Efficiency Ratings: N. Carolina

Using an NBA Efficiency Rating Formula, TDD tracks the best statistical performances of the season

A quick way NBA coaches measure a player's game performance is by evaluating his efficiency. In order to find a player's efficiency the following formula is used:

((Points + Rebounds + Assists + Steals + Blocks) - ((Field Goals Att. - Field Goals Made) + (Free Throws Att. - Free Throws Made) + Turnovers)).

For example, compare the following stat lines:

Player A: 17 points (5-of-22 FG, 7-9 FT), 8 rebounds, 6 assists, 3 steals, 4 turnovers.

Player B: 15 points (5-8 FG, 3-4 FT), 4 rebounds, 7 assists, 2 turnovers

Latest Game:

Tyus Jones and third-ranked Duke kept the pressure on North Carolina, scoring over and over until the Blue Devils had finally wrested away control of a tight rivalry game.

It was a show of both their toughness as well as the offensive potential of a team carrying plenty of momentum into the postseason.

Jones scored 17 of his season-high 24 points in the second half and the Blue Devils shot 59 percent after the break to beat the 19th-ranked Tar Heels 84-77 on Saturday night.

Quinn Cook added 20 points for Duke (28-3, 15-3 Atlantic Coast Conference), which capitalized on a couple of key turnovers by the Tar Heels (21-10, 11-7) to finally get a fragile hold on a road game in which neither team could get many second-half stops.

The latest rivalry renewal was a competitive fight throughout, with UNC shooting 58 percent after halftime but unable to catch up once Duke finally got the game turned with about 6½ minutes left on the way to its 11th straight win.


(change from previous game)
  • Jahlil Okafor +15 (+8)
  • Justise Winslow +11 (-16)
  • Tyus Jones +34 (+19)
  • Quinn Cook +16 (+16)
  • Amile Jefferson +5 (-9)
  • Grayson Allen +4 (-24)
  • Matt Jones +3 (-13)
  • Marshall Plumlee +0 (-9)

Notes: Jones’ big day was the second best performance of any player this season, and was the best score of any Duke player against a power conference opponent this year. The freshman scored, shot well from the field and free throw line, rebounded well, and had a 7-to-1 assist to turnover ratio. It all resulted in a +34, which is the highest score a guard has ever posted in the five years we’ve kept the efficiency ratings.

Duke also got a lift from Cook and Okafor at various spots with the senior guard posting a +16 and Okafor adding a +15.

In an admission that the formula doesn’t always tell the complete story, Amile Jefferson’s +5 seems extraordinarily low as did his +.161/minute rating. However, anyone who saw the game would not the captain’s contributions in disrupting shots, cleaning up the boards, and doing a number of blue collar things that really seemed to change the game when the big three were on the bench.


Throughout the season TDD will track the various highs and lows using the formula.

Ten Most Efficient Performances

  • Jahlil Okafor v. Elon (+37)
  • Tyus Jones v. North Carolina (+34)
  • Jahlil Okafor v. NC State (+33)
  • Jahlil Okafor v. Furman (+32)
  • Jahlil Okafor v. Boston College (+32)
  • Jahlil Okafor v. Virginia Tech (+30)
  • Amile Jefferson v. Furman (+30)
  • Jahlil Okafor v. Wofford (+30)
  • Justise Winslow v. Syracuse (+29)
  • Grayson Allen v. Wake Forest (+28)

Five Least Efficient Performances*

  • Justise Winslow (-5) v. Miami
  • Rasheed Sulaimon (-4) v. Temple
  • Grayson Allen (-3) v. Boston College
  • Matt Jones (-2) v. Elon
  • Amile Jefferson (-1) v. Clemson


Cumulative Season ratings for the Blue Devils. (E/game)*
  • Jahlil Okafor +644 (21.5)
  • Tyus Jones +487 (15.7)
  • Quinn Cook +472 (15.2)
  • Justise Winslow +433 (14.0)
  • Amile Jefferson +353 (11.4)
  • Matt Jones +196 (6.3)
  • Marshall Plumlee +143 (4.8)
  • Grayson Allen +98 (3.6)*

*- Games Factored In: Allen (27); Okafor (30)


Cumulative Season ratings per minute for the Blue Devils. (E/minutes)
  • Jahlil Okafor: 0.698
  • Amile Jefferson: 0.512
  • Marshall Plumlee: 0.491
  • Justise Winslow: 0.485
  • Tyus Jones: 0.475
  • Grayson Allen: 0.447
  • Quinn Cook: 0.424
  • Matt Jones: 0.312


Tracking the most and least efficient performances by player
  • Jahlil Okafor 37 / 7
  • Amile Jefferson 30 / -1
  • Quinn Cook 27 / 6
  • Tyus Jones 34 / 1
  • Grayson Allen 28 / -3
  • Justise Winslow 29 / -5
  • Marshall Plumlee 17 / 0
  • Matt Jones 17 / -2


- Jones’ performance against North Carolina pushed him into second place behind Okafor for the season standings. The only drama in the season standings appears to be whether or not Cook and Jones will continue to swap places.

- Despite his tapered off production over the last month and his relegation to the sixth man role, Amile Jefferson is still Duke’s second most efficient player per minute.

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