Here's the situation: 3rd quarter, Celtics down 3 and fighting like hell to get ahead of the Phoenix Suns. Phoenix has the ball out of bounds.
As the play starts, two players flare to either side of the court, clearing space underneath the hoop. Phoenix is trying to get a play to the basket… which you can tell as both of these players aren't making moves for the ball at all. They're getting out of the way. The video freezes as Steve Nash sets a pick on Kevin Garnett, who is guarding Amare Stoudemire.
The key to this play defensively is Rajon Rondo. As the pick is set, he's too far in the lane. There's no reason to be there. There's no one cutting in the lane for a pass… and if Nash gets a big lob pass at the top of the key to set the offense… so be it. On the first video freeze, Rondo should about a step to his left just to show Stoudemire that he doesn't have a clean path to the hoop. Rondo has both feet in the lane… when his right foot, at most, is all that should be in the painted area. Right now, Amare is turning the corner and seeing nothing but daylight instead of a white jersey in his way.
As the video progresses, you'll see that for some inexplicable reason, Rondo keeps on walking towards the top of the key. He's not playing any defense at all. He didn't do anything to help KG on the pick. He didn't show to slow do the guy coming off the screen. He certainly wasn't guarding Nash. I'm not sure what Rondo was doing. On the second freeze, you see Rondo and Garnett as the two players furthest away from the hoop.
So on a Suns out of bounds play under their own basket, you've got two Celtics completely out of the play: KG because of the screen… and Rondo because he was sleeping. If the ball didn't go to Stoudemire, it could have gone to Nash for a jumper.
I'll give honorable mention to Rasheed Wallace for sticking way too close to his man when, from that position, he could have stayed in the paint, still be 100% in the passing lane, and still have been in a position to bail out his boys by being in a better position to challenge the shot. But that's secondary.
The real culprit on this play was Rajon Rondo, who never played a split-second of defense on that play. It cost the Celtics 2 points in a tight game. It's a frustrating lapse that highlights what we've heard from C's management about him taking some plays off.