This is an extremely well-written article. How does net rating take into account faster offenses (quick shooters) vs. slower ones?
« NBA Advanced Statistics Abbreviations Glossary
“Advanced” Stats Tutorial, Part 1 – Scoring
The statistical measures that are used to evaluate NBA players are evolving; utilizing the Hornets’ 2011-12 season, let’s take a look at what everything means and where the team needs to improve going forward.
For a few of you, this column may include explanations of stat categories about which you’re already familiar. To those people, I salute you for being a fan who is substantially ahead of the curve. To the others, allow me to introduce a group of statistical measures that have not yet become mainstream, but certainly will be before long. At Hornets247, we consistently aim to provide our readers and fellow New Orleans Hornets fans with the best insight that we can in order for them to be the most informed NBA followers around. What follows is yet another step in making that goal a reality.
The funny thing about these so-called “advanced stats” is that most of them really are not that advanced in nature; “advanced” is simply a fancy word for “more accurate.” These alternate metrics simply take standard NBA statistics – points, rebounds, assists, etc. – a step further. Most basketball fans understand the concept of efficiency; for example, scoring ten points on five shot attempts is clearly more beneficial than scoring ten points on ten shot attempts. Advanced statistics are all about efficiency; how much does each player contribute (or take away) from his team while he is on the court? We can use the metrics that follow to get a pretty good idea. Each advanced stat category is followed in parentheses with the closest comparable “traditional” stat category.
Offensive Rating (Comparable “Traditional” Stat: Points Scored per game)
Explanation: The intuitive reaction to a team that scores lots of points per game is to assume that team has a potent offense. In reality however, this assumption is not always the case. A team could be scoring a ton, but if that team jacks up a shot within five or ten seconds in every possession, its point total could be quite misleading. Therefore, the best way to truly gauge a team’s offense is by utilizing a statistic called offensive rating, or offensive efficiency. The premise is simple; instead of looking at the team’s points per game, we instead add up the points that team scores per 100 possessions. This way, no matter how quickly or slowly a team runs its offense, they will all be evaluated equally. The 2011-12 league average offensive rating was 101.8.
Example of Impact: In the 2011-12 season, the Milwaukee Bucks finished 5th in the NBA in points per game with 99, while the Chicago Bulls came in 18th at 96.3. However, the Bucks were 15th in the NBA in offensive efficiency, scoring 102.4 points per 100 possessions, well behind the Bulls, who ranked 5th at 104.5 points per 100 possessions.
2011-12 Hornets: 29th in PPG (89.6), 26th in offensive efficiency (98.3). Therefore, the Hornets’ offense was actually more efficient than their points per game would indicate. 2011-12 League average: 101.8
Defensive Rating (Comparable “Traditional” Stat: Points Allowed per game)
Explanation: This stat is basically the exact same thing as offensive efficiency, except on the other side of the ball. A team that gives up a lot of points may seem like a bad defensive squad, but in reality it could just be a function of a fast-paced offense that allows for more possessions. By utilizing the amount of points allowed per 100 possessions, we can get a better indication of the defense’s actual ability. Logically, the league average for defensive rating was the same as the league average offensive rating – 101.8.
Example of Impact: In the 2011-12 season, the New Orleans Hornets finished 7th in the NBA in fewest points allowed per game with 93.4, while the Oklahoma City Thunder came in 17th at 96.9. However, the Hornets were 16th in the NBA in defensive efficiency, allowing 102.3 points per 100 possessions, well behind the Thunder, who ranked 9th at 100 points per 100 possessions.
2011-12 Hornets: As indicated above, the slow pace that the Hornets employed on offense helped to make their defense look better than it actually was. Their defense was not bad by any means, but it was not a top-10 unit like points allowed per game may have made it seem.
Net Rating (Comparable “Traditional” Stat: Points Scored – Points Allowed)
Explanation: A team’s net rating is just its offensive efficiency minus its defensive efficiency. Simply put, a positive net rating should indicate an above average team, while a negative net rating should indicate a below average team.
