In December, on the eve of the one-year anniversary of the trade that sent him to the Boston Celtics, Jae Crowder noted how he said a little prayer for the opportunity the change in scenery afforded him. The Celtics executives, who acquired Crowder from the Dallas Mavericks in a blockbuster swap that shipped out All-Star point guard Rajon Rondo, probably thanked their lucky stars as well.

The Celtics were high on Crowder when he was acquired, but even they could not have fully anticipated the way he has blossomed here. A key part of Boston's second-half surge to the playoffs last season as a reserve, the Celtics re-signed Crowder to what now seems like a bargain five-year, $35 million extension this past summer, and he's rewarded them by finding another level as the starting small forward.

On Monday night, Crowder returns to Dallas for the first time since being traded away. He's offered nothing but praise for his time with the Mavericks, the team that plucked him 34th overall in the 2012 NBA draft and helped him develop into a rotation-caliber player. But with the Celtics, Crowder found a chance to fully showcase his talents, and there's a case to be made that he's been Boston's best two-way player this season.

The Celtics were high on Jae Crowder when he was acquired, but he has exceeded expectations. AP Photo/Michael Dwyer

"I woke up [on the eve of his one-year trade anniversary] and I said a prayer thanking God, thankful to be in this situation because a year ago I was a little lost in this league, so I’m very thankful," Crowder said last month.

Isaiah Thomas, another of Boston's midseason additions last year, remains the Celtics' best chance at an All-Star, in large part because of his importance to an anemic Celtics offense. But Crowder's impact should not be overlooked. He's putting up career-best numbers on the offensive end and providing gritty defense at one of the league's toughest positions.

As Celtics coach Brad Stevens noted recently, that's maybe the most noteworthy aspect of Crowder's play this season. Last year, he often thrived while playing a power forward role when Boston went small with reserve lineups. Those combinations were the key in propelling the Celtics to a 24-12 finish to the regular season and the seventh seed in the East. This season, however, the Celtics have rarely shifted Crowder from his small forward position and he's still thriving at both ends, even when the matchups are a bit more daunting.

Crowder ranks 23rd in the NBA in ESPN's real plus/minus metric. He elevates to 19th in RPM wins, an estimate of the number of wins a player has contributed to his team's total this season. At 5.45 wins, Crowder is six spots ahead of Thomas (4.71), while Jared Sullinger (47th, 3.55), Amir Johnson (52nd, 3.28), and Kelly Olynyk (64th, 2.75) are the only other players for Boston ranked among the top 150 in the league.

Among small forwards, a super competitive category topped by some of the NBA's biggest names, Crowder ranks sixth in both RPM and RPM wins behind only Kawhi Leonard, LeBron James, Kevin Durant, Paul George and Carmelo Anthony. Crowder is third among small forwards in defensive RPM trailing only Leonard and James.

Crowder is putting up career-best numbers across the board, thanks in large part to his increased minutes. After logging a mere 10.6 minutes per game in 25 appearances before being traded by Dallas last season, Crowder is now averaging 32.2 minutes per game this season. That's translated into career highs at 14.6 points, 5.2 rebounds, 1.9 assists, and 1.8 steals per game.

But the man that Boston fans have affectionately dubbed "Bae" Crowder -- and, informed of that nickname before the season, Crowder embraced it by noting, "So a lot of people have crushes on me? Men and women? Right on." -- has really kicked things up since the end of December.

In the 15 games since Crowder celebrated his one-year anniversary with Boston, he's averaging 18.4 points per game while shooting 49.5 percent overall and 35.4 percent beyond the 3-point arc. He's added 6.5 rebounds, 1.9 assists, and 1.6 steals over 34.3 minutes per game. During that same span, Boston owns an offensive rating of 109 while he's on the floor and, with a 100.8 defensive rating, Crowder owns a net rating of plus-8.2 points per 100 possessions, which is best on the team in that span.

None of which really hammers home exactly what has set Crowder apart in Boston. For as soft-spoken as he is away from the court, he's fire and brimstone on the floor. He's the nerve center of Boston's defense and often embraces the challenge of defending the opposition's top scorer.

Sometimes Crowder's intensity boils over, as it did twice recently. Crowder lashed out at teammate Marcus Smart for an ill-time frustration foul that hurt the team during a loss in Memphis (the two talked it out after the game) and Crowder picked up a bad technical foul while barking at Wizards coach Randy Wittman during Saturday's win.

Crowder atoned for his transgression in Washington by registering the winning basket in the final seconds. Along with Thomas, he's been one of Boston's more consistent players during crunch time while shooting 45 percent overall and 45.5 percent in clutch situations, or when the score is within five points in the final five minutes.

According to Synergy Sports data, Crowder is averaging a team-best 1.04 points per play offensively, which ranks in the 92nd percentile overall (and among players with at least 450 offensive plays this season, Crowder is 10th in the NBA via Synergy's data). Defensively, Synergy grades him out as middle of the pack (allowing 0.864 points per play, 50th percentile) but the league's player-tracking data notes that Crowder is limiting his opponents to 42.3 percent shooting overall, or 1.5 percent below their season averages.

For the season, Crowder owns a net rating of plus-6.4, which is best on the team. Further hammering home his importance: The Celtics own a net rating of minus-3.8 when Crowder is off the floor, the team's offensive rating dipping by nearly 10 points and the team's defensive rating elevating slightly. Only one other player causes Boston to have a negative rating when he's not on the floor: Avery Bradley at minus-0.1.

There are still plenty of areas for Crowder to improve upon. He must learn to create for himself off the dribble, especially on a Boston team where Thomas and Evan Turner are the only two players that consistently do that. Crowder's 3-point shot tends to be streaky and, as previously noted, he must prevent his emotions from boiling over.

But it's impossible not to recognize that Boston's turnaround started in large part when the Celtics swapped out Rondo for Crowder. It changed the personality of the team. Gone was a player who downshifted on defense and seemed content to rest on what he had accomplished; in came a player that was eager to prove himself and make defense his calling card.

Reflecting on Rondo's flameout in Dallas, Mavericks owner Mark Cuban noted last month in Boston that "s--- happens," and praised both Crowder and Dwight Powell for emerging as the best players in the deals when most considered them throw-ins.

The Celtics stand to collect Dallas' 2016 first-round pick (top-seven protected) in June to complete their haul. Boston didn't turn the other parts of the Rondo trade into much -- Jameer Nelson was moved to Denver to create some salary relief, while Brandan Wright fetched a protected Minnesota pick that will likely turn into a pair of second-round selections.

But Crowder was the prize. And for all he has done already, his best might still be ahead of him.