Overview
Five teams went into week four of the NFL season with a 100% record, but only three teams remain unbeaten after Sunday's action.
Source
Originally published at www.bbc.co.uk.
Politics
Chiefs and 49ers remain unbeaten - five things from NFL week four
Key Takeaway
Five teams went into week four of the NFL season with a 100% record, but only three teams remain unbeaten after Sunday's action.
Frequently Asked Questions
What is "Chiefs and 49ers remain unbeaten - five things from NFL week four" about?+
Five teams went into week four of the NFL season with a 100% record, but only three teams remain unbeaten after Sunday's action.
Who reported this story?+
This story was reported by BBC News.