Algorithms are changing horse betting … and outraging gamblers

Wednesday, April 29, 2026 2:34 PM
Photo: By Grand Island Tour...8962496877/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=91341332
  • Dan Wolken, Yahoo! News

The sixth race at Del Mar on a random Saturday last July should not have been memorable in any way. Running for an $81,000 purse, a 4-year-old Thoroughbred named Nanci Griffith won the one-mile race and paid $14.80 to win on a $2 bet.

But for many of those who backed the winner, the payout was a massive disappointment. As the gate opened, the tote board showed Nanci Griffith’s odds at 18-1. When she crossed the wire, however, the odds had changed to 6-1, meaning those who held winning tickets collected less than half of what they might have expected at post time.