After 20 days of NBA basketball, the New Orleans Pelicans are the worst defensive team in the league, allowing 109.9 points allowed per 100 possession. That's bad. Like legitimately bad. Consider that the worst defenses of the past two seasons clocked in a number close to that (the worst defenses in 2013-14 & 2014-15 clocked in at 109.1 & 109.6 points allowed per 100 possession).
Don't panic yet though. A lot of that is small sample size (9 games) and playing the only 60-win teams from last season (and 2nd and 6th best offenses in 2014-15) four times in the span of 9 games (not to mention the Dallas Mavericks twice and the Toronto Raptors).