Nylon Calculus: Zion Williamson’s debut puts him in rare company

Zion Williamson finally made his NBA debut and needed just 18 minutes to make history and prove that he’s a star in the making.

Zion Williamson was certainly worth the wait.

Recovery from knee surgery delayed the debut of the No. 1 pick in last year’s draft by nearly three months, but Williamson immediately started making up for lost time. Wednesday night, in the first game of his career, Williamson needed just 18 minutes against the Spurs to pile up 22 points, 7 rebounds and 3 assists, shooting 8-of-11 from the field and 4-of-4 on 3-pointers. Perfect shooting from beyond the arc was the surprising cherry on top of the sundae but this performance had everything Pelicans’ and NBA fans could have hoped for — eye-popping efficiency and highlights born of his unique combination of strength, skill and athleticism.

While it was a huge moment for his career and the Pelicans‘ organization, the numbers he put up weren’t necessarily, on their face, historic. By Game Score, a box-score based measure of a player’s single-game contributions, it was just the 47th-best rookie debut of the 3-Point Era. The graph below shows all rookie debuts of the 3-Point Era with a Game Score of at least 10, charted by the player’s age in days.

Obviously a strong rookie debut doesn’t necessarily correlate with an incredible NBA career (we’re looking at you Michael Carter-Williams) but for a player as young as Williamson it looks slightly more impressive. If we chart Zion’s debut only against the other 69 teenagers to have played at least 15 minutes in a rookie debut in this era, he begins to separate from the pack.

The three at the top here are Lamar Odom, LeBron James and Anthony Davis.  The debut just slightly ahead of Williamson (get excited Pelicans’ fans) is Jaxson Hayes, who put up 19 points on 11 shots with 3 rebounds, an assist, a steal and a block in his first game earlier this season. But again, it’s a mixed bag — the three debuts immediately following Williamson’s are Jahlil Okafor, R.J. Barrett and Dennis Smith. In the top-15 here, you’ll also find Sasha Pavlovic and Dajuan Wagner.

However, there’s one more complicating factor. Game Score is a measure of raw production, it does not adjust for how many minutes or possessions a player was on the floor for during a game. Of the top-15 rookie debuts by teenagers here, Williamson is the only one to have played less than 20 minutes.

If we look at just rookie debuts by teenagers who played at least five but less than 20 minutes, Williamson is threatening to lap the field.

The second-best teenager rookie debut to have come in less than 20 minutes was the decidedly less impressive 7-point, 6-rebound, 1-assist, 2-steal and 1-block performance by Zaza Pachulia in 2003.

If you really want to take the full measure of Williamson’s debut, roughly double his stat line from this game to get the per-36-minute permutation — 43.3 points, 13.8 rebounds and 5.9 assists. Not every game will work out as well as this one and, just like any rookie, he’ll almost certainly hit some rough patches over the next few months. But after Game 1 of his NBA career, it’s clear that Zion Williamson is up to the challenge of delivering on his hype.