It is forever the basis for any win, while the blame after every loss — and even some victories — goes directly to that side of the ball. Coach Doc Rivers is fond of saying that the team will go only as far as its defense takes it.
But you still have to put the ball in the hole.
And with the way Boston has been doing that of late, it might be time to shine a little light on that end of things.
In Friday's 105-87 win over Oklahoma City on Friday night, the C's wrapped up a 4-0 road trip and continued a stretch of offensive basketball worth noting.
The Green shot 56.5 percent from the floor, made over half of their 3-point attempts and put seven players into double figures. It was the fifth time in seven games the C's topped the 100-point mark, which rests above their season average.
Their 31-point first quarter was a season high and they were at 88 by the time the third quarter ended. Finally there was a bit of a bend in the old company line.
"We really shot the ball well," Rivers said. "I actually thought [Oklahoma City] defended some of the shots well and the ball went in. That happens."
It does, but you need the right parts to make it happen and during this hot stretch it has become clear that all are on hand for Rivers.
There are at least four regulars who can kill you from outside, two big men who seemingly never miss and a speedster on the point who can find any of them in the right spot after breaking down defenses like few players can.
Friday offered a perfect example of how an opponent is simply left to pick its poison.
Paul Pierce hit three straight 3-pointers in the opening four minutes en route to 21 first-half points. He was held scoreless in the second half, but Rajon Rondo and Kevin Garnett showcased a two-man game that broke open the game, combining for 24 points in the third quarter alone.
In the fourth, Rasheed Wallace and Eddie House hit the last few of the Celtics' nine 3-pointers (in just 17 attempts) to kill any dreams Oklahoma City had of making a comeback.
Pierce jokingly explained how it was all part of the game plan.
"I wanted them to get all their attention on me. I'm like a decoy," Pierce said of his big first half. "In the second half they thought I was going to come out aggressive and other guys start smacking it around like KG and Rondo.
"That's the versatility of our team and it's fun because I don't have to do it all game. We have so many guys that can step up."
Boston has shot 54 percent over its last five games. Garnett and Kendrick Perkins have combined to go a remarkable 71-of-88 from the floor in that span. The club entered Friday ranked second in the NBA in assists per game and third in shooting overall.
Both Pierce and Rivers, once pressed, did give credit to their defense again. Indeed, the Thunder looked lost at times. But with some of the aforementioned numbers to back it up, offense is finding its way into the discussion.
"Our defense has finally come back," Pierce said "I like the way we played in the last three games. We were able to hold teams, keep them under 100 points.
"And also score ourselves."