The 149th Kentucky Derby on Saturday marks 50 years since Secretariat's win

Eight of the 19-horse field this year are his great-great-great grandsons

Going further back, all but one of the runners has Secretariat in their pedigree 

Fifty years after Secretariat stunned the world at the Kentucky Derby on his way to a Triple Crown victory, the legendary racehorse's legacy continues through his progeny.

When the starting gates clang open on Saturday for the 149th Kentucky Derby at Churchill Downs, eight horses set to run in the 19-horse field will be great-great-great grandsons of Secretariat.

Among them is Forte, the early favorite at 3-1 odds, who won this year's Florida Derby with a thrilling late close down the stretch.