Without Ray Allen, there is no Kevin Garnett. It wasn’t until Danny Ainge acquired Allen from Seattle in a draft-day trade – involving Jeff Green, in an odd twist – that Garnett began to relent on the idea of coming to Boston. That, along with the championship and the endless 3-pointers remains one of Allen’s most important contribution to the revitalization of a franchise that had grown stale and even worse, ordinary.

It was a shotgun marriage of sorts, bringing Allen, Garnett and Paul Pierce together. Their personalities couldn’t have been more different, but it was more perfect than any of them could have expected. Yet, each one allowed the others to function in their own little world and to flourish individually on the court, while not detracting from each other’s game.

The manic Garnett ran things behind the scenes. Pierce, salt of the earth that he is, took the up-front captain’s role, deflecting much of the daily public pressure associated with a team like the Celtics. Allen was the philosopher, holding court with writers at his locker each night, approximately 10 minutes before the locker room closed like clockwork.

On the court, they fit seamlessly. Pierce operated on the elbow and above the circle, taking the shots that needed to be taken and creating when everything else broke down. Allen worked the wings, running his mini-marathons each night around screens and creating motion and space. Freed from the responsibilities of scoring, Garnett was content to run the defense, which is his true genius.

Together they won almost 70 percent of their games, 11 playoff series, two conference titles and one championship in five years. Now, suddenly it’s all over.

Allen is gone, having taken his peerless jump shot to Miami to team with LeBron James and Dwyane Wade. In a way it’s a betrayal of what they worked for and accomplished together, but then Allen has always known that he’d be the one to go first.

More than anything, Allen craved control over his surroundings. That's why he showed up hours before every game at the same time to go through the same routine. That's why he took a two-year contract with an option after the 2010 season. But control was something he couldn't have with the Celtics.

Allen was almost traded in 2010 and again this past season just before he lost his starting job to young Avery Bradley. At the time, the team spun the demotion as Allen’s call, one more selfless move from a group that prides itself on sacrificing individual accomplishments for the greater good. But it wasn’t that simple and it was never Allen’s plan to come off the bench.

There have been hints and innuendo of a larger rift between Rajon Rondo and Allen and little things began to manifest themselves on the court. At times, Rondo would stare right through an open Allen on the wing and work the offense the other way. At others, Allen was the one player who didn’t heed Rivers’ instruction to always give the ball to Rondo after a rebound so he could start the break.

What became painfully obvious throughout the 2012 season was the Celtics’ offense had grown less dependent on Allen’s motion and long-distance shooting and was almost entirely reliant on Rondo’s slash and kick game. Garnett, as usual, adapted quickly and after some reluctance, Pierce did as well. Allen never seemed to find the happy medium and as his shot attempts went down month after month, so did his role within the offense.

Bradley emerged as not only a dynamic defensive player, but a crafty offensive force. His backdoor cuts opened up space just as effectively as Allen’s long runs around the perimeter and when Bradley developed a killer corner 3-pointer, the whole argument was over before it even started. Bradley made them a different team and a better one, as well.

Because he’s a pro, Allen accepted the change publicly and became a full-time reserve for the first time in his 16-year career. When Bradley’s shoulders went out, Allen moved back into the starting lineup and labored through 30+ minutes a night on painful bone spurs that required surgery as soon as the season was over.

The spurs affected Allen so much that it forced him to alter the mechanics on his perfect form. He poured himself into watching video and taking shot after shot in an effort to craft something that would work in games. The result was a rapid-fire release that was more line drive than his patented arc.

When the season ended it seemed like a foregone conclusion that he would leave, but then the Celtics made a strong effort to keep him. They offered him more money. They envisioned him and Jason Terry working together in a revamped second unit that would actually be an offensive threat instead of a liability. They let it be known in public and private that bringing him back was their main priority, but it wasn’t enough.

By adding Terry, a veteran scorer who can also create his own shot they have covered themselves. The question now is whether Bradley will be able to return from shoulder surgery and continue his rapid development.

The Celtics are still hamstrung by the restraints of the salary cap. Counting various cap holds and other mechanics, they are over the cap and once they re-sign Jeff Green they will be over the line in reality, as well as theory.

They can’t replace Allen through traditional means, but in a way, this makes Danny Ainge’s job easier. He’ll have the necessary space below the luxury tax apron to bring back Mickael Pietrus and Greg Stiemsma, who is a restricted free agent. This may also open the door for second-year guard E’Twaun Moore to earn a meaningful role.

Ainge could have the bi-annual exception – a two-year deal worth almost $2 million per season -- to lure another veteran free agent. They also retain the Bird rights on Nenad Krstic, who reportedly left his team in Russia. If they can stay under the tax entirely, they will also be able to make trades far more easily.

When the dust clears, the Celtics may have a more complete team without Ray Allen, but it won’t be the same. They were moving in that direction for most of the 2012 season anyway and now it’s official: the new Big Three era is over. Allen was the consummate pro while he was here and in one of the true upsets of the last five years, he ended it on his terms.