According to figures released Tuesday by Equibase, through the first three-quarters of 2021 wagering on U.S. horse racing is up 13.8% over 2020 totals. At the end of September, $9,498,141,414 had been wagered on the sport, a sizeable increase over the comparable figure of 2020 when $8,346,543,422 had been bet. With a strong final quarter, the amount bet on U.S. racing for the year could top $12 billion. That would be the most bet during a year since $11.4 billion was wagered in 2010. The record for most wagered in...