A big reason for the sudden turnaround is scheduling:
Date Opponent SRS Result
1/6/2012 Indiana Pacers 16th L , 74-87
1/11/2012 Dallas Mavericks 8th L , 85-90
1/13/2012 Chicago Bulls 4th L , 79-88
1/14/2012 @ Indiana Pacers 16th L , 83-97
1/16/2012 Okla. City Thunder 6th L , 88-97
1/18/2012 Toronto Raptors 26th W , 96-73
1/20/2012 Phoenix Suns 21st L , 71-79
1/22/2012 @ Washington Wizards 28th W , 100-94
1/23/2012 Orlando Magic 19th W , 87-56
1/26/2012 @ Orlando Magic 19th W , 91-83
1/27/2012 Indiana Pacers 16th W , 94-87
1/29/2012 Cleveland Cavs 24th L , 87-88
1/31/2012 @ Cleveland Cavs 24th W , 93-90
2/1/2012 Toronto Raptors 26th W , 100-64
However, I find their play in Rondo’s absence to be interesting. During the losing skid, Rondo was their best player, possibly the lone player on the team playing at an acceptable level. Garnett & Pierce struggled to make shots; Allen couldn’t even get shots. When Rondo went down, Avery Bradley took over at PG and has been terrible, giving the team practically none of Rondo’s production… But Garnett, Allen, and (especially) Pierce are suddenly playing extremely well. This is not the “Ewing Theory” in action, of course; it’s more a reminder that seasons are filled with strange streaks. Most of them get smoothed out in the long run, but they sure can be mystifying in the moment.