Allen is now on a team that's sitting at the top of the Eastern Conference and will definitely make a strong push for a spot in the NBA Finals, but the Boston Celtics may not be so lucky.
After coming within one win of a trip to the big dance last season, ironically in a game against the Heat, Boston is now 20-23 and eighth in the Eastern Conference playoff race.
Suddenly, Allen's decision to take his talents to South Beach doesn't seem like such a bad decision.
Things almost did not go down the way they did. Once Allen hit free agency, Celtics GM Danny Ainge offered him a two-year, $12 million deal to remain with the team as its starting shooting guard.
Seeing as how Allen had averaged 16.7 points per game and shot 41 percent from long range in five years with the Celtics, winning a championship and becoming the all-time leading three-point shooter along the way, fans assumed that loyalty would keep Allen in Beantown.
Sadly, that was not the case.
Allen instead accepted a three-year, $9 million offer from the Miami Heat to serve as their sixth man. The Boston fans' hearts were broken, and not even veteran Celtics big man Kevin Garnett would talk to Allen following his departure.
When the Heat and Celtics opened the 2012-13 NBA season on Oct. 30, Garnett made headlines when Allen walked over to shake his former teammate's hand before the game, only to be snubbed.
In that particular game, Allen proceeded to score 19 points off the bench as the Heat won 120-107.
All drama aside, it's clear that Allen left the Celtics at the right time. Upon his departure for Miami, Ainge went on to sign both Courtney Lee and Jason Terry. Both were solid three-point shooters, and it was assumed that Boston would be able to contend without Allen manning the 2.
Instead, Boston's production at shooting guard has been abysmal. Lee has been a complete disappointment, averaging just 7.3 points per game, and Terry's 9.8 points are his lowest since his rookie season. The combined three-point percentage of both men is just 35 percent, and Boston's collective three-point percentage is just 33.5 percent, 27th in the league.
As much as it may hurt some fans to admit it, Allen meant more to the Celtics' offense than they may have thought. Though the current roster is not that much different from last season's, the age of both Kevin Garnett and Paul Pierce has started to show.
The two of them can hold their own on offense, but Rajon Rondo is not strong enough a scorer to simply fill the void left by Allen.
In losing him, Boston lost a dynamic offensive player who could run off screens and catch-and-shoot three-pointers, both of which are critical in head coach Doc Rivers' system. Terry can shoot threes, but he is best suited to creating off the dribble rather than waiting for the ball and then shooting upon receipt. Lee can hold his own behind the arc, but is not a specialist by any means.
Boston fans can criticize him for leaving all they want, but the Celtics' performance says it all. The team misses Ray Allen and his consistently good production.
Speaking of Allen, he's sitting pretty in Miami as one of the league's most reliable sixth men. He's averaging 11.4 points over 25.5 minutes per game, and has shot an incredible 44 percent from beyond the arc. Not at all bad for someone who's 37 years old!
He may not ever be forgiven for leaving the Boston Celtics and signing with the team that kept them out of the NBA Finals in 2012, but one thing is certain. No matter how you look at it, Allen has definitely had the last laugh.