Thirteen games ago, the Celtics looked lost. They had lost six out of its last seven games and were staring at a .500 record. They lacked identity and Brad Stevens was still tinkering with the starting lineup and the rotation. Over that stretch, they had been dismal on defense (with a 103.6 rating) and even worse on offense (100.3).

And then something clicked.

Even though they loss to a Knicks' team that played the second half without Carmelo Anthony, the Celtics mucked up the second half by going small with Jae Crowder at the 4 and Marcus Smart filling in on the wing. There was a sequence early in the third quarter when Smart fronted the 7'3 Kristap Porzingis and forced a quick shot that missed.

Frustrated, Porzingis fouled Smart on the rebound. Mismatches like that haven't been the norm for Boston's defense, but I think the mental approach that the Celtics have brought to every game since then is encapsulated in that play. Check out the GIF. The look on Marcus' face says it all: we're not intimidated and we're coming for you.

Since that game, the Celtics have turned their season around. They're 10-3 and while some of it can be attributed to their much improved offense (scoring +110 points in 9 out of their last 13 games), it's regaining their defensive identity that has really been the foundation for this run and hopefully long term, for the rebuild.

They've averaged a 99.3 defensive rating since January 13th (94.2 in their ten wins), but more importantly, their taking advantage and turning their defense into quick offense. Per NBA.com/stats, the Celtics are 2nd in the league in generating turnovers (17.5), 2nd in steals (10.2), 2nd in points off turnovers (20.3) and 2nd in the league in fast break points (19.5). Conversely, their transition defense has been very good. They're 3rd in the league at giving up points after turnovers (13.5) and 3rd in fast break points (10.6). If those differentials continue over the remaining 31 games, they could be hosting a playoff series in April.

How are they doing it? They're just so pesky and aggressive. Against Detroit on Wednesday, they had 8 steals and forced 16 turnovers. Here's one of them:

One of the Celtics' defensive philosophies is to keep the ball from penetrating the middle of the paint. That free throw line circle is precious real estate. Try to get in there and it turns into a wrestling pit where you have to grapple with the likes of Crowder and Smart. They ICE almost every pick with the guard forcing the ball handler to the sideline and the big keeping the action in front of him. That strategy effectively cuts the court in half and drives all the action to the corners. Stanley Johnson wasn't coming off a PnR, but if you're dribble the ball anywhere near the middle of the floor, you can expect someone to chip down and try and get a hand on the ball.

Here's Amir Johnson helping on a middle drive from Greg Monroe:

And here's Isaiah Thomas protecting the roll from Marcin Gortat and deflecting a John Wall pass with Johnson ready to rotate:

In their first meeting back in mid-December, the Celtics were without Marcus Smart and they only managed 9 fast break points and 11 points off turnovers against the Cavaliers. They'll have to double those numbers against the #1 team in the Eastern Conference. Unfortunately, since firing David Blatt and getting Kyrie Irving back, Cleveland has been much better with the ball; they're only averaging 10.9 turnovers in their last seven games and rank in the top-10 in opponents' fast break points and points off turnovers. Something's gotta give on Friday. The Celtics will have their hands full in Cleveland tonight, but as long as they're active hands, they should be fine.

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