NBA Rookie Efficiency Rankings: The Return of Ben Simmons

Rookies are exciting. They bring hope and energy to floundering teams while also providing a glimpse of what future the league may hold. First-time players in the NBA routinely struggle to adapt to the pace of the professional game, but there are always a few standouts every year who look and play like seasoned vets from the start.

Our rookie rankings here at numberFire are not subjective or influenced by the latest hype -- we put our faith and trust in our algorithms. Every two weeks, we’ll list the top five rookies in the Association based on our nERD metric, which measures a player's contributions based on efficiency, and indicates how many wins above or below .500 a player would make an average team over a full season. So while names like Lauri Markkanen, Donovan Mitchell and Lonzo Ball are in the conversation for Rookie of the Year Award (and rightfully so), you won't see them below, because their high volume of minutes and usage ultimately has rendered them less efficient, statistically speaking, than the players listed here.

To make sure we only include players regularly contributing to their team, we are limiting ourselves to considering rookies averaging at least 15 minutes per game.

Let's dive into the most efficient rookies with our top-five players of the 2017-18 season so far.

5. Ben Simmons, Philadelphia 76ers

nERD: 0.9
Previous Rank: NR

The front-runner for the Rookie of the Year hardware, Ben Simmons leads all rookies in minutes played (35.1), rebounds (7.9), assists (7.3), and steals (1.8) per game. The Philadelphia 76ers' point guard is putting together a historic campaign, joining Oscar Robertson and Magic Johnson as the only three rookies ever to average at least 16.0 points, 7.0 rebounds, and 7.0 assists per game. Despite his impressive ability to pile up the counting stats, Simmons has been absent from our efficiency ranks due to his turnovers and shooting percentages.

For the season, the Sixer is averaging 4.0 turnovers per game (sixth-most in the NBA) with a 19.9% turnover percentage. His shooting woes at the line (56.1%) and lack of an outside shot (0-for-10 from three) tank his efficiency, as well. While he is shooting 52.7% from the field, fourth among qualified rookies, his true shooting percentage is lacking (53.9%), where he sits 16th among first-time players.

Over his last four games, though, Simmons has tightened up his game. He is committing only 2.0 turnovers per night (11.0% turnover percentage) while shooting 74.5% from the field. The rook is still piling up the numbers, averaging 20.8 points, 4.3 rebounds, 6.5 assists, and 1.3 steals per game.

4. Jarrett Allen, Brooklyn Nets

nERD: 1.2
Previous Rank: 5

Jarrett Allen has started to create a buzz in Brooklyn. The 22nd overall pick in the 2017 draft has finally seen a significant bump in playing time, moving into the starting lineup the last two games. The big man has rewarded the Nets' faith by stringing together five consecutive double-digit scoring games despite only playing just over 20 minutes per game.

During the stretch, Allen has been on fire from the field, sinking 25-of-30 shots (83.3%) for an average of 12.4 points. His last time out, he tied a career-high with 16 points by going 5-for-6 from the field and 6-for-6 from the line.

It hasn't been all about the points for Allen, either. The center has averaged 7.6 boards per game, leading the rookie class (fourth among all NBA players) with an 18.9% offensive rebound rate since January 23rd. The big man also recorded the first two double-doubles of his career, including an impressive 16-point, 12-rebound performance in a win over Joel Embiid and the Sixers Wednesday.

3. Bam Adebayo, Miami Heat

nERD: 2.3
Previous Rank: 4

With the Miami Heat frontcourt healthy for what seems like the first time this season, Bam Adebayo has seen his minutes decrease, but the rookie big man remains a vital part of the rotation. He is averaging just 19.7 minutes per game over the last two weeks, but has been one of the most effective players when on the court.

In those eight games, Adebayo has stuffed the stat sheet posting per-36 numbers of 11.6 points, 9.6 rebounds, 4.8 assists, 1.4 steals, and 0.9 blocks. He owns a top-five rebound percentage among first-timers during this stretch. He has also made his presence felt on the defensive end, as he leads all qualified NBA players with a 90.7 defensive rating since January 17th.

His finest game of this span came against the Charlotte Hornets and future Hall of Fame big man Dwight Howard. In a four-point Heat victory, Adebayo filled the box score with 8 points, 12 rebounds, 1 steal, and 1 block in just 25 minutes of action.

2. John Collins, Atlanta Hawks

nERD: 3.4
Previous Rank: 2

One of the NBA's best rebounders -- among all players, not just rookies -- John Collins has really started to flex his muscle on the glass lately.

In his last seven games, the Atlanta Hawks' big man is averaging 8.3 boards in only 21.7 minutes per game. That translates to 13.7 rebounds per-36 minutes, ranking him 11th among all NBA players to play at least 150 minutes the last two weeks. He is posting an impressive 13.7% offensive rebound rate for the season, placing him sixth among NBA players with at least 20 minutes per game. Naturally, Collins is at the head of the rookie class in offensive and total rebound rate, but his standing as top dog among first-timers in shooting efficiency has him knocking at the door of our top spot.

Posting a top-10 NBA rank in field goal (59.6%), effective field goal (60.4%), and true shooting percentage (63.7%), Collins has been one of the most efficient rookie scorers. He is averaging 17.3 points per-36 minutes, a top-five mark among rookies. The scary part is he is getting even better -- after attempting and missing just four three-pointers his first 32 games, Collins has gone 5-for-11 (45.5%) from deep in 2018.

1. Jayson Tatum, Boston Celtics

nERD: 4.7
Previous Rank: 1

One of the best rookies defensively this season -- his 98.9 defensive rating outpaces all other first-year pros - Jayson Tatum appears to have a hit a wall offensively in the last two weeks.

In his first 45 games played, the 19-year-old was shooting 49.9% from the field, 46.0% from three, and 82.3% from the line for 13.8 points per game. Since January 18th, though, his accuracy has plummeted, sinking to 40.7% from the floor, 32.0% from deep, and 70.0% from the line. It could be fatigue as Tatum, who exerts a ton of energy as one of the Boston Celtics' top players on both ends of the floor, has already played in 52 games and ranking in the top 30 of all NBA players with 1,613 total minutes.

Tatum may have seen the gap close, but he still outranks all other rookies in win shares (5.4), defensive win shares (2.9), and nERD (4.7) while placing second in VORP (1.5) and third in win shares per 48 minutes (.161).