Because
The Derby
has always been viewed as the supreme test for three year olds with a view to establishing their credentials for stallion careers.
The British Pattern is based around the good of the Breed, which is why geldings are not allowed in any of the Classics.
It has never seemed logical to bar geldings from big races.
How does having geldings in the race stop it being the supreme test of stallion prospects? It can hardly be a supreme test if certain horses are not allowed to run. A gelding might finish eighth, fifth, third or even first, but the “best” stallion prospect will beat all the other stallion prospects. Is it just because the geldings do not have to carry a couple of small extra weights? Why is it not “good for the breed” for stallion prospect to be tested against geldings as well as entire horses?
.
Because geldings would enjoy a possible adavantage in the Derby. The Epsom classic looks to test speed, stamina and temperament.
The natural state for a 3yo colt is to be interested in fillies and mares and must overcome these and other distractions to win the race.
Gelding a horse is often done to pacify and control temperament therefore a gelded 3yo in the Derby has less to overcome…therefore there
may
be a potential advantage.