BOSTON, MA - MAY 23: Jayson Tatum #0 of the Boston Celtics handles the ball against the Cleveland Cavaliers during Game Five of the Eastern Conference Finals of the 2018 NBA Playoffs on May 23, 2018 at the TD Garden in Boston, Massachusetts. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. Mandatory Copyright Notice: Copyright 2018 NBAE (Photo by Brian Babineau/NBAE via Getty Images)

The 2018 rookie class was one of the best in recent memory, led by budding stars Ben Simmons, Donovan Mitchell and Jayson Tatum. In this era of analytics, there are now robust models that forecast the arcs of this trio for the next seven years, relying on aging curves and similarity scores to prognosticate offensive and defensive value in the ensuing seasons. But their development as passers might hold the key to the story.

In Year One, Simmons was already a dominant and dazzling playmaker; his future will certainly be shaped by the progress of his nonexistent outside shot. Mitchell was a dynamic slasher capable of setting up teammates.

Yet Tatum lagged behind as a myopic scorer. He was clearly the weakest distributor of the group, which surprisingly, might be the very reason he surpasses his classmates down the road.

Measuring passers

On one hand, simply comparing assists and shots created — passing “production,” if you will — might tell us how much rising stars like Tatum can grow as passers. The last four MVPs have led the league in box creation (an estimate of open shots carved out for teammates by drawing defensive attention) and the last 10 MVPs have placed in the top-six in creation. Every MVP since 2007 has averaged five assists per game. Table-setting is a hallmark of offensive superstardom.

Still, there’s more to passing than accruing assists. Sometimes great passers accumulate meager numbers due to role and team makeup, and sometimes marginal passers dominate the ball more, inflating their stat-line. In order to capture these nuances, I needed to look beyond production. I wanted to measure passing ability itself.

Fortunately, for my all-time player series, I began charting all kinds of passing tendencies. Armed with about 25,000 passing possessions from key players past and present, I recently whipped up a “passer rating” model that runs all the way back to 1978. The model includes turnovers, assist-to-load ratio and the percentage of assists that led to layups (available since 2002). There are even some interactions with height that boosted accuracy. Passer rating essentially falls on a 1-to-10 scale, with the ratings toward the very edges of the spectrum compressed in a nonlinear fashion.

To capture passing production, I scaled the passing components of offensive load to represent a player’s distribution volume. When paired with passer rating, this generates a nice snapshot of someone’s passing skills and role:

Production and rating correlate because some of the inputs overlap, but they also correlate because most coaches don’t ask subpar passers to orchestrate the offense. Conversely, there are many skilled passers who lack the overall ability to run an offense, so they effectively serve as valuable extra passers. The names and positions on that chart largely jibe with my intuition (and hand-tracking), but in order to forecast the fate of Tatum, the metric needs to capture changes within a player from year-to-year.

To smell-test this, I looked at a few players with notable passing evolutions. For instance, Karl Malone steadily improved as a passer over the years based on my film study. Here’s what his career arc looks like in passer rating and production:

Not only does passer rating sync up with Malone’s narrative, but his massive percentage of layup assists at the end of his career (when layup assists were available) paint him as a borderline elite distributor. Basically, players leave a passing footprint in the box score beyond the mere volume of their assists, and we can detect that signal pretty well, especially when comparing the player to himself. Which brings us back to Jayson Tatum.

Projecting Tatum

When Kobe Bryant entered the league, he already possessed the traditional bread-and-butter of a slashing guard — the ability to vacuum in defenders and drop off a short pass for a dunk. The year prior, at Lower Merrion, Kobe pointed the attack despite standing taller than most players on the floor, facilitating for teammates as overwhelmed defenses trapped or doubled him. Bryant was primed to read collapsing defenses, but most young scorers are not.

Tatum is no different. His isolation arsenal may be the most mature for a teenager since Kobe, but his eye-popping attacks come with tunnel vision; with his head down, Tatum is unable to fully punish defenses who react to his penetration. His passer rating checked in at 2.6 in 2018, in the 12th decile historically. Armed with these new passing metrics, we can now forecast how much precocious scorers like Tatum can improve their playmaking.

