Midway through last August, Jayson Tatum’s path toward earning enough playing time to have a meaningful nightly impact was unclear. Boston Celtics President of Basketball Operations Danny Ainge had built a roster loaded with interchangeable wing talent, and it would have been understandable if the 19-year-old Tatum was occasionally sacrificed as the odd man out.

But in the coming months, the depth along the wing grew unexpectedly shallower. Three-and-D specialist Jae Crowder was shipped to Cleveland. Gordon Hayward suffered a freakish broken leg. Marcus Morris, who had missed only three games since 2013, was sidelined by a nagging knee injury for half of Boston’s first 44 games. All of a sudden, a path to 25-plus minutes per night opened up at the combo forward spot, and Tatum was thrust into a situation that he could not have possibly foreseen when he was drafted.

In 29 college games and six summer-league contests, Tatum dazzled with turnaround fadeaways and delightful dribble step-back combinations. His highlights made for clickable YouTube videos, but the appeal of his offensive repertoire came with some unsettling concerns. Could a back-to-the-basket isolationist with mild ball-stopping tendencies thrive within the confines of head coach Brad Stevens’ pass-happy offensive scheme? Could he adjust from being the go-to option at Duke to a more off-ball centric role alongside Boston’s high-powered weapons? Could he refine his shot selection and reduce the number of low-percentage contested field-goal attempts?

The universal answer: an astounding yes.

Through 47 games, Tatum is averaging 13.7 points and 5.5 rebounds on 31 minutes per contest. Most notably, his production is coming at an impressively efficient clip. He sports shooting percentages of 56.5 effective field-goal rate, 46.0 from behind the arc and 81.7 from the charity stripe. He leads all rookie starters in net rating at 7.3 (minimum 30 starts).

According to data collected by NBA Math, Tatum ranks fourth in total points added (TPA) among all rookies and sophomores. TPA measures a player’s offensive and defensive impact on a per-possession basis, and it also accounts for the amount of playing time the player receives. His TPA (55.25) is almost twice as high as any rookie other than Ben Simmons and Jordan Bell.

The genius behind Tatum’s expeditious development is the way Brad Stevens has utilized him. Cautious about not overloading the rookie’s plate, Stevens has shown patience in developing Boston’s young offensive dynamo. The forbearance is paying off. Tatum is conquering every new task thrown at him, so the Celtics continue to spoon feed him more responsibility.

According to tracking stats by Cleaning The Glass, Boston is a top-10 team in points per 100 possessions in half-court sets. Stevens preaches the use of rapid ball movement to shift opposing defenses from side to side, thereby creating beneficial attack lanes. Having capable catch-and-shoot threats who force their defenders to pay the price for helping off them is a critical element for floor spacing.

To begin the season, teams rightfully prioritized their defensive attention toward Kyrie Irving’s ball handling and Al Horford’s pinpoint passing. Tatum was wholly unproven at that point. He had demanded fourth- or fifth-option priority, which opened up opportunities for him to flourish as a catch-and-shoot beneficiary.

Tatum already possesses a mature understanding of NBA-level spacing and is consistently making anticipatory shifts to set up easier passing lanes for his catch-and-shoot jumpers. In the below clip, he recognizes that the painted area is oversaturated with all five Orlando Magic defenders. As Horford attacks the rim, Tatum simultaneously pops out to the wing, knowing the defense will have to collapse.

Typically, crisp read-and-react skills like this necessitate a lot of playing experience, but Tatum already finds avenues to exploit spacing weaknesses in rotating defenses. According to Synergy Sports, 60 percent of his catch-and-shoot attempts are unguarded. While a portion of that luxury is attributed to his teammates creating shots for him, his knack for locating open gaps behind the arc helps the offensive flow.

After shooting 34.2 percent from distance at Duke, Tatum has jumped his rate to 45.1 percent this season.  Per Synergy Sports, Tatum ranks in the 92nd efficiency percentile on spot-up jumpers, and he’s already solidified himself as Boston’s go-to shooter off whom defenders cannot help.

Tatum’s striking three-point efficiency has become a common talking point, but the Celtics have continuously added different offensive facets to his role. Through November, 43.3 percent of Tatum’s field goals had come on possessions where he made zero dribbles, per NBA.com. That rate shrunk to 35.1 percent in December and is at 32.1 percent so far in January. The decline indicates that Tatum is actively diversifying his strengths beyond spot-up shooting, which will ultimately make him harder to scheme for.

Once Tatum grew into a known focal point,  opposing coaches began to plot against his shooting prowess.  The natural progression was to expand his versatility by developing a one-dribble pull-up jumper. He does a nice job attacking overzealous closeouts and accepting what the defense gives him. Analytics gurus might say mid-range jumpers aren’t sexy, but the combo-forward consistently opts for open two-pointers over contested three-balls. He ranks in the 92nd percentile in medium-range jump shots, meaning shot distances falling between 17 feet and the three-point line.

Despite Tatum’s success when defenders run him off of the three-point line, he can only be confronted with so many undisciplined closeouts on a given night. Stevens had to devise more offensive sets to harness Tatum’s innate ability to knock down mid-range jump shots. By running off designed screens, he can be freed up for open looks without having to bypass a defender.

Below is a simple set the Celtics run for all their top scorers. The design calls for the Celtic big to catch an initial pass along the wing, then swing the rock to the corner. The big (here: Horford) follows the pass to set a screen. Because the distance from the wing to the corner is relatively short, the shooter is able to get his jumper off with only one dribble:

By hiding Tatum off-ball and in the corner to begin the play, the defense is less inclined to smother him with attention. It’s a tactic Stevens has used to earn easy looks for Irving and Isaiah Thomas when opposing defenses are zeroed in on trapping.

