Secretariat Won the Belmont by 31 Lengths and Still Holds All Three Triple Crown Records

Secretariat swept the 1973 Triple Crown and set a track record in each of the three races. All three still stand more than fifty years later. He won the Belmont Stakes by 31 lengths, the largest winning margin in the history of American classic racing.

His Belmont time of 2:24 for a mile and a half has never been seriously approached, by any horse, on any dirt track. The Kentucky Derby record of 1:59.40 also still stands, and so does the Preakness mark. Setting a track record in one leg of the Triple Crown is a career achievement. Setting one in all three, in the same five weeks, has happened once.

The Derby is the run that professionals point to. He covered each successive quarter mile faster than the one before it: 25.2, 24.0, 23.8, 23.4 and 23.0 seconds. Horses do not do that. A thoroughbred at racing speed decelerates through the final furlongs, and the winner is normally whichever animal slows down least. Secretariat was still accelerating at the end of a mile and a quarter.

The Belmont margin is what makes him famous, and the manner of it is stranger than the number. He and Sham went out at a suicidal pace for a mile and a half race, a tactic that should have destroyed both. Sham collapsed and finished last. Secretariat kept going and drew away alone down the stretch while the commentator gave up on describing the field.

A necropsy after his death found a heart weighing around 22 pounds, against a normal thoroughbred heart of eight or nine, so close to three times the usual size. The counterarguments are real: Man o' War lost once in twenty-one starts while carrying weights that would be considered abusive now, and won by margins nearly as absurd. Frankel retired unbeaten in fourteen races on turf and was never once seriously tested. Citation and Kelso have stronger overall race records than Secretariat's 16 wins from 21 starts.

On career consistency, Man o' War and Frankel have the better claims, and Secretariat did lose five times. But no horse has produced a single afternoon like that Belmont, and the clock has agreed for half a century.

The verdict: Secretariat. The 1973 Belmont is the most dominant performance in any sport. Frankel for the unbeaten record.