When Secretariat’s necropsy in 1989 revealed a heart estimated at 22 pounds, a racing metaphor became biological fact. This episode traces how a coin toss with the Phipps family gave Penny Chenery the foal that combined Bold Ruler’s speed with Something Royal’s stamina, and how blinkers, groom Eddie Sweat and jockey Ron Turcotte shaped a champion.

We break down his 1973 Triple Crown, including a Kentucky Derby run with each quarter faster than the last, a bold Preakness move and a 31-length Belmont win in 2:24 that still stands as a dirt record. We also explain his record syndication, the hidden abscess behind his Wood Memorial loss, and the X-factor theory of his legacy.

• The biomechanics of his sloped croup and nearly 25-foot stride
• Why a $6.08 million syndication put enormous pressure on his three-year-old season
• How Secretariat captivated a nation weary of Watergate and the Vietnam War
• Why fans refused to cash their winning Belmont tickets
• How the X-factor theory explains his success as a broodmare sire