The NBA All-Star game is this weekend, which means we have an abbreviated week of NBA basketball. However, this is a great point in time to see how NBA rookies have performed at the unofficial midway point of the season. You’ll see that a certain oft-injured rookie remains at the top of the Rookie Power Rankings, but we have a number of new additions, as well.

Instead of using the latest hype to point out who is deserving of being one of the league's top five rookies right now, we're using math -- specifically nERD. This metric measures a player's contributions and is based on efficiency. This ranking gives an estimate of how many games above or below .500 a league-average team would win with that player as one of their starters

As noted last installment, we’ve lifted the requirement of a per-game average of 15 minutes so we can add in players who are beginning to take on more prominent roles with their respective teams.

Without further ado, let’s see who our top five rookies are at this point in the season.

5. Yogi Ferrell, PG, Dallas Mavericks

nERD: -0.4

Yogi Ferrell signed with the Dallas Mavericks nine games ago, and he’s been on fire ever since. This has been in stark contrast to when Ferrell struggled to find consistent playing time earlier this season with the Brooklyn Nets, who eventually waived him.

With the Mavericks, Ferrell has gone from a roster afterthought to a starting guard playing 34.7 minutes per game. He’s also producing with those minutes, averaging 15.2 points per game, 4.9 assists per game and 1.6 steals per game.

This opportunity could be temporary once the Mavericks have Jose Juan Barea, Deron Williams and Devin Harris healthy again, but Ferrell may force the Mavericks to find time for him if he keeps up his play. The Mavericks are clearly happy with Ferrell, signing him to a two year contract, so he certainly has a future in Dallas.

4. Ivica Zubac, C , Los Angeles Lakers

nERD: -0.3

Ivica Zubac is another new addition to our rookie rankings. Over his last 10 games, Zubac is averaging 17.0 minutes per game for the Los Angeles Lakers, and this has led to 8.2 points, 5.4 rebounds and 1.1 blocks per game.

That’s pretty good production for a 19 year-old who has only appeared in 22 games this season. The rebuilding Lakers will likely give Zubac more opportunities to show what he can do.

3. Juan Hernangomez, PF, Denver Nuggets

nERD: 0.7

Our third and final new addition to the rankings is Juan Hernangomez. He’s starting to play more significant minutes with the Denver Nuggets as they deal with a recent trade and various injuries to other frontcourt players such as Kenneth Faried.

Over Hernangomez’s last nine games, he’s averaged 17.8 minutes per game while contributing 8.1 points and 5.0 rebounds per game. However, during his last game against the Golden State Warriors, he played 43 minutes and put up 27 points (including 6 three pointers), 10 rebounds, 2 assists, 1 block and 1 steal.

He probably won’t play that much going forward, but he is carving out a meaningful role on an exciting young team.

2. Guillermo Hernangomez, C, New York Knicks

nERD: 0.7

Guillermo Hernangomez continues to produce for the New York Knicks. Over his last 10 games, he's seen 21.7 minutes per game, averaging 9.6 points, 9.3 rebounds and 2.0 assists while shooting 52.6% from the field in that span.

Given the Knicks recent record and dwindling playoff hopes -- they have a 5.5% chance of making the playoffs, per our models -- we may start to see a greater emphasis on developing their younger players. If that occurs, we can expect to see more of the Willy Hernangomez show going forward.

1. Joel Embiid, C, Philadelphia 76ers

nERD: 0.8

Since our last power rankings column, Joel Embiid has not played a single game due to an injury to his left knee, which will keep him out of NBA All-Star weekend.

That being said, nothing can take away from what Embiid has shown the NBA and its fans so far this season. He’s a 22-year-old rookie averaging 20.2 points, 7.8 rebounds, 2.1 assists and 2.5 blocks per game in just under 26 minutes per night.

The sky appears to be the limit here as long as he can stay on the court, giving the Philadelphia 76ers a franchise centerpiece.