In today's NBA, it is difficult to surprise defenses with tricky offensive play-calling. Advance scouts relay play calls to a team's video staff; every game of the NBA season is logged by play call, play type and a number of other factors. Two weeks into the season, each NBA team has already figured out opponents' terminology.
In the case of the Boston Celtics, new head coach Brad Stevens has a leg up on the competition. Coming from the college ranks, his terminology and style haven't been influenced by the pro game. He's come in with a whole new language and set of offensive principles, to which the rest of the league has had to adjust.
Still: It only takes a few more weeks for the rest of the league to get a handle on his offense—or so it should have. According to one NBA scout who spoke with Sports Illustrated's Ian Thomsen, Stevens' read-and-react offense has had defenses in a bit of flux:
The sets they run are more read-and-react type things than the normal execution of go from point A to B and then go on with this. He's got terminology of actions. But he's not going to play the two-man game or three-man game to see what the defense is going to give him. Instead he'll run an action and leave it to his players to read the defense.
That has made it difficult to get a handle on what he's doing, because he might get three different things on three possessions all on the same play call. What they ran the first time with that terminology isn't going to be the same thing they run the second time he makes that call.
It's not that offenses around the league don't possess wrinkles; most sets have options in some fashion. It's just that, in a typical NBA scheme, a play or set design is primarily looking for a particular pass or action.
If other options are available, players are encouraged to explore them. But if the play were to be run through in full, it would end the same way every time. In Stevens' offense, this is not the case. The same play can end any number of ways.
This is why the return of Rajon Rondo is so crucial to his scheme: With one of the highest basketball IQs in the league, Rondo can be relied on by Stevens to make the right decision.
In the days of Doc Rivers and the more experienced Celtics, specific play designs were executed with precision. The offense almost resembled that of a football team with Rondo at quarterback: Cycle through option No. 1, then 2, then 3 and so on.
With Stevens' Celtics, it's choose the best available.
Let's take a look at one particular Celtics play to see how Stevens allows his players to read and react.
On this play, both Boston bigs are stationed at the elbows, while the wings are spaced in the corner. Rondo dumps the ball into a big at the elbow and immediately cuts down the middle of the floor looking for the ball.
It's unlikely that he'll receive it, but sometimes a defender will turn his head and give up an easy bounce pass or lob. Rondo doesn't get the ball, so he immediately cuts strong side to set a flex screen for Jeff Green.
Green slices to the hoop, looking for the ball from Jared Sullinger. If he doesn't get it, he teams up with Brandon Bass on the weak side to set a double pin-down screen for Avery Bradley.
Bradley either curls or pops, reading the play as it develops.
On the strong side of the action, Rondo has a choice: Post up and back down his defender, lift up towards Sullinger for a dribble handoff or catch a pass from Sullinger in a compressed throw-and-chase—when a player follows his pass and sets an on-ball screen.
Here, he posts and gets the screen from Sullinger.
Ultimately the play fails because Sullinger can't quite get it to Rondo cleanly. But conceptually, Stevens' play design has no clear No. 1 option. It's up to Rondo to read the defense and react accordingly.
The next time down the floor, the Celtics run the same action.
You'll notice that while the play's fundamental concepts are the same, the execution is slightly different. This time Rondo hands the ball off to Green, who enters it to Sullinger. Bradley is now in the strong-side corner, and Green cuts outside of Sullinger before setting the flex screen.
He then lifts to the elbow for the dribble handoff, and the Celtics play out of it.
This can be particularly confusing for a defense if the play call is the same. Oftentimes, Boston's players will react based on certain reads, shifting gears into a slightly different play based on the initial action.
But mostly it comes back to Rondo.
By handing the ball off to Green, he removes himself from the main action. While this might not seem ideal, it's throwing new Sixers defenders into different roles on the same play. It's only a small wrinkle, but enough to generate a high-quality shot with the same action.
Here's another example—this time with a flare screen for Rondo. The initial setup is the same, except Rondo is now on the elbow.
Here he darts to the right wing off a flare screen from the opposite big, receiving the ball as Brandon Bass sets a back screen for Green.
This is where Stevens' offense once again becomes about reading the defense. Bass can either roll in for a side pick-and-roll or call for it in the post; it's up to Rondo to direct traffic here.
This time, Rondo dumps into the post, which is the correct decision. Bass has position on the block, and his defender is hardly putting up any resistance after getting slightly caught up in the back-screen action. Bass faces up and hits the short jumper.
A few moments later, the same play again.
This time Bass rolls in for the pick-and-roll with his defender, Lavoy Allen, expecting a post-up. When you watch the video of the play below, keep your eye on Allen.
Because he recognizes the action, he tries to anticipate by leaning his weight towards Bass before the catch—an attempt to shove him out of post position. Except Bass isn't posting up, and Allen is leaning too far forward since he's awaiting contact from Bass. This allows Rondo to easily slip around the pick, and Allen is completely out of position.
With Rondo in the lane and Bradley cutting backdoor, the Celtics grab an easy two points.
There's nothing particularly ingenious about Stevens' offense or the sets his Celtics are running. They've all been used in the NBA before, and teams know how to defend them. The problem presents itself when defenses can't jump into action because their recognition is late.
Stevens has adapted an offense that doesn't have a predetermined outcome. It is never stale because even his own players don't know what the specific result of the play will be.
The only requirement is to make the right decision. And with Rondo back at the helm, that will happen more often than not.