Example of Impact: Over on At The Hive, Rohan analyzed the net ratings of the past 20 NBA finalists and determined that for a team to reach the NBA finals, it typically needs to achieve a net rating of around +6.
2011-12 Hornets: The Hornets finished the 2011-12 season with a net rating of -3.98, which placed them 24th in the NBA.
Effective Field Goal Percentage (Comparable “Traditional” Stat: Field Goal Percentage)
Explanation: The goal of this statistic is simple – to account for the added benefit of making a 3-point shot. Using 2-point shots as the standard, eFG% weights every made 3-pointer as 1.5/1 instead of the traditional 1/1. The 2011-12 league average eFG% was 48.7%.
Example of Impact: Look no further than the 2011-12 Orlando Magic. As a team, they shot 44.1% from the field overall, which ranked 21st in the NBA. However, after adding in the increased value of a 3-pointer, they shot up all the way to 4th with an eFG% of 50.6%, a clear indication of their prowess from long range.
2011-12 Hornets: The Hornets finished 13th in FG% at 45.1%; however, their league ranking of 21st in eFG% (47.6%) properly displays their struggles with the 3-pointer relative to the rest of the NBA. For more detailed information, Jake Madison recently reviewed these struggles.
True Shooting Percentage
Explanation: TS% takes eFG% a step further, accounting for not only 3-point shots, but free throw attempts as well. True shooting percentage is very valuable as an all-encompassing scoring statistic; players who can both knock down 3-pointers as well as get into the paint and draw fouls are properly rewarded for their ability to create efficient scoring opportunities. A team with a low TS% in comparison to its FG% and eFG% typically needs to either get to the free throw line more often or convert on a higher percentage of its free throw attempts. The 2011-12 league average TS% was 52.7%.
Example of Impact: By measuring only FG%, you would be led to believe that the Timberwolves were atrocious, finishing 27th in the NBA at 43.3%. However, Minnesota’s TS% tells a different story; at 52.4%, they ranked 18th in the NBA, just .3% below the league average TS%.
2011-12 Hornets: Another bad stat for the Hornets here; their TS% was 22nd in the NBA at 51.7%, eight spots below their traditional FG% of 45.1%.
Free Throw Rate (Comparable “Traditional” Stat: Free Throw Attempts per game)
Explanation: As with any “per-game” statistic, results can often be skewed based on varying paces at which NBA teams play. A much more reliable metric to determine how effective a team is at earning free throw attempts is to weight it against the amount of shots the team takes. This concept is precisely what free throw rate does – all you have to do to calculate it is divide a team’s total free throw attempts by its total field goals attempted. This stat can also be utilized from a defensive standpoint to determine how prone a team is to giving up free throw attempts. The 2011-12 league average free throw rate was 27.6%.
Example of Impact: The Milwaukee Bucks attempted the 19th most free throws per game, averaging 21.4. Their free throw rate, however, was fifth worst in the league at 25.0%.
2011-12 Hornets: This stat is actually one that helps the Hornets out. Their free throw attempts per game average was tied with Phoenix for 21st in the NBA at 21.2. Their free throw rate, however, was 27.4%, good for a tie for 15th in the NBA and only slightly below the league average. Look for this number to improve this season, especially if Eric Gordon can remain healthy.
In Part Two of this series, we’ll look at some of the other advanced metrics for some of the non-scoring stat categories. If there are any questions that still loom after reading this post, I strongly encourage you to post them in the comments below so that I can continue to update this piece and make it as reader-friendly as possible. All stats courtesy of HoopData.com, a part of the ESPN TrueHoop Network.
Hopefully the league starts pushing advance stats so it's more apart of the game. Although I'm sure they prefer the regular stats because it's easier for the layfan to follow even though there are extremely deceptive.
Since offensive and defensive rating are both determined using a pace-neutral method, net rating will inherently do the same, as it is merely the difference between the two. Good question, though.