Ryan Knaus

The Numbers Game

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NBA Stats: In the Zone

Monday, August 11, 2014


The locations of shot attempts are key for an NBA team's offensive and defensive efficiency, yet their impact on fantasy statistics is mostly invisible. My recent columns have used Synergy data for shot types (e.g. spot-ups, pick-and-rolls) and related data for points per possession. Today's column enriches the picture by incorporating shot locations as found on NBA.com:

 

  • Restricted area
  • In the paint (outside of the restricted area)
  • Mid-range (outside of the paint, inside the 3-point arc)
  • 3-pointers

 

At this sleepy stage of the season in mid-August, I'm discerning patterns of success or failure rather than a microscopic view of fantasy values. I took a 'microscopic' view last week and will do so again in the near future, and the information below is particularly useful in daily fantasy leagues where half of the battle is deciphering the most favorable matchups.

 

Note: When I discuss league-wide data about the "percentage of attempts" taken in a given shot zone (e.g. 32.4 percent of the league's attempts came in the restricted area), I am not weighting the percentages by volume of shot attempts. I instead average all 30 team's percentages allowed, which should prevent faster-paced teams from skewing the data away from slower-paced teams. The numbers reflect shot attempts only, so (unless noted) there's no consideration of possessions which ended with a turnover or free throws.

 

I opted not to include full spreadsheet data in the column, as it would be unwieldy, but you can view or download the data by following this link. That includes a sheet in which I have separated out these 'shot zone' stats by NBA divisions, which I did in the hopes that it would show clear disparities that could be exploited by the savviest fantasy owners. A player on the Nets, for instance, will play 16 games vs. other teams in the Atlantic division (the 76ers, Celtics Knicks and Raptors) and a total of 52 games vs. their own conference, compared to 30 games vs. the opposing conference. There's definitely something to be said for such an analysis, but my preliminary attempts didn't yield too much of interest...so I'm providing it on Dropbox without commenting on it in today's column. Oh well.

 

Opponent shots in the restricted area

 

The restricted area on an NBA court encompasses a four-foot radius from the center of the hoop. Shot attempts from this range are therefore extremely high-percentage, chock-full of layups, dunks, and chances following offensive rebounds. The divide between shooting percentages in the restricted area vs. other parts of the court is starkly evident in the chart below, referencing season-total stats for the 2013-14 regular season:

 

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Source: NBA.com

 

Keep in mind that a team's ability to 'defend the paint' may not be reflective of their ability to defend the restricted area, since many opportunities from this optimal range are the result of fastbreaks rather than half-court plays. The 76ers, who led the NBA in fastbreak attempts both for and against, are a great example. Whereas 34.1 percent of the shots Philly defended came in the restricted area, ranking 7th-highest in the NBA, they defended shots in the paint at the lowest rate of any team (11.8 percent). Opponents had no cause to take shots in the paint when Philly's defense was putting up zero resistance toward/at the rim.

 

Curiously, the Warriors were almost the exact opposite. Their opponents took a league-low 28.5 percent of their shots in the restricted area vs. Golden State, but they also took a league-high 18.5 percent of their shots in the paint. Andrew Bogut's anchoring presence helped to dissuade penetration during the 67 games he played in last year, and (as the chart above shows) the ability to limit opportunities in the restricted area is what matters most.

 

In this light, the Kings, Cavaliers, Pacers, Magic, Grizzlies, Bulls and Spurs were also highly effective, preventing opponents from attempting more than 30 percent of their total shots in the restricted area. By eliminating chances for easy buckets, the ability of these teams to defend shots at the rim (which varies widely) becomes an almost secondary concern.

 

The opposite is true for the Lakers, Pelicans, Celtics, Bucks, Jazz, Pistons and aforementioned 76ers, all of whom allowed at least 34 percent of their opponents' shots to come at the rim. It should come as no surprise that all seven of these teams ranked in the bottom-12 for defensive efficiency last year. There is simply no way to play effective defense when opponents are taking more than a third of their shots in the restricted area.

 

Just how powerful are shots in the restricted area? Those seven teams I just mentioned, which allowed the highest percentage of attempts in the restricted area, were also the seven teams which allowed the highest overall FG percentages to opponents last season. In this case, correlation most certainly implies causation.

