The play was supposed to be for Paul Pierce. Celtics coach Doc Rivers likes to have the ball in Pierce’s hands in late-game situations because he feels Pierce is his best offensive player. Everyone knows this just like they know Pierce’s favorite move with the game on the line: the step-back elbow jumper.

The Knicks knew it Tuesday night with 19 seconds left on the clock in Game 2 and the Celtics down by a point and taking the ball out of bounds. This is Rivers’ time to shine and it’s also where his players have to be at their best.

“I’m hoping we never get in those moments, to be honest,” Rivers said the day after. “But I’ve been in the league long enough to know that as a player, in those moments, you better execute. You have to be on point.” 

The action began when Kevin Garnett set a downscreen for Pierce to receive the inbound pass from Rajon Rondo. Former Celtic Bill Walker fought through the screen and rode Pierce out past the 3-point line. That’s when the next option came into play.

Surveying the Knicks defense like a quarterback reading his progressions, Rondo decided to go with Plan B: Kevin Garnett in the post. “Rondo’s vision enhances everything,” Rivers said. “It’s no coincidence. Much of the stuff we run we try to use it with Rondo making the decision.”

Rondo doesn’t call many audibles, however. For one, he knows he’ll hear about it if the play gets broken. And two, the options are already in place. Within the set, Rondo is entrusted with making the right read.

“I don’t try to change things,” Rondo said. “All the plays and options we have our great. I don’t try to pre-determine where I’m going to throw the ball because I have three or four options. At the same time I have to go with my instincts.”

Once Rondo saw Pierce covered, he decided to go to Garnett, but before he could get him the ball he had to clear space. “The first thing he did was pump fake out, which was huge,” Rivers said. “Because then the guy guarding the ball has to shift that way.”

It was the tiniest of moves, just a look really, but it was enough to get Toney Douglas to flinch and that in turn helped open the passing lane. Rondo’s part in the play wasn’t done.

Rivers had put three other shooters on the floor in Pierce, Ray Allen and Delonte West and had them spaced behind the 3-point line. With Rondo the obvious choice to leave unattended off a double team, he cut to the basket daring the Knicks to leave him open from close range.

“The basket cut you’ve got to have because you got Paul, Ray, Kevin with the ball and Delonte, everybody’s behind the 3 [point line],” Rivers said. “They want to trap, well, they got to trap off somebody and they couldn’t.”

From there it was a one-on-one battle. Jared Jeffries expected Garnett to fake left and shoot the turnaround jumper off his opposite shoulder. Instead Garnett went into the paint and hit a contested hook shot over Jeffries’ outstretched arm. Jeffries had him played perfectly but Garnett used his height advantage to make a difficult shot.

Even thought the first option didn’t go as planned, so much had to go right for that play to be successful, from having the proper personnel on the floor to the correct read and ultimately the finish by Garnett. Putting your players in a position to succeed is what coaching at this level is all about and Rivers is acknowledged as one of the best in the business in these situations.

Sebastian Pruiti who breaks down plays for NBA Playbook — a must-read blog for NBA heads — named Rivers the winner of his inaugural “Clipboard Awards” contest. Pruiti chose the top three post-timeout plays each night and assigned points — three points for the best, two for the second and one for the third. (Here’s Pruiti’s breakdown of the two plays the Celtics used at the end of Game 1).

The Celtics offense, like most NBA offenses, relies more on sets and transition opportunities than specific plays during the course of the game. But when they are needed, that’s Rivers’ domain. 

“He does all the plays,” Rondo said. “We don’t have anything to do with it. We just execute them. Obviously we didn’t execute them well in the regular season. These last two games we’ve done a pretty good job of executing the plays, and obviously if you miss the shot you don’t look as good. But we made the shot.”

While Rivers likes to talk over plays with his assistants he is extremely hands-on to the point where his fingers often look bloody with the ink from the green sharpie pen he uses to diagram. He also likes to work them out in advance and typically ends practice with late-game situations. In one open practice earlier this season, Rivers set up a competition between the first and second team, that was basically make it-take it or as he yelled, “Get a stop, get a play.”

"In walkthrough, we go through end-of-game situations every day," Ray Allen said. "Some plays we use, some we don’t, but Doc likes to see the timing of it with the second team guarding us — seeing what’s open and what looks fluid. He’ll throw it in just to see it, just to feel it, and then at the end of the game, voila, you’re sitting there, and you’re running it."

The players are an ideal match for Rivers’ skills. He has great shooters in Pierce and Allen, a post presence in Garnett and a decision-maker he trusts in Rondo. “For me it’s just all about multiple options,” Rivers said. The fact that they are all veterans who have been with each other for four years doesn’t hurt either. Most of the time.

“That’s huge. The fact that you have veterans that trust each other, listen, that makes the whole thing,” Rivers said. “First of all they have IQs. When we get ourselves in trouble it’s because of their IQ. They’re so smart and then they see something else and they walk out on the floor and they’re telling one guy, ‘Hey, this is what we’re going to do.’ And then all hell’s going to break out and it’s something bad. That’s the danger with a veteran team. When they do it right and they read it, they’re pretty damn good.”

While Rondo isn’t the scoring threat, his role is extremely important as well. For the first years of his career he was often left on the bench in these late-game situations due to his shaky jumpshot and subpar free throw shooting. But Rivers trusts him to organize the sets and often uses him as the inbounder. “I’ve earned his trust I guess,” Rondo said in his familiar deadpan. Part of Rondo’s responsibility is also making sure everyone else knows where they’re supposed to be.

“There’s so much going on in the huddle, I even ask sometimes,” Rondo said. “Not in the fourth quarter. But during the game I’m thinking about getting Ray, Paul or Kevin a shot you may get a brain clog or something, like what did he just draw up? Guys do ask that. Everybody from KG to Ray to Paul, somebody has to know what’s going on.”

When it works, the Celtics execution at the end of the games is a work of art. When it doesn’t, it’s Jackson Pollack on a really bad day. For his part Rivers is deflective of the praise he’s received in these situations. “I’ve drawn up some [bad ones] too,” he said laughing.

Ultimately though, Rivers believes it comes down to trust and that’s a mutual relationship. “We all go with what we think we see and they trust it,” he said. “To me that’s the whole key.” That, and really good players in a well-designed set.