Are 3-year olds the best?

Question
Hi--

The most-reknowned American horse races are the triple-crown races for three-year olds.

Is the age of three the prime for a race horse? Put another way: are most track and world records held by three-year-olds.

Many thanks,

Steve
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Answer
Hi Steve,
        What a good question. Normally I would have an answer for you but on this occassion, I think I might do a bit more research before answering.
In most well developed racing countries, 3yr olds are a glamour group but I think it is unlikely that they hold more world records than any other age group aside from age group races. I suspect their record beyond 2000m would not be as good as older horses however I will find out and reply to your email address.
Regards,
Don Boddie
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