Rasmussen Factor (another
The following study is based on an evaluation of all horses sold at public auction in North America in 1999. 14,000+ weanlings, yearlings, or 2-year-olds were sold at public auction in North America in 1999. Of these 8,309 sold for $10,000 or more. This is the population used in this study undertaken by David Dink and I have permission to use the data for this case study.
RF qualifiers are defined to be inbred through both sire and dam to a “superior” female within five generations). The definition of “superior” used by Mr Dink is a mare who was a stakes winner herself or who produced one ore more stakes winners. Only 3 mares being inbred to did not qualify using the above definition of "superior" and these are Mixed Marriage (reine de course) , Bebop II (stakes placed and producer of a number of stakes placed horses) and Princesse Commene (half sister to a number of stakes winners and producer of a stakes placed foal). To simplify matters I have included these 3 mares into my definition of superior.
Table 1 : this table shows the 29 stakes winners who are RF qualifiers as set out above.
Of the 8,309 horses sold 508 went on to be stakes winners (by SITA, black-type rules).
29 in Table1 above and the remainder in Table 6.
The following table shows a breakdown of how the the sold horses have faired.
Those bred without have outperformed (in percentage terms) those with the Rasmussen factor.
The table above does not take into account the number of races won and it is conceivable that the 29 qualifiers won better races and more often than the non qualifiers.
To try and quantify how good the races won were and how often they were won a 4-3-2-1 rule has been deployed. i.e. 4 points awarded for each Gr1 win, 3 points for each Gr2, 2 points for a Gr3 and 1 point for a non group/graded stakes race. The 29 RF stakes winners accumulated 59 points (see Pts column in table 1 above). For example Minardi has 8 points because he won 2 Gr1 races.
So those stakes 508 winners gathered 1,615 points in total at an average of 3.18 per horse. The RF qualifiers did significantly worse than average with just 2.03 points per horse.
Another aspect that needs to be looked at is the price of the foals.
The sales price of RF qualifiers is slightly more than the non-qualifiers.
So what about the sales price of those that went on to be stakes winners?
My conclusion would be that this study demonstrates that, in this particular instance, you would have to pay more to buy a horse inbred to a superior mare and win less!
Using different approaches I have done studies that suggest that deploying RF in a mating is likely to be more successful than not doing so. Even so, I have concluded that I am not sure that it is the process of inbreeding to a superior mare that is working because more often than not I find the mares back in the 4th generation are often behind top class stallions like Northern Dancer, Mr Prospector, Halo etc etc.
As well as the data above mention was made of different studies undertaken and this made me think about the percentage of foals inbred using RF. A figure of 4% is often quoted has being the the percentage of breedings made that incorporate a RF inbreeding. This percentage, whilst maybe correct at one point in time, cannot be used in a static sense and I think it probable that it should be treated as perhaps the lowest percentage of these breedings found. The last sample I did was with foals 40000+ foals born 1998 through 2001 and I concluded that nearly 9.4% of foals were inbred using a RF with just 5 mares accounting for 60% all all such inbreedings and two, Natalma and Almahmoud, accounting for 30% on their own. Mr Dink's data above has those inbred using RF at 559 / 8309 = 6.73%.
This percentage of animals inbred using RF I think is very important. As well as this study Mr Dink also related that in 1995-97 study the % inbred was 5.81%. Even more importantly, albeit using a small sample, in a 1970-1974 sample the % was found to be a staggering 15.33%. In 1980-84 using another small sample this has decreased to 9.15%. So not exactly a static 4% of inbreedings are RF one's.
Mr Dink remarked that although the 1970-74 sample result seemed very high one has to understand the chronology of pedigrees in that most of those duplications involved Plucky Liege (Sir Gallahad III, Bull Dog, et al.), Selene (Hyperion, Pharamond, Sickle, et al.), or to a lesser extent some combination of Nasrullah, Royal Charger, and/or Mahmoud.
Is the RF % rising again? I have no doubt it is and again through very few sources. Understand how we find instances of mares like Natalma, Almahmoud, Somethingroyal, Lalun etc and the reason why the % is rising should be pretty obvious.
This rise and fall is worth considering. In a couple of generations do we see another fall and then another rise as inbreedings to the likes of Razyana (dam of Danehill) or similiar become almost unavoidable.
The 29 RF qualifiers who won stakes races were produced in table 1 above. Other tables available are:
Table 6 which is a list of all 479 non-RF qualifiers who won stakes races can be found here.
Table 7 is a list of the RF qualifiers that did not win a black type race and can be found here.