# of Starts of Previous Triple Crown winners

[Linny]

Hard to compare the pre-Secretariat TC winners to those of the "modern" era. Remember, the phrase was only coined in the late 1930's during War Admiral's era. The 3 prior winners were effectively retroactive. While winning those three races was a big deal because they were important races, I'm not sure that at the time there was such a grail-like status attached to the feat. When it wasn't won for 25 years, appears to be when it attained that status. The more recent 37 year drought elevated it even more.
Also, the colts that won before Secretariat did so in the pre-syndication/stud deal era when it was assumed that the colt would retire to stud at the farm of the owner or the farm where the owner's mares resided like Belair/Claiborne etc. There was no big cash out coming from retirement and insurance companies weren't forcing retirement via insane premiums.
Many of the old style owners who were going to stand their colts recognized that testing their TC winners repeatedly against older runners was the best way to determine their viability as a stud prospect. In an era when horses run 10-15 times, every loss matters. Obviously, no one wants to send a horse over and lose, but in an era when horses raced into shape and raced often, losses didn't have so great an impact.
Today there is far more emphasis on protecting the value and making a deal while the value is at its peak. The numbers involved are so big that I don't blame anyone, but the sporting model has given way to the business model and I don't see it changing.