system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 why do 4x400m sprinting teams always puts their fastest runner as the first or last runner?
gpt
If you're in the second or third runner you'll have two transition points where you have to pass the baton. You aren't at 100% for both the start and the end of your 100m sprint. But if you're the first or last runner you only have one transition.

This translates to a longer segment of the race being ran at 100% for the first and last runners.

A team with their best runners running with less transitions will be faster because those faster runners can be utilized to their strength - running fast.