at the values thrown around at the Bloodstock markets when Blacktype Fillies are involved…
Across my database I was able to match the ORs achieved by females on the track with around 17,100 offspring since 2008. We will use that as our analysis dataset.
Casting our eye over the highest rated horses in the UK and Ireland since 2008, already interesting is the Official Ratings achieved by the Dams of our top two rated horses in the dataset; Cracksman (Rhadegunda — 84) and Battaash (Anna Law — 45). Though we do see a smattering of 100+ rated mares giving birth to the higher quality offspring.
I then decided to flip down to the bottom part of the dataset and horses rated below 50. At the 49 Dam Official Rating mark I was intrigued to find some famous names and proper 100+ horses in the form of George Bowen, Baron Bolt and Ventura Tormenta.
We then took the entire dataset of 17,100 horses and ran a Pearson Correlation between the Dams’ Highest Achieved Official Rating and that achieved by offspring on Track. There was a low correlation between the two of 0.145.
So, a small correlation but nothing strong or statistically significant.
To display this on an individual stallion level, let’s take a look at a couple of sires as illustrative examples.
We took Dubawi’s progeny as the first example, with 1470 horses in my dataset where I was able to match the offspring with a Dam that raced in the UK and Ireland after 2008.
With Dubawi there is little correlation between the Dam Quality that has been sent to him for breeding and the quality of progeny on the track.
Now let’s take a look at how Frankel is tracking so far…
Again, remarkably consistent results when compared with Dubawi progeny. Little or no correlation between the on-track ability of progeny and that of the Mare.
What then, of the top horses racing in our jurisdiction?
To further breakdown we then went further into the Offspring that have achieved an Official Rating of 100+ on the track, and captured the Highest Achieved Official Ratings of the Dams into ranges. There were 1086 horses in my dataset that had achieved an Official Rating in the UK & Ireland above 100. This analysis does display a marked preference towards 70+ rated mares, although the 108/1086 horses that came out of unrated or <40 rated mares could present breeders with a value opportunity.
From that initial bit of exploratory research I would posit the hypothesis that the quality of the mare is not a deciding factor in the ability of the offspring. Breeders could be spending lots of money on Blacktype fillies are recouping little return on investment. That said, breeding with a mare who achieved >70 in terms of Official Rating on the track, does appear to be the best formula to deliver horses rated 100+ in the UK & Ireland.
For further analysis and data requests you can find me on Twitter @TomWilsonHorses or email me directly tomwilson1986@btinternet.com.
