Back in mid-December, we posted an article comparing the rookie seasons of Malcolm Butler and J.C. Jackson — two cornerbacks who joined the New England Patriots as undrafted free agents but went on to play considerable roles on the 2014 and 2018 squads, respectively. Back then, the comparison favored Jackson: he played more snaps, allowed a lower completion percentage in coverage, and did not give up a single touchdown.
All in all, Jackson was off to a quicker start into his first NFL season than Butler. The now-Tennessee Titans defensive back, of course, became the benchmark for undrafted rookie play in New England when he made one of the biggest plays in NFL history.