 

There is more to the story, of course, and it's worth examining how well teams protected the restricted area once opponents got there -- about a third of the league's shot attempts came from this range, so it's not uncommon.

 

The Pacers were a case study in effective interior defense. In addition to ranking 27th in restricted-area shots allowed, they limited opponents to just 53.0 percent shooting in those situations (the league's overall average was 61.4 percent.) Easy buckets were very hard to come by vs. Roy Hibbert and company. The other hardest teams to score against at the rim (by FG percentage) were the Thunder, Blazers, Bulls, Bobcats and Spurs. The most lenient teams were the Cavaliers, Pelicans, Lakers, 76ers, Mavericks, Timberwolves and the last-place Kings (against whom opponents shot 65.1 percent in the RA).

 

The Kings are an interesting case, yielding the second-fewest attempts at the rim to their opponents, but allowing the highest shooting percentage once they got there. They also struggled to defend the paint and the 3-point line, resulting in a bottom-10 defense, and their personnel never allowed coach Mike Malone to establish his preferred defensive identity. I've argued that the problem may be exacerbated by the replacement of Isaiah Thomas with Darren Collison.

 

Opponent shots in the paint (excluding restricted area)

 

Shots located in the paint but outside of the restricted area were not an efficient way to score in the NBA last season. This shot type accounted for about 15 percent of all attempts (unweighted to negate the impact of pace), yet only 39.1 percent of those shot attempts were successful. It was no more efficient than mid-range shots and far worse than shots at the rim or beyond the 3-point arc -- in other words, shots in the paint were among the least efficient ways to produce offense in 2013-14.

 

The Knicks defended the paint better than any other team, holding opponents to just 35.5 percent shooting, followed closely by the Bobcats, Rockets, Lakers and Thunder. The Knicks' defensive efficiency was spoiled to some extent, however, since they did a poor job forcing opponents to attempt shots from this range (they ranked 28th, ahead of only the Bucks and 76ers). The easiest teams to score against were the Mavericks, Jazz, Hawks, Heat and Wizards, the last of whom allowed a league-worst 43.6 percent shooting in the paint (which is still pretty low in the overall context of NBA offenses).

 

I noted in a recent column, NBA Offenses by the Numbers, that post-ups accounted for 9.6 percent of all offensive possessions last season (the fourth-most-common play type). They only yielded an average of 0.86 points per possession, however, making them a relatively inefficient play type. David West, renowned for his post-up proficiency, managed 0.97 points per possession on post-ups last season, ranking in the top-30 across the NBA. That's still lower than the NBA average for spot-ups (0.98 PPP), pick-and-rolls ending with the roll man (1.01 PPP) and cuts (1.2 PPP).

 

Opponent shots from mid-range (outside the paint, inside the 3-point arc)

 

After the all-powerful restricted area, the largest chunk of NBA shot attempts (26.8 percent) happened in the mid-range -- as noted a few weeks ago, pick-and-rolls and spot-up attempts were (by a wide margin) the most frequent type of possessions in the NBA last year. The mid-range proved to be an inhospitable region for NBA offenses, however, producing no better shooting percentages than the non-RA paint just discussed -- teams shot a lousy 39.1 percent in both areas.

 

The five most efficient teams from the mid-range all had transcendent individual players capable of creating their own offense -- the Mavericks (Dirk Nowitzki), Thunder (Kevin Durant, Russell Westbrook), Clippers (Chris Paul, Blake Griffin), Heat (LeBron James, Dwyane Wade) and Knicks (Carmelo Anthony). And yet the Mavs' league-leading FG percentage from the mid-range was still a paltry 42.8 percent. The least efficient teams were the Nuggets, Pistons, Timberwolves and the league-worst Rockets, who made only 34.5 percent of their shots from mid-range.

 

Given the inefficiency of this play type, it comes as no surprise that some of the league's best defenses forced their opponents to take copious mid-range shots -- the Spurs, Pacers and Bulls ranked 4th, 2nd and 1st, respectively. On the other side of the ledger, the Knicks, Heat, Pelicans, Mavericks and Pistons did a poor job of forcing low-percentage mid-range shots from their opponents.

