BOSTON If the Celtics continue to run through teams, many will point to Rajon Rondo's season-ending torn right ACL injury as the Celtics' turning point.
Truth be told, the C's began to get their act together well before their current four-game winning streak.
When the calendar flipped to 2013, it not only ushered in a new year, but around here it brought a new (but familiar) brand of Celtics basketball.
The C's went from being an across-the-board liability defensively, to one that could take the NBA champion Miami Heat to double overtime, win the game, and still keep them from scoring 100 points.
So while the Celtics offense has improved and they are getting much more production from their bench, it has been the collective efforts of the team defensively that has made them a much more competitive team in 2013.
"And it's not one thing; it's all the little things we thought we would do earlier in the year (defensively) that we're starting to do now," said C's coach Doc Rivers.
And the numbers make this emphatically clear.
This season, opponents are shooting 44.3 percent against the Celtics.
In the month of January, the C's limited teams to just 42.1 percent from the field, second only to Chicago in terms of field goal percentage defense in January.
And that stingy defense has also brought about a slight increase in turnovers. For the season, Boston ranks third in the league with 16 forced turnovers per game. In January, it went up to 16.3, which in that span ranks second only to the Denver Nuggets.
That number has been even better in Boston's two games this month, with the C's forcing opponents into 17.5 turnovers per game.
And more turnovers have led to an increase in points off those turnovers, which bodes well for a team playing a lot more "small ball" because of injuries.
"That's how we have to play now," C's guard Avery Bradley told CSNNE.com. "We have to make teams pay for turning the ball over. The best way to do that is score."
But with smaller lineups, the Celtics tend to play a more athletic bunch most nights which has helped cut down on the amount of dribble penetration that killed the C's earlier this year.
Dribble penetration often creates shot attempts inside the lane but not necessarily in the restricted paint area. Since January, those shots have been difficult to convert into points for most opponents.
Opponents shot just 33 percent in the non-restricted area against Boston in January, with only the Los Angeles Clippers and the Milwaukee Bucks doing a better job defensively in that category.
But there's a big difference. The Clippers have DeAndre Jordan and the Bucks have Larry Sanders, two of the NBA's better shot-blockers. Their presence on the court is a deterrent for many.
But the C's have been getting it done the old fashion way -- contesting shots.
And another favorite shot for teams is the corner three-pointer, in part because it's the shortest distance to the basket that can earn you three points.
Boston stepped its game up in defending that shot as well in January. Opponents nailed just 34.6 percent of their corner threes against Boston, which was the sixth-lowest mark in January.
The improved play defensively in 2013 is not that surprising to Rivers.
"Honestly, I thought we'd be able to pick this up earlier," he said. "When you make changes of nine players. It's just taken longer than I personally thought it should have."