In calendar year 2021, the Boston Celtics were at a crossroads.
They had a 17-19 record and were severely underachieving. Their defense was good enough to stay within the top 10 (107.5 DRTG, 9th over that period). But their offense struggled mightily (108.3 ORTG, 20th over that period). A sturdy defense was canceled out by an inept offense, resulting in them being a net neutral as a team.
Being a net neutral with a superstar such as Jayson Tatum, a two-way stalwart in Jaylen Brown, and a defensive hound such as Marcus Smart was arguably the highest degree of underachieving seen in recent years.