 

I've been driving home the inefficiency of shots anywhere outside of the restricted area but inside of the 3-point arc. This is perhaps nowhere more evident than the Spurs' hyper-efficient shot charts from the NBA Finals -- in a five-game span, they attempted a mere 36.7 percent of their shots from these two inefficient zones. Meanwhile, 30.7 percent of their attempts came in the restricted area and a whopping 32.5 percent came from beyond the arc.

  

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Their 52.8 percent shooting was the best Finals performance since the introduction of shot clocks in 1954. The ability to make so many shots is ultimately what matters, but the heady locations of those shots, set up by brilliant passing, should be given due credit. Gregg Popovich won Coach of the Year for a reason.

 

Opponent shots from beyond the 3-point arc

 

"Because there are no fours" - Antoine Walker, when asked why he'd led the NBA in 3-point attempts for three consecutive seasons

 

Walker's famous quote may prove prescient, as NBA teams have come to rely on 3-pointers for an ever-increasing share of their offense (see the Spurs' Finals shotchart above). The extra point awarded makes shots beyond the arc (especially from the wings) more appealing than any play type outside of the restricted area, and teams have taken notice -- The New York Times pointed out that NBA teams averaged a record 20 three-point attempts per game during the 2012-13 season, the same year Stephen Curry sank an NBA-record 272 triples.

 

Cavaliers' opponents were particularly inclined to launch triples last season, as they accounted for 30.3 percent of all shot attempts vs. Cleveland. Other teams to face routine 3-point barrages included the Knicks, Heat, Thunder and 76ers. The Heat and Thunder were decent at defending 3-point shots, which ameliorated the impact of so many efficient attempts, but they weren't in the same class as the Celtics, Pacers, Warriors, Suns or league-leading Clippers, who limited opponents to just 33.2 percent shooting beyond the arc.

 

The best defense, in many cases, is preventing 3-point shots in the first place. This doesn't show up as an obvious statistic, but some of the best NBA defenses also faced the fewest 3-point attempts last season -- the Blazers faced the fewest (20.7 percent of their opponents' attempts), followed by the Spurs, Pacers, Bulls and Celtics. I mentioned above that the Pacers and Celtics held opponents to a low FG% when they did attempt 3-pointers, making their perimeter defense doubly formidable.

 

Note that I'm lumping together 3-point shooting data, which NBA.com has separated into three categories -- above the break, right wing and left wing. Using individual categories can provide some interesting details, such as the Trail Blazers' far greater defensive efficiency vs. left-corner 3s (35.7 percent) than right-corner 3s (43.8 percent). It will be useful during the season, when gauging how an individual player or team will fare against a particular team's defense, but it's not worth diving into for the purposes of this column.

 

I should note that 3-pointers from the wings accounted for only 6.7 percent of the league's shot attempts last year, compared to 19.2 percent from above the break. This has been a consistent trend for years and occurs despite the much-improved odds of making a shot from the wings (see the 'Team FG% by Zone' chart above). The top of the arc is longer, more spacious and serves as the setting for many more picks and passes than the wings, so the disparity makes sense. Another reason for the increased above-the-break attempts (and the lower percentages) is that NBA.com must include half-court heaves without differentiating them from attempts taken in the course of a team's natural offense.

 

Follow me on Twitter @Knaus_RW for occasional updates, stats, etc.

 

I'll end here, though there's more I can say, and I encourage you all to explore the full spreadsheets to glean more insights for yourself. I'm not sure what I'll touch upon in future columns, as I'm shifting into gear for our upcoming NBA Draft Guide, the fruit of summer-long efforts by Rotoworld's entire NBA crew.

 

Speaking of which, Rotoworld's football staff returned this year's NFL Draft Guide for a touchdown. Kudos to Adam LevitanEvan SilvaPatrick DaughertyMike ClayChet GreshamNick MensioJeff RatcliffeRaymond Summerlin, and everyone else I've neglected to mention. The NFL Draft Guide costs just $14.99, a steal for anyone serious about winning their leagues, and there's currently a promotion to get both the Rotoworld Draft Guide & Season Pass for free via our partner Fanduel.com (when you deposit at least $15, which is the cost of the DG alone).



Despite residing in Portland, Maine, Ryan Knaus remains a heartbroken Sonics fan who longs for the days of Shawn Kemp and Xavier McDaniel. He has written for Rotoworld.com since 2007. You can follow him on Twitter.
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