Although Bolt ran a 19.93 when he was 17 in 1984, it happened in the year in which he turned 18. To be eligible for a U18 best, World Athletics requires that an athlete not turn 18 during the calendar year, according to a U.S. Track and Field official. The same applies to U20 records. Bolt turned 18 later in the year in which he ran the 19.93. Knighton turned 17 in January and thus cannot turn 18 this year.

“Statisticians also keep unofficial lists of bests by someone in each age group. This is based solely on the age of the athlete on the date the performance happened. An athlete could set an ‘age-17 best’ on a Monday and then turn 18 the next day. These are not officially recognized by World Athletics,” Susan Hazzard explained in an email to The Post.

Knighton has qualified for the upcoming Olympic Trials and would be younger than any U.S. Olympic male track and field athlete since Jim Ryun in 1964, according to Olympedia.org. However, Noah Lyles, Kenny Bednarek and Terrance Laird have each run 19.81 or better, making Knighton a long shot.

A 6-foot-3 wide receiver for his high school football team, Knighton came to sprinting as a high school freshman when his football coach recruited him for track. Although he said he has been recruited by Division I football teams, choosing to go pro in track was “a no-brainer.”

“In track, the success of my career is fully in my hands,” he told Track and Field News in February, “and I know that I can do it.”