“Advanced” Stats Tutorial, Part 2 – Rebounds, Assists, & Turnovers

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Published: October 23, 2012

In Part 2 of this Advanced Stats Tutorial, we examine the statistics related to rebounding, passing, and ball-handling.

If you missed Part 1 where I addressed the main statistical categories that pertain primarily to scoring, you can check it out here.

 

Rebound Rate (Comparable “Traditional” Stat: Rebounds per game)

Explanation: The problem with a statistic like rebounds per game is that it is entirely at the mercy of the amount of shots made and missed. For example, if a team made every single one of its shots in a given game, it would finish with 0 offensive rebounds. Does this mean that team is a poor offensive rebounding team? Not at all, but if one was to look at the team’s offensive rebound total in a vacuum, what other conclusion could possibly be drawn?

Therefore, a much better method to analyze a team’s rebounding skill is by weighing its percentage of rebounds collected against all available rebounds. This can be done for defensive rebounds (DRR), offensive rebounds (ORR), and total rebounds (TRR). In the 2011-12 NBA season, the league average was a 73% defensive rebound rate and a 27% offensive rebound rate (logically, the total rebound rate average was 50%).

Example of Impact: In the 2011-12 season, the Miami Heat ranked 21st in the NBA in rebounds per game with 41.6, but their total rebound rate of 51.14% ranked 6th in the NBA. Conversely, the Minnesota Timberwolves’ 43.7 rebounds per game may look nice (tied for 5th in the NBA), but their 50.2% total rebound rate ranks them 15th in the NBA and proves that they were merely an average rebounding team last year.

2011-12 Hornets: 24th in total rebounds per game (41.1), 12th in total rebound rate (50.7%). This total is comprised of an offensive rebound rate of 27.5% and a defensive rebound rate of 73.1%, both slightly above the league averages. Much like the Miami example above, it would be unfair to use rebounds per game to properly grade New Orleans’ team rebounding ability.

 

Assist Rate (Comparable “Traditional” Stat: Assists per game)

Explanation: Assist rate is a pace-adjusted metric that allows us to quantify how effective a team is at putting teammates in a position to score. It does this by comparing a team’s assist total to its total number of possessions instead of merely looking at a per-game total.  A ranking near the bottom of the league in this area is not necessarily a bad thing, but more often than not, the best teams in the NBA will have some of the higher assist rates (the top 5 teams in this category were Boston, Denver, San Antonio, Chicago, and Atlanta).  More than anything, though, this statistic is simply a tool that can be used to evaluate how an offense is typically run. In the 2011-12 NBA season, the league average assist rate was 19.83%.

Example of Impact: In the 2011-12 season, the Boston Celtics crushed everyone in this statistic with an assist rate of 23.45%, almost 1.5% ahead of the 2nd place Nuggets. or comparison’s sake, move down another 1.5% in the rankings and you’re completely out of the top 10. Given Ray Allen’s spot-up shooting, Kevin Garnett’s post game, and Rajon Rondo’s passing ability, this should not come as a huge surprise. Conversely, the Heat and Thunder finished 20th and 30th respectively, a testament to each team’s heavy reliance on the isolation game of their superstars.

2011-12 Hornets: New Orleans finished 12th in the NBA with an assist rate of 20.3%, which is a bit higher than their assists per game ranking of 16th (20.7 per game). With the additions of Anderson, Davis, a healthy Eric Gordon, and a more pass-first starting PG in Greivis Vasquez, it will be interesting to see in which direction the Hornets move this season.

 

Percent of Field Goals Assisted

Explanation: First, it is important not to confuse this stat with assist rate. Percent of field goals assisted measures, as the name indicates, what percentage of a team’s made shots are converted as a result of an assist, as opposed to the percentage of a team’s total possessions that contain an assist. This statistic is much more useful on a player level than a team level, as it allows us to look at how good players are at creating their own shots vs. relying on teammates to facilitate scoring opportunities. In the 2011-12 NBA season, the league average percentage of field goals assisted was 57.52%.

Example of Impact: The New York Knicks’ 3-point specialist Steve Novak led qualifying NBA players with 95.7% of his field goals coming via an assist, while Steve Nash led the league in the opposite direction with just 15.6% of his made shots coming as a result of an assist.

2011-12 Hornets: Jason Smith was the New Orleans Hornet most reliant on distribution help from teammates, with 80.7% of his total made field goals coming via an assist; Ayon and Belinelli were both close behind. On the flip side, Jarrett Jack required the least help for his made shots, as only 27.1% of them came with the help of an assist. If Eric Gordon can stay healthy, expect him to replace Jack in that regard.

 

Turnover Rate (Comparable “Traditional” Stat – Turnovers per game)

Explanation: Turnover rate is another pace-adjusted statistic that weighs a team’s total turnovers vs. its amount of possessions. In the 2011-12 NBA season, the league average turnover rate was 13.8% for teams and 14.6% for players*).

Example of Impact: The Sacramento Kings ranked an average 13th in the NBA in turnovers per game with 14.4, but once that number was adjusted for pace via turnover rate, their rank improved all the way to 5th (12.97%).

2011-12 Hornets: The Hornets’ turnover numbers were not pretty, finishing with a turnover rate of 15.19%, good for second worst in the league.

*Note – there is a difference in the average turnover rates for teams vs. players because not all team turnovers are are attributed to a single player (an example of this would be a shot clock violation).

 

In the third and final part of this series, we’ll dive into defensive stats and then look at a couple all-encompassing metrics as well. Just like before, if there are any questions that still loom after reading this post, please post them in the comments below so that I can continue to make updates to the column. All stats courtesy of HoopData.com, a part of the ESPN TrueHoop Network.

4 comments
GerryV
GerryV

Hornets DEFENSIVE EFF ranked #16....so now you see how PACE clouded the defensive numbers...I've preached PACE as a factor for several seasons.

Mason Ginsberg
Mason Ginsberg

Huge supporter of this outlook as well, along with the majority (probably all) of us here at H247. Went into detail in regards to off/def efficiency in part 1 on Saturday (linked at the top). Appreciate the feedback, sir!

GerryV
GerryV

I've been using certain advanced stats for years now...they can be tempting and fun to use but,never forget about the artful aspects of the game...I have a rule i use."if you need more space than the front of a small index card to evalute a player,the evaluations is to wordy"....also if a team lacks legit 3-Ballers they will die in the NBA.....nice work my friend.

Phelpsalot
Phelpsalot

Awesome job. Clearly explained. Fairly quick read. Advanced stats really don't lie!

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