The former Blue Devil averaged nearly 23 points per 100 possessions as a rookie, so I looked at passing growth among 20-point seasons for players 21 or under, per Basketball-Reference’s date cutoff. (I only compared players with a seven-year career or longer to offset reverse survivorship bias.) The average growth among that cohort of 157 players, from rookie year to peak season, was 1.6 points in passer rating. Seventy-four percent of all wings from the cohort added at least a point to their passer rating at their peak, and 43 percent added 2 points.

But starting level makes a difference. Advanced passers, such as a young Chris Paul, have less room to grow; among players with an original passer rating of at least 6, average peak growth was only 1.2 points. So elite passers like Simmons will typically improve, but not by considerable margins.

Conversely, weaker passers like Tatum have far more room to grow. From that same cohort of 20 point (per 100) scorers, players with a rookie-year passer rating under 5 had an average increase of 1.7 points at their peak. The 15 worst perimeter passers of the bunch — with ratings from 1.8 to 3.5 — improved by an average of 2.5 points at their apex. So the safest bet, in a vacuum, is that Tatum peaks with a rating around 5. That would move him to the 64th percentile historically, right where Donovan Mitchell was last year.

While Mitchell was comfortably ahead of Tatum as a rookie passer, he was buoyed by his seniority. Mitchell is a year-and-a-half older than Tatum, and age also predicts how much further a player can improve his vision. The closer someone is to his mid-20s, the less he has to grow based on historical trends:

Passers with full careers often peak as passers in their thirties, after years of mentally encoding the game. Still unable to legally drink, Tatum is about as far away from his production peak (typically realized between 23 and 27) and overall passing peak as one can be, whereas Mitchell isn’t expected to improve too much more on his breakout opening year.

But those are merely averages — what about Tatum’s ceiling? Is it possible for a relatively weak passer to transform into an elite distributor? The most dramatic passing upgrade from a scoring wing since the merger came from Nicolas Batum, who has improved by 5.3 points in passer rating since his 20-year old rookie season. (Most of that improvement came overnight in 2013 when he transformed as a playmaker.) Batum’s rookie years is one of a dozen under-21 seasons close to Tatum’s 2018 based on passing and scoring, and that group improved by a whopping 2.9 points in passer rating and 1.7 points in production, including DeMar DeRozan’s 3.5 point increase in passing production:

Fittingly, of the young rookies similar to Tatum, Kobe Bryant peaked with the highest passing production (96th percentile historically). Catching Kobe as a passer seems unlikely, whereas a reasonable ceiling seems closer to, say, fellow Celtic Paul Pierce. Pierce posted a 4.0 passer rating as a rookie (with a production of 4.5), but he was nearly two years older than Tatum when he entered the league. He peaked at just under 6 in passer rating and slightly over 6 in production, and, given that 19-year old Tatum was comparable to 21-year old Pierce as a scorer, such passing heights could land Tatum on the cusp of offensive superstardom.

Simmons is already eagle-eyed, well ahead of where Tatum will ever be a a passer. He’s among the league’s best playmakers and it’s unlikely that his vision will improve significantly. Furthermore, his current free throw percentage and lack of an outside shot make it unlikely for him to ever develop into a respectable jump shooter, limiting his room for growth. Mitchell has more passing development in him than Simmons, but, given his age, his scoring attack has a lower trajectory.

There’s always the risk that Tatum overly focuses on isolation and that his passing never makes the leap. Every player matures differently, so any future forecasting should be chewed with a large grain of salt. But history (and age) are on Tatum’s side here. Based on similar rookie seasons, his scoring is headed toward the 99th percentile. His defense is already positive. And his passing growth gives him a great chance to go down as the jewel of the class.

Ben Taylor is the author of Thinking Basketball and the Backpicks GOAT, an in-depth examination of the 40 best careers in NBA history. You can find passer ratings for historical players on his website.