Despite the Indiana Pacers’ utterly delightful alternate unis commemorating one of the greatest basketball movies of all time, the Boston Celtics are the real Hoosiers of the NBA. Hell, they’re arguably more Hoosiers than the actual Hoosiers being that there’s no Jimmy Chitwood equivalent among their ranks. First-time All-Star Isaiah Thomas is as close as it gets.

With these Celtics, it’s all about strength in numbers and an airtight bond that makes them one of the toughest outs in the league. Just ask the Clippers, Cavs, Thunder, or Bulls (or Warriors, who they took to double overtime in December).

Funny thing is, they were never supposed to be this good, this fast. Before acquiring Isaiah Thomas at the trade deadline last season, Danny Ainge had written off 2014-15 as a rebuilding year. They jettisoned Rondo and handed the reigns to rookie point guard Marcus Smart and took a flyer on Evan Turner, whose value at that point was just about as low as it gets. Even with Thomas in tow, everyone assumed they’d land back in the lottery last summer. That is until the Celtics won 22 out of their final 34 games of the season to secure the seventh seed in the Eastern Conference playoff race.

Ainge mostly has Brad Stevens to thank for that. The third-year coach has coaxed the type of effort and production out of this rag-tag group that you only dream about. After all, that’s exactly what made him so coveted during his time with Butler, where he led similar underdog teams to back-to-back National Championship games.

One of the main things that makes Boston so tough is their stifling defense, which ranks fifth in the league as they give up a stingy 100.1 points per 100 possessions. That’s even more remarkable when you consider they’re the third fastest team in the NBA, behind just the Sacramento Kings and Golden State Warriors in pace.

Their perimeter defense is where it all starts. They hold opponents to just 32.9 percent shooting from three-point land, which places them in the top five of that category along with the Bulls, Pacers, Warriors, and Spurs. It shouldn’t come as a surprise considering their personnel. Marcus Smart, Avery Bradley, and Jae Crowder are all lock-down defenders. Smart and Crowder both rank in the top ten at their respective positions in defensive real plus-minus, and though Bradley’s real plus-minus numbers don’t adequately reflect his value, he’s still one of the best on-ball defenders in the game and boasts a net rating of +5.1.