the answer is 24 to the best of my understanding. in a 2003 posting this article indicates 24 horses. there were 23 because a horse got a fever. I don't know if there has been a difference in competitors from 2003 to 2006. reference ===>> http://horseracing dot about dot com/od/melbournecup/l/aa110303a.htm
In the United States, on the first Saturday in May when they run the Kentucky Derby, 20 horses, the largest field allowed, will try to win the Run for the Roses. Today, because horse racing is short on horses, most horse race fields are between 7 and 12 horses. There's a great article on this whole subject at a very good horse racing forum - horseracegame.com/community. Some pretty good comments and feedback on the subject.
24 horses ran in the 2010 Melbourne Cup.
24 horses ran in the 2008 Melbourne Cup.
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A limit of 24 horses can now run in the Melbourne Cup for safety reasons, though more than that have run in it in the past.
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You can watch the horses run at Flemington.
3
shocking
Thoroughbred horses.
Normally about 24!!
Shocking.