Does Birth Order Matter in the 2016 Kentucky Derby?

The 2016 Kentucky Derby favorite Nyquist is a firstborn foal. Birth order and the Kentucky Derby? Sounds like one of those fuzzy articles one would find in the Lifestyle section, right? Wrong.There’s actually merit to this.  Dr. E.J. Finocchio, an equine vet, undertook a study in 1995 about birth order and success of the racehorse. Dr. Finocchio studied 689 horses that won either a Triple Crown or Breeders’ Cup race, earned an Eclipse Award, or accumulated over $1 million dollars while racing. 

Those 689 foals were out of 680 dams. Dr. Finocchio discovered that a mare’s first five foals have a better probability of success. The percent of winners were: first foal (16.9%), second foal (21.5%), third foal (18.6%), fourth foal (15.3%), fifth foal (10.7%), sixth foal (8.1%), seventh foal (6.4%), tailing off to 1.5% for the 13th foal.

In addition, pedigree statisticians and theorists David Dink and Frank Mitchell undertook a study of their own, which was discussed in Mitchell’s classic book, “Racehorse Breeding Theories.” Dink and Mitchell ascertained that mares who were barren in a previous year produced offspring that were more successful on the racetrack than their siblings.

So what would account for these findings? In the majority of cases, mares are bred to a better class of stallions early in the mare’s breeding career in order to establish her worth as a broodmare. However, very good broodmares and blue hens continued producing high quality runners throughout their breeding span.

So, with that in mind, I reviewed the birth order of the last twenty-one years of Kentucky Derby winners and identified the following data: First foal/barren previous year: 50%, second foal: 20%, third and fourth foal 10% each, fifth foal 5%, sixth or greater 5%.

I also discovered a trend. In five straight years, from 2000 – 2004, the Kentucky Derby winners were second, third or fourth foals. In the preceding and succeeding years, the majority of the Derby winners were out of maiden or previously barren mares.

Over the last ten years, seven Kentucky Derby champs were either the first or second born. One was a third foal, and two were fourth foals.  However, the dams of the two foals who were the fourth-born were barren the previous year. Our Triple Crown hero  American Pharoah was a second foal and California Chrome was firstborn.  

Kentucky Derby Runners Up

What about the second and third place finishers in the Kentucky Derby?

Second place finishers birth order:

First foal or barren: 30%, Second foal: 15%, Third foal: 20%, Fourth – fifth foal: 0, Sixth or greater: 35%.

Third place finishers birth order:

First foal or barren: 40%, Second foal: 15%, Third - fourth foal 5% each, Fifth foal: 10%, Sixth or greater: 25%.

In nine of twenty Derbies (45%), two of the top three finishers were either out of maidens or previously barren mares.  

2016 Kentucky Derby Candidates

So, everyone wants to know what that means for the 2016 Kentucky Derby. Here’s the breakdown:

Louisiana Derby hero Gun Runner and Arkansas Derby third place finisher Whitmore are also first foals. Nyquist’s main rivals, Santa Anita Derby winner Exaggerator, Blue Grass Stakes champ Brody’s Cause and the previously undefeated Mohaymen are all third foals.

Tom’s Ready and Majesto’s dams either slipped or were barren the previous year.

Tampa Bay Derby winner Destin is a sixth foal and R. B. Lewis stakes conqueror Mor Spirit was seventh in line.  The only two winners of the Kentucky Derby in the last 20 years that were sixth in line or greater were Grindstone in 1996 and Charismatic in 1999, although Charismatic’s dam was barren the year before.

Just something else to consider as you weed your way through this year’s Kentucky Derby contenders.