Sorry, Khalil Mack ... the Chicago Bears do NOT have the best defense in the NFL -- so says Patriots DB JC Jackson, who tells TMZ Sports that honor belongs to New England!
"I feel like we've got the best defense so far," Jackson says ... "I feel like we've got the best defense in the league."
The Pats have steamrolled to a 4-0 start ... and a big reason for that is the 11 dudes NOT on Tom Brady's side of the ball.
Through the first quarter of the season, the Pats are allowing a league-best 243 yards per game ... and have TEN interceptions -- at least 5 more than every other squad in the NFL.
For those reasons, JC -- who had two picks against the Bills on Sunday -- says the Pats deserve the NFL's top D title ... telling us, "Right now, we the best defense in the league."
By the way, JC was praised by Brady after his huge game in Buffalo over the weekend ... and when we asked what it's like getting compliments from the G.O.A.T. -- JC says it's flat-out awesome!!