NBA Rookie Efficiency Rankings: Jordan Bell's Rise Continues

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 Ben Simmons, 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 so far 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-5 players of the 2017-18 season so far.

5. Maxi Kleber, Dallas Mavericks

nERD: 0.8
Previous Rank: NR

The 25-year-old undrafted big man from Germany has found a role alongside his hometown and childhood hero Dirk Nowitzki, as he has started alongside the Dallas Mavericks legend in the frontcourt for the last 23 games.

Since joining the starting lineup, Maxi Kleber has shown his versatility and usefulness to the Mavericks -- he can stretch the floor (32.7% three-point shooter), score down low with efficiency (71.2% shooter in the restricted area), and blocks shots (3 games with at least 3 blocks).

In his starting role, Kleber is averaging 6.8 points, 4.3 rebounds, and 0.9 blocks with a 61.0% true shooting percentage in just 21.7 minutes per game. One high note of his efficiency has been how careful he has been with the basketball. Kleber hardly ever commits a turnover, a rarity for a first-year player, with just 12 in over 600 minutes of action. That is less than 0.4 per game. He is only one of nine players this season to post at least a 13.0% usage rate while keeping their turnover rate to 7.0% or lower.

4. Bam Adebayo, Miami Heat

nERD: 1.5
Previous Rank: 3

In the last three weeks, Bam Adebayo has seen his minutes fluctuate due to the return of Hassan Whiteside. He has gone from playing a career-high 37 minutes in a win over the Mavericks on December 22 to less than 16 minutes in his last game action. The Miami Heat big man has averaged 9.1 points, 6.4 rebounds, and 2.1 assists in 26.8 minutes in the last 10 games played, with his best overall performance coming on December 18. In the game versus the Atlanta Hawks, he posted his second career double-double with 11 points, 10, rebounds, 1 steal, and 2 blocks.

Adebayo's most notable contribution to the Heat this season, besides providing valuable depth to an injury plagued frontcourt, has been his knack for setting screens. Recently the NBA started keeping track of what they call "hustle stats," with one category being screen assists. They are defined as screens for a teammate that directly lead to a made field goal by that teammate. Currently, Adebayo leads the Heat with 3.2 screen assists per game, which places him 18th among all NBA players -- veterans and first-timers alike.

3. John Collins, Atlanta Hawks

nERD: 2.1
Previous Rank: 2

In the early part of December, John Collins was forced to sit out six games with a sprained AC joint. He was averaging 11.5 points, 7.1 boards, and 0.9 blocks per game before the injury -- and hasn't missed a beat since coming back.

Over his last 10 games, the Hawks' big man has dropped double-digit points five times while posting a 60.0% true shooting percentage. But it's been his rebounding and rim protecting ability that has been the biggest asset to a rebuilding Hawks' squad. During the last three weeks, Collins is averaging 1.5 blocks per game, leading all rookies while ranking 13th among all NBA players. That's all while playing just 22.5 minutes per game. He has swatted at least 3 shots 3 times in his last 9 game, after pulling off the feat just once in his first 21 professional appearances.

Collins has been unstoppable on the glass as well. For the season, he is averaging 11.2 boards per 36 minutes and leads all qualified rookies, since December 14 in offensive (13.5%), defensive (23.2%), and total rebound percentage (18.1%).

2. Jordan Bell, Golden State Warriors

nERD: 2.3
Previous Rank: NR

OK, we're bending our rules a bit with this one. So far this season, Jordan Bell is averaging just 14.7 minutes per game, under our 15.0 per threshold, but since making his first NBA start on November 24, the Golden State Warriors' rookie is averaging 18.7 minutes per game, earning himself a pass.

Since his post-Thanksgiving start, Bell has arguably been not only the most exciting rookie, but also one of the best, according to advanced metrics. The man who was sold by the Chicago Bulls for $3.5 million on draft day ranks in the top four among all rookies in offensive, defensive, and net rating while ranking first among rookies with a 68.7% true shooting percentage. His all-around abilities fit perfectly alongside or replacing Draymond Green in the lineup. In his 9 starts this season, Bell is averaging 7.9 points, 5.9 rebounds, 3.7 assists, 1.2 steals, and 2.0 blocks in just 24.5 minutes per game while posting a plus/minus of 15.9 per game while on the court.

In his most recent game, Bell swatted 4 shots and dropped 11 points against the Memphis Grizzlies in just 18.5 minutes.

1. Jayson Tatum, Boston Celtics

nERD: 4.9
Previous Rank: 1

Just as he has all season long, Jayson Tatum continues to dominate the rookie ranks here. Nothing he's done in the last three weeks has forced him to drop from the top spot, as he is averaging 14.9 points, 5.3 rebounds, 1.5 assists, 1.0 steals, 0.7 blocks, and 1.0 threes over his last 10 games.

While other Boston Celtics ( Kyrie Irving and Al Horford) are all surefire All-Star candidates, Tatum is the glue that keeps Boston at the top of the Eastern Conference standings. Aside from Terry Rozier, he is the only Celtic to play in all 40 games this season, starting in every single one of them. While his three-point shooting has taken a hit recently (33.3% on his last 33 attempts), the rookie still leads the NBA with a 47.1% mark. Even with his shot from deep dipping from his ridiculously hot start to the year, Tatum has scored at least 18 points in three of his last four games, averaging 16.5 points since Christmas Eve.

An exceptional two-way player, Tatum ranks fourth in the NBA in defensive win shares (2.1) and 10th in true shooting percentage (64.1%). No wonder his nERD rank has him 14th among all players, ahead of Horford and other efficiency darlings like Nikola Jokic and Draymond Green. An impressive feat for anyone, not to mention a fresh faced rookie.