Conversation so far:
who has the fastest 40 yard dash ever
John Ross broke the 40-yard dash combine record with 4.22 at NFL Scouting Combine.
Who before John Ross had the fastest 40 yard dash ever?
Chris Johnson registered a time of 4.24 seconds and broke the all-time mark set by Rondel Menendez, his record was later broken by John Ross.
How is the 40 yard dash timed?
Since 1999, the NFL has used partially electronic timing to determine 40-yard times at the combine.
Where is the 40 yard dash held?
The NFL Scouting Combine is a week-long showcase occurring every February at Lucas Oil Stadium in Indianapolis.

Question: The purpose of the test is?
Self-contained rewrite: What is the purpose of the 40 yard dash?