Horford and Aron Baynes are skillful screen-setters and both rank in the top 35 in screen assists. Their frontcourt pairing with Tatum has produced Boston’s best offensive rating of any lineup (minimum 45 minutes played). Horford, specifically, is one of the better dribble-handoff bigs due to his adroit passing skills and ability to pop out for three-pointers. As Tatum continues to grow his overall court vision, he and Horford could present some terrifying mismatches in the two-man game.

Few players can effectively create their own shot on a consistent basis.  When offensive schemes aren’t working, having a dynamic playmaker on the floor can turn the worst possessions into a bucket.   According to Synergy, 22.8 percent of Tatum’s shots at Duke came in isolation. That frequency was never going to translate into his rookie season. Irving, for example, has shot only 15.1 percent of his field-goal attempts in isolation this season. Tatum sits at a palatable 9.4 percent, but the one-on-one specialist we saw last season is beginning to resurface.

Tatum shows a remarkably tight handle for a player of his size and length. He uses his 7’0″ wingspan to channel elongated crossover dribbles that help him shake defenders off balance. Hesitation pull-up jumpers like the one above have become commonplace for Tatum. Because of his beneficial length, he only necessitates a little bit of daylight to get a quality look.

His dribble-pull up is particularly hard to defend because he’s equally efficient going in either direction: Per Synergy, he calls on his pull-up jumper 36 percent of the time when driving right, and 39 percent when driving to the left. An even scarier aspect? He can do it against defenders of all sizes. In the above clip, he leaves Jrue Holiday in his dust, and in the below, he creates enough room to shoot over Joel Embiid’s outstretched arm:

Compared to last season, he infrequently calls on the back-to-the-basket turnaround jumpers we grew accustomed to last season and in summer league. Getting fewer post-ups (only 0.5 per game) has negated some of the ball-stopping and shot-selection concerns that accompanied him at the beginning of the season.

Success breeds confidence, and Tatum continues to show more self-assurance as the season progresses. For a 19-year-old rookie, calling for your teammates to clear out to afford you an entire side of the floor requires some serious conviction. By choosing to bypass the offensive set, you’re essentially saying you don’t need help to exploit your defender’s weaknesses.  So Tatum chooses his spots wisely.

Watch here as he pinpoints a mismatch against lead-footed Amir Johnson and directs his teammates to the other side of the floor:

As a playmaker, Tatum has much more room to grow. Creating a shot for himself comes as second nature, but generating quality looks for his teammates would make him truly dynamic. He averages an underwhelming 1.3 assists per game.

Perhaps his distribution statistics may be slightly skewed by Boston’s unique rotation, which includes four natural point guards (Irving, Marcus Smart, Terry Rozier and Shane Larkin) and an elite passing center in Horford, who averages 5.3 assists per contest, but he has the foundation to become a serviceable facilitator.

His wonderful shooting abilities evidence an advanced comprehension for team spacing, so being able to mentally invert his role to become a facilitator should come in time. As defenses continue to focus in on Tatum’s scoring, he could counteract by authoring more assists for open teammates. Physically, his deft handle allows him to weave through defenders of all sizes, and at 6’8”, he has enough size to make precise skip passes over outstretched arms.

As a prospect, Tatum was heralded as a scoring machine, but his lanky wingspan and quick-footedness offer unique switchability on the defensive end. As the league continues to amalgamate concepts of traditional positions, Stevens has admitted he now characterizes players into three groups: ball-handlers, wings, and bigs. Listed at 205 pounds, Tatum’s frame still has room to fill out, and while he may not yet have the physical tools to bang with the strongest wings, the statistics suggest that he’s blossoming into a promising two-way player.

He defends pick-and-roll ball-handlers in the 83rd percentile, shots off screens in the 74th percentile and spot-ups in the 69th percentile. Those play types constitute two-thirds of his total defensive possessions according to Synergy. The Celtics almost always switch on picks, and Tatum’s versatility as a stopper should eventually allow him to pester different kinds of scorers.

Tatum landed with a historically sound defensive unit in Boston. Its 99.7 defensive rating is tops in the league, and only five other teams have produced a better defensive rating during this decade. Like-sized Jaylen Brown gets the toughest wing assignments every game. Horford is one of the more intelligent traffic-directors in the business. The pesky duo of Rozier and Smart wreak havoc on opposing ball handlers. Baynes has the second-best defensive rating in the league (minimum 15 games played). Mix it all together, and Tatum simply needs to coexist on a squad that can block out the sun on most nights.

But that’s not to say the rookie isn’t challenged with the occasional tough endeavor. I wrote earlier this month about how Tatum was instrumental in shutting down James Harden during a 25-point comeback win in late December. Watch here as he uses his length to block the Beard’s patented step-back jumper late in the fourth quarter. Notice how he jumps to Harden’s side in order to prevent committing a cheap foul:

Tatum’s seamless transition into fitting with a contender has been astounding. He fills a multitude of different roles for the Celtics. He has now played 18 more games in the pros than he did in college. The rookie wall typically hits sometime in January, but he’s not showing signs of slowing down. While his role continues to expand, his efficiency hasn’t faltered. He ranks eighth in usage rate on the team but is second in offensive rating and third in scoring average, per Basketball-Reference.

Every once in a while, you need a reminder that Tatum is only 19-years-old.

His game oozes with maturity and sophistication. Stevens’ initiatives to spoonfeed him more responsibilities has been brilliantly orchestrated.  Mentally, reading-and-reacting to defensive schemes is atypical for most newcomers, but skeptics who were dubious about his willingness to abandon the negative habits from college have been quickly silenced.

Follow Matt Chin on Twitter @MattChinNBA.

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Statistics are accurate as of all games headed into January 22, 2017. All non-cited statistics are from Basketball-Reference.com or NBA.com. All salary information is from RealGM.com.