I interpret it to mean horses who raced between 1967 to 2017.
Secretariat would top my list. After him, the rest of my top 10 would be hard to choose and rank. Buckpasser, Dr. Fager and Damascus would have to be on it along with Affirmed, Seattle Slew and American Pharoah, The Bid, John Henry, and Sunday Silence or A. P. Indy. Tiznow and California Chrome would be on my list somewhere since I have to support our Cal breds.
But what about the fillies and mares? Lady's Secret will always have a special place in my heart. Then there's Rachel, Zenyatta, and so many others. Terlingua was not only a great race filly, but an extremely important broodmare.