Ray Allen calls it a language that only they can understand, they being Allen, Rajon Rondo, Kevin Garnett and Paul Pierce. It’s the language of their defense and through the first three games the Celtics may as well been speaking Swahili on the defensive end of the court. In different dialects.

Basketball may be the ultimate one-on-one sport but when you play like the Celtics play, or how we remember them playing anyway, it’s an expression of harmony as opposed to a solo performance. Attack, pressure, recover, help, help the helper. These are the words they use to describe their actions, but the communication runs much deeper to the point where even without the constant barking of Garnett it becomes an innate expression of movement.

“When I’m out there we’re more familiar with one another than having Sasha [Pavlovic] or Marquis [Daniels],” Pierce said. “Those guys not really playing with the starters as much as I have so there’s a little bit more defensive chemistry when I’m out there with those guys. We talk a little bit more. We know each other tendencies. I mean that’s what it is, truthfully. We’re more comfortable on both ends of the court.”

The Celtics were finally comfortable against the Pistons on Friday night in a 96-85 victory, their first game with Pierce in the lineup. It was a blowout that began to take shape in the third quarter when they opened up a 16-point lead in the first six minutes. They shot 71 percent and had 12 assists on 15 makes, all hallmarks of Celtics basketball, but it was the stops that led to the offense.

“That was the difference,” Doc Rivers said. “In the third quarter, we get mesmerized by offense, but in the third quarter it was the defense. We got multiple stops. It was the defense that we knew, that we’re comfortable with, and we hadn’t seen it yet this year.”

Asked why he hasn’t seen it yet this year, the coach was stumped for an answer.

“I don’t know,” he said. “I swear I don’t. I wish I did. I thought in camp we had terrific defensive practices. You look at the two exhibition games our defense was phenomenal against Toronto, who puts points on the board. Our offense was horrendous. Then we play the Knicks and Miami and score 104 and 100 and whatever and shoot 53 percent and we can’t get any stops. That’s what makes this job crazy.”

The first three games weren’t just bad by Celtics standards, they were horrific. They came into Friday night’s game next to last in defensive efficiency and field goal percentage defense and they were putting teams on the free throw line at an alarming rate. All of that speaks to bad rotations, tired legs and yes, a lack of communication and awareness.

The Pistons may have been the perfect opponent to get back on track. Former Celtics assistant Lawrence Frank is in the very early stages of trying to transform the franchise and they spent the majority of the night jacking up jump shots and curiously avoiding center Greg Monroe who scored 22 points on just 12 shots.

But give the Celtics credit. The Pistons may have willingly played into their hands, but this was strong, if not vintage, Celtics defense. Garnett was especially active hedging ballhandlers and recovering quickly to take away the next pass. 

“The first three games our offense wasn’t good and our offense contributed to help the other team score and defensively we put ourselves in bad situations,” Allen said. “They both weren’t good. Defensively we get on a similar chord where everybody knows where they’re supposed to be and we talk through it. That takes a while.”

All that positive defensive energy flowed into the offense and the Celtics produced a box score that was comfortably familiar. Five players took eight or more shots and no one attempted more than eleven. They shot 52 percent and had assists on 25 of their 35 made field goals. Best of all, they only turned the ball over 10 times.

Pierce played just 23 minutes, but his presence was felt from the start. “Just having Paul, space is so different,” Rivers said. “It was amazing how the ball moved today again.”

Despite their dreadful start, the Celtics have an opportunity to make up ground quickly. They have back-to-back games with the woeful Wizards and then a home date with the Nets whose only win came against Washington. From there they play a rather absurd 16 of the following 21 games at TD Garden. This is the time to put together a solid run.

“Tonight was a step forward but our first three games I thought we were very porous,” Allen said. “We have more steps to take. Getting all those pieces together and organizing, that’s important because everybody is going to be integral to our success. It’s going to take everybody to help us win games.”

Allen’s right. It will take everybody. From Brandon Bass and Keyon Dooling to the rookies. At some point everyone on the roster is going to have to contribute something meaningful if the Celtics are going to survive the season. But if they are going to prosper it will have to be with their four All-Stars on the court together speaking their native tongue.