What is the fastest recorded 40 yard dash in the NFL?

Answer:

Rondel Melendez (in 1999) and Chris Johnson (in 2008) both share first place at 4.24 in the list of top official 40 yard dash results recorded at the NFL Scouting combine since 1999, the first year electronic timing was implemented at the NFL Scouting Combine. Prior to 1999 40 yard dash times were somewhat unreliable and often prone to exaggeration. However, in 1986, Auburn's Bo Jackson is said to have run the fastest 40 yard dash at an NFL combine, with a reported time of 4.12. This time was obviously scrutinized, but a time of 4.18 run by Jackson within the same week certainly added some support to the legitimacy of the times.
However, other claims are that:

• Michael Johnson (3.98)
• Chris Johnson (4.03)
• Ted Ginn Jr. (4.06)
• Dieon Sanders (4.19)
• NFL DeAngelo Hall (4.21)
• Michael Vick (4.22)

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