Avery Bradley began his career swimming upstream. A broken ankle kept him out of training camp. He was learning a new position on the fly, playing behind an All-Star point guard who averaged close to 40 minutes per game. Bradley’s coach Doc Rivers notoriously keeps rookies on a short leash, if he allows them any leash at all. And Bradley played on a veteran team whose one real goal was a championship, pushing the development of a raw rookie from the University of Texas to the back of the team’s to-do list.

When Bradley received any playing time at all, it was brief and far between. Defensively, Bradley still stood out. His knowledge of Boston’s schemes wasn’t ideal, but whenever Bradley’s opponent caught the basketball, Bradley tried his best to imitate a hungry pitbull attacking a piece of steak. Yet his offense was not nearly as refined or aggressive as his defense.

With the ball in his hands, Bradley played like a deer staring straight into approaching headlights, unnatural at his new point guard position, uncomfortable playing alongside Hall of Famers, unable to prove Doc Rivers’s perception of rookies wrong. The best NBA players carry themselves with a certain amount of grace — even Paul Pierce, whose game is more herky-jerky than most stars, flows from one move to the next, a strong dribble to his right seamlessly morphing into a stepback jumper or a strong finish at the rim or whatever other move Pierce’s mind might concoct. Bradley showed little or even none of that grace during his maiden professional season. His dribbles looked awkward, his shots appeared reluctant, and his moves, though we know otherwise, seemed unpracticed.

Some of the struggles were expected; as a freshman at Texas, Bradley — his game unpolished and jagged around the edges — failed to live up to his sizable high school hype. The Celtics knew they were taking a risk by selecting Bradley with the 19th pick of the 2010 NBA Draft, but it was a calculated one. Yes, he underwhelmed for the Longhorns. Indeed, there were other players more NBA-ready (Landry Fields, for one). But Bradley possesses physical traits that make scouts drool and he puts them to good use whenever he drops into a defensive stance. If and when Bradley develops ball skills to rival his defense, the Celtics know, Bradley will become a hell of a player.

If and when.

I have a theory about the development of young NBA players — a player’s growth relies as much on his mentality as it does on his talent. The NBA landscape is filled with wings who can jump into the air and stair straight into an eagle’s eye, shooting guards who can swish nine out of ten jumpers in a practice session, centers who are seven feet tall with 88-inch wingspans, point guards who can turn the light off and sprint out of the room before darkness takes over. Some of these players succeed in the NBA. Others don’t. Often, the difference between Gerald Green (golden body, tin foil brain, out of the NBA before the age of 25) and Ryan Gomes (semi-limited physical talent, plays his role without complaint, started 62 games last season) rests in the brain rather than the body.

Every player on the NBA’s radar possesses gifts; the ones who succeed are not always the ones who possess the greatest gifts. Gifts afford players an opportunity to play in the NBA, but professionalism and work ethic will maximize their success.

Of course, the maximization of success is relative. Vince Carter has scored 20,520 points, made eight All-Star games, and finished in the top-10 in scoring six times. Did he realize a greater portion of his potential than Kevin Ollie, who turned limited athletic ability and a scant jewelry box of skills into 13 NBA seasons, $20.1 million and now an assistant coaching gig at UConn? Or Eric Snow, who wouldn’t beat anyone in a race, couldn’t score 20 points in an empty gym, but still started 551 career games and always found a spot in the rotation? There is something about Carter that made him fall short of expectations, just as there is something about Snow and Ollie that allowed them to survive in the NBA longer than their skills normally would have dictated.

By all accounts, Avery Bradley is a bright, good kid. He’s humble and unassuming, and he impressed Boston’s coaching staff and veteran players with his work ethic. He plays hard, he works hard, and he yearns to improve.

“He’s a great listener,” said Rajon Rondo in November. “For a young guy to come in, he’s humble, and works extremely hard. He’s going to be a great player in this league one day, whenever he gets the opportunity.”

But for most of last season, Bradley looked like a devout Christian in a strip club, uncomfortable and out of place in his surroundings. The tools are there — the quick feet, long arms, and 40-inch vertical — but in the NBA, the tools are always there. Even Brian Scalabrine, whose name enters the “least talented NBA player” discussion, is 6’10 with range that extends beyond the three-point arc. The aforementioned Gerald Green had Tracy McGrady-ish talent, and he was out of the NBA and playing in Russia before the age of 25.

Bradley has a long road to travel before he realizes his potential — such a long road that at this point, we really can’t judge his ceiling. Maybe he has the talent to become a top sixth man, a defensive change of pace like Lindsey Hunter. Maybe he can become a starter. Maybe an All-Star. Maybe his rookie struggles were more indicative of Bradley’s game than we suspect and Bradley will struggle to remain on an NBA roster when his rookie contract ends.

Bradley’s rookie struggles were actually historic. He was a 20-year old rookie last season, putting him in the company of 36 other 19- or 20-year olds who were 6’4-and-under in NBA history. As you might have expected, Bradley’s numbers compare unfavorably to his fellow young guards. Bradley had fewer win shares during his rookie season (-0.5) than any 19- or 20-year old, 6’4-and-under guard since 1954 (stats via Basketball Reference).

Win shares are based on total statistics rather than per-minute stats, so Bradley’s lack of playing time hurts him in the calculations. A more accurate portrayal of his season can be found by comparing his per-36 minute statistics. Even this is not nearly perfect, as Bradley’s lack of playing time affected so much — i.e., he could not get a rhythm because he played so sparingly. Another reason even Bradley’s per-minute stats are skewed — Bradley played many of his minutes in garbage time, when the competition isn’t stellar and players don’t necessarily play their hardest.

Still, 36-minute projections allow us to compare Bradley’s season more accurately than total statistics.  And Bradley compares more favorably when the statistics are adjusted. (Note: I chose a handful of current players rather than including everyone from the previous list. For the full list, click here.)

Young guards, per-36 minute stats

As you can see, Bradley struggles in the areas we expect him to: his playmaking ability is almost non-existent and he shoots bricks more often than he should. But he scores at a clip similar to many young (and, later in their careers, successful) guards. When his scoring instincts blossom and become coupled with his defensive tenacity, Bradley could have a bright future.

Still, there are mountains to climb and seas to swim across before Bradley even becomes a rotation player, never mind an NBA star. He needs to learn how to run a team. He needs to spend all summer shooting jump shots. He needs to gain confidence in his ability.

Nobody sees Bradley as a finished product and, quite frankly, very little he accomplished last year offered much hope for his future. But the soon-to-be (or maybe not-so-soon-to-be) second-year guard has a humble propensity for work and a handful of elite athletic traits that could allow him to grow exponentially when given the opportunity and a little confidence.

“I think Avery’s going to have a good career,” former college teammate and current Denver Nugget Jordan Hamilton was quoted in yesterday’s Boston Globe.

The jury’s still out.