Is Best to the Best the Best way to find or breed the Best Racehorse?

Calogues are now out

There has been some recent discussion about the wisdom of old adage “Breed best to the best and hope for the best. “ The apparent failure of the outcome of breeding from quality mares that have failed to pass on their racing talents to their offspring has fueled this discussion. I thought it may be helpful to comment on these matters now Catalogues are available. The information may be of assistance to those wading through the catalogues. Remember the catalogues are primarily selling documents. They certainly give you information about the stallion and the dam but these are racing facts crossed with racing facts. What is needed is information on breeding facts crossed with breeding facts.The horse’s potential racing ability can be established by a more detailed examination of the pedigree at the top of the page. PRI analysis is one way of doing this.

Importance of Genetics

Racehorses are complex individuals whose success at the end of the day can depend on millimetres and there are many factors governing success or failure. Training, health, nutrition, attitude, are all important factors. Luck is the most uncontrollable element of all (wet tracks, barriers, interference in running, jockey competence etc.).  All important but not considered here. However, unless the horse has the genetic ability to perform these factors become inconsequential.

The pedigree of a horse is said to govern only 30% of its ability. If this is true then it is the critical 30%. A good human analogy is the  athlete. Consider a young person of great athletic ability who trains hard, has a great competitive attitude and is willing and looks forward to making the necessary sacrifices in lifestyle each athlete has to make if they wish to reach the top. This person wants to play basketball at the NBL level but this athlete is only 5ft tall. What are the chances of them making the grade? Very little.The task is beyond their genetic capability. So it is with horses.

An Example of Breeding Quality Mares  to the Best that worked

Firstly let’s look at the big picture of crossing the Best with the Best. The English Oaks commenced in 1779 one year earlier than the English Derby. In the last almost 250 years how many Derby winners have sired a Derby winner from an Oaks winner? None, until 2014 when the paradoxically named Australia (Galileo-Ouija Board) saluted. There is some controversy that this was the first example because in 1995 Lammtarra (Nijinsky-Snow Bride) won the Derby but Snow Bride had become an Oaks winner after Aliysa, who was first past the post, was disqualified. Only five other Derby winners have been out of Oaks winners

Australia (Galileo-Ouija Board) winner English and Irish Derbies 2014

The fact that the mare and stallion may not be genetically compatable and able to produce a high quality horse is not usually mentioned in the discussion on the poor breeding performance of successful race mares.   Tthe breeding career of Coco Cobanna shows this. Coco Cobanna was a high quality race mare. In 2000 she was winner of the G1 AJC Oaks, 3rd in G1 SA Oaks, and winner of the G1 Metropolitan Handicap and the G3 Colin Stephens. The Table:below sets out her breeding career

What is a PRI?

The factor PRI (Pedigree Racing Index) in the above Table is a way I calculate a theoretical racing performance from looking at various stallion crosses. In data base I have constructed the PRI values range from 100 to 43.3; only two horses have reached the perfect 100 and they won almost $6m in stake money.  The PRI values calculated for each of Coco Cobanna’s foals pretty well parallel their racing performance. All the major sire lines available in Australia at the time, Danehill, Storm Cat, Mr Prospector were tried using high quality sires (the Best); the only sire line missing is perhaps Sir Tristram. 

A breeding strategy of Best to the Best cannot be dismissed on the basis of one result. Coco Cobanna is a good example of breeding quality mares to the best bloodlines around and was definitely a sound plan. But it failed to deliver its objective. To be statistically significant this result will probably require looking at least 20% of the horses in the thoroughbred data base which now probably exceeds 2.5m. Even with modern computers a Herculean task. However, it does show that calculation of an index like PRI will give guidance to the probable racing performance of any horse. In retrospect, armed with the knowledge above Coco Cobanna would have been better served by a Danehill son (2002 was the last year Danehill himself stood).

So my advice to  people who look at catalogues is to do more homework around the mare and its relations. Look at the broodmare sire carefully. Does it have SW from the stallion whose progeny you are looking at. If not, what about other stallions in the sire line?

Good luck, we all need plenty of that.