By Justin Barrasso His second time chasing a championship, the lightweight Brazilian knows well there’s marginal room for error in Saturday’s UFC Fight Night headliner. View the original article to see embedded media. Welcome to The Weekly Takedown, Sports Illustrated’s in-depth look at MMA. Every week, this column offers insight and information on the most noteworthy stories in the fight world. Rafael dos Anjos lost the lightweight championship in 2016. Half a decade later, he is taking steps to win the belt for a second time. Dos Anjos headlines this Saturday’s UFC on ESPNcard, meeting an in…