Why aren't the Kentucky Derby getting winners getting faster?

Longshot Giacomo won today in 2:02.75, which is about average for the era since 1950 in which Kentucky Derby winners haven't gotten any faster. He didn't come close to Secretariat's 1973 record of 1:59.4. Conditions were said to be close to ideal, so there's no excuse on that front.

As I graphed below, the winning times at the Derby have been stable since 1950. A reader writes:

The general consensus is that American horse breeding has been skewed by:

1. Drugs. Almost all American horses are on butazolidin and lasix. Illegal doping would obviously disguise underlying flaws in breeding even more than legal drugs. Doping not only skews underlying speed but disguises fragility.

2. Negative feedback loops. It does seem that horses are more fragile. This perception causes trainers to work horses less, leading to a sort of strange feedback loop, because the lack of strengthening opens up horses for injury. But trainers only get blamed for overwork, not under work. The end result is that it is not clear how durable a horse really is, making it harder to select for durability in a lineage or screen out fragility.

3. The Kentucky Derby itself. Since breeding in America is focused on the Kentucky Derby, Kentucky Derby winners as well as the type of horses that can get into the Kentucky Derby are over bred. Note that the type of horse that can get into the Derby does not necessarily correlate with overall genetic fitness, and a horse that wins the Kentucky Derby might not be the most genetically fit sire. For whatever reason there is generally a negative correlation between precociousness and stamina. I would argue that none of the horses in this year's Kentucky Derby have 1 1/4 pedigrees, let alone pedigrees to get 1 1/2 (most races in America are at shorter distances as well). Horses that have better stamina pedigrees are often not competitive early enough to get the graded stakes earnings to get into the derby. Kentucky Derby Winners get retired early (the money is in breeding, not racing), so genetics that might be evident from racing at later ages (even as an older 3 year old), such as fragility, or how much stamina the horse really has, are not discerned until after they have sired many offspring.

European racing does not allow even the legal drugs allowed here. There are important European races for four year olds, and many more races at longer distances. The fewer questions about the actual abilities of any given European sire increases the odds of breeding success, and therefore has resulted in superior genetic fitness of European horses, who are better than their American equivalents in average racing ability (on turf, of course) and durability.

My published articles are archived at iSteve.com -- Steve Sailer