What does “m/l” mean in horse racing?

“M/L” is a shorthand expression that is occasionally used to denote a horse’s morning line odds.

In parimutuel wagering, racetracks employ a linemaker, also known as an odds maker, who is responsible for setting the starting odds for each horse in each race. Those odds are known as the morning line in the U.S., though some European betting operations use the term “SP” – for starting price.

Once betting begins, horses’ odds change depending on the amount bet to win on each runner.

One thing to know about the morning line is that it is meant to predict how the bettors will wager on a race, not how the linemaker views each horse’s chances of winning. That can be an important distinction when a top barn whose runners always are fancied is entered in a race.