Racehorse Soundness and Durability Statistics

The Grayson-Jockey Club Research Foundation released a report on the average number of progeny lifetime starts and percentage of foals that started in at least one race for a select group of Thoroughbred stallions standing in the United States. Stallions included in the listing had to have ranked in the top 200 by progeny earnings for the 2010 calendar year. The criteria were chosen so as to include stallions that produced offspring with above-average performance. The figures might indicate which sires have better records of continued soundness and durability in their offspring.

For Thoroughbreds, the average number of lifetime starts is 18 for horses that make at least one race start. Horses that never started a race are not included in this figure. Only 32 of the top 200 stallions (16%) had progeny that started as many as 18 times.

Among all Thoroughbred foals, only about 70% ever start in a race, and stallions in this report were well above this average, with the top 100 stallions (50%) on this list having had at least 70% of their progeny reach the starting gate.

As to yearly (not lifetime) starts, the average for all Thoroughbreds has dropped from around 11 per year in 1960 to just over 6 in 2010. Many factors have influenced this decline. One of the most important is the trend toward retiring successful young horses to stud after fairly brief racing careers.

Just under one-third of stallions on the list sired stakes-winning horses that raced after their three-year-old year. This number could indicate that a relatively small percentage of horses are durable enough to continue racing year after year, or it could be another reflection of the retirement of successful horses after only a few years at the track.