What are “naps” in horse racing?

While racehorses nap (sleep) in their stalls, the term nap in horse racing refers to a public handicapper’s best bet of the day.

The abbreviation “nb” stands for next best and is often used to designate the handicapper or tipster’s second-best bet of the day.

Both terms are mainly used in the U.K. and Australia, as far as I can tell, and chances are you will never hear either term if you are a U.S. horseplayer.