The lack of a jump shot for Rajon Rondo has been well documented since the inception of the New Big Three Era. In fact, it's been over-documented and a bit overrated. Of more importance is his abysmal free throw shooting and rapidly declining rate of even getting to the free throw line. Kobe Bryant and the LA Lakers were amongst the first to deploy the "sagging off" tactics when defending Rondo.
The main concept behind this defensive strategy was to give Rondo a ton of space to shoot the ball, thus limiting one of his greatest strengths: driving, penetrating the defense and creating numerous opportunities for his teammates to score in a variety of ways. Recently however, Rondo has been knocking down that mid-range jumper slightly more. But one new wrinkle that Doc Rivers has implemented into the offense is having Rondo initiate a set from the high post. Take a look at a handful of samples with the video below:
Rondo High Post 1: In this first set, Ray Allen brings up the ball and makes the entry pass to Rondo who is posting up Orlando's Jameer Nelson. As Ray cuts to Rondo's right, he sets a baseline screen for Paul Pierce. Orlando, especially Brandon Bass, assumes the play is designed to get Pierce a jumper on the left wing. But watch from the beginning as Ray cuts down to set a screen for Pierce, Shaquille O'Neal is also setting a screen for Kevin Garnett to pop-out. This is most likely the second option off this set as Rondo does a great job of recognizing that Bass bites on the initial option, thus freeing up KG for his trademark jumper.
Rondo High Post 2: In this example, Pierce hands the ball off to Rondo who is now set up in the high post on the right side of the court, again being defended by Nelson. This time however, it appears as if Ray is going to run the baseline in a version of the "Floppy" play, but it's actually designed to isolate Shaq on the low post against Dwight Howard. By having Rondo set up with his back to the basket here, it forces Nelson to defend him more closer, thus eventually creating the necessary angle for a better post-entry pass to Shaq.
Rondo High Post 3: Using another version, Rondo brings the ball up himself, then backs Nelson down into the high post. Initially, Ray is trying to screen Turkoglu to free up a cutting Pierce (to set up down low) but Turkoglu does a good job of fighting over the screen. Rondo then is alert enough again to recognize Bass' mis-read on the play and tosses it to KG who is wide open again for the jumper.
Rondo High Post 4: In this example, the Detroit Pistons use the bigger Tayshaun Prince on Rondo. Pierce brings the ball up and gives it to Rondo in the high post on the left side. In what looks like another option off of the "Floppy" set, Ray Allen is cutting on the baseline presumably to catch-and-shoot a Rondo pass from the high post (they have run this as well). Instead, Rondo quickly hands it off to a cutting Pierce who drives to the hoop and draws the foul. In the first example, Rondo could have done the same thing when Ray was the passer/cutter but that was a different option.
Rondo Low Post: Every once in a while, the Celtics will mix in Rondo working from the low post as well. In this example, KG hands off to Ray who starts in the high post. He then dumps it in to Rondo who notices Paul Millsap hedging over to double-team him. At the moment he hedges, Rondo sniffs it out and tosses a pass to KG who is open and knocks down the jumper.
Basically, Doc and the coaching staff (and likely Rondo as well) are being creative in attempting to beat the "sagging" defense. What it does is creates the necessary space and angles for Rondo to run the normal plays without waiting until the shot clock is under 10 seconds. It also confuses the defense a bit with the several screens trying to free up at least one option. They don't run it often but it's just another wrinkle of their offense that they can go to while Rondo continues to improve his jumper. The free throws on the other hand are a whole other issue.