How Advanced Statistics & Analytics has Changed the NBA

Have you watched the NBA this season? On Saturday, April 6, the NBA broke the 3-point record again… for the seventh consecutive season. Teams are playing at a pace 4.1 possessions faster than last year, the second largest jump in NBA history (the largest jump was from the lockout shortened 1999-2000 season to the 2000-2001 season). Teams are now shooting more 3-pointers than free throws. Contrary to what Charles Barkley may think, analytics has had a hand in all of it. But exactly how has the growth of sports statistics and analytics in the NBA affected how the game is played?

72 years ago, the NBA was founded on June 6, 1946 and was originally called the Basketball Association of America (BAA). It merged with the National Basketball League (NBL) not long after, becoming the National Basketball Association, as it is known today, on August 3, 1949. Back in those days, and many seasons afterward, players were only evaluated using the “eye test”. The 3-point line was implemented beginning in 1979, the same year Larry Bird and Magic Johnson were first entering the league. The Celtics-Lakers rivalry got people interested in the game, and allowed the NBA to be as successful as it is today. “The sports market has grown over $12 billion over the last 5 years, and this growth will continue as the professional games become more and more competitive.” (Analytics Improving Professional Sports Today, pg 2). As the competition continues to get better and better, teams are looking for anything to give them even the slightest advantage: analytics.

Larry Bird and Ervin “Magic” Johnson

Modern quantitative basketball analysis was actually derived from Bill James’ book “Baseball Abstracts”, with basketball analysts taking some of these ideas and philosophies and creating their own relating to basketball. Early basketball analysts focused on “linear weights” statistics, which take values for key statistics to find a player’s total efficiency, usually on a per-minute basis. Analysts continue to create formulas that can accurately find a player’s total efficiency and value, although there is not one universal metric that is used to find this. Effective Field Goal Percentage (eFG%), True Shooting Percentage (TS%), and Player Efficiency Rating (PER) are some of the best ways to analyze a player’s true value today.

“Baseball Abstract” by Bill James (1982)

It wasn’t until the beginning of the 2013-2014 season that basketball statistics and analytics really started to grow. Why? This was the first year the NBA implemented “Player Tracking” technology called SportVU in all 30 of its arenas. Originally developed to track missiles, SportVU is six computer vision cameras up in the catwalks, three per half court, and the accompanying ICE software to track all ten players and the ball 25 times per second. The cameras record the X and Y coordinates of each player, and the X,Y, and Z coordinates of the ball around 72,000 times per game. This data allows teams to see how fast and how much a player moves, how much a player touches the ball, how many passes a player made, how many rebounding opportunities there were for each team and player, time of possession with the ball, player separation, and much more. Having all of this data available, teams must be able to interpret this data and use it in a way that most benefits the team and its players.

Using this newly available data, teams have identified the most important aspects of basketball to win in today’s game: 3-pointers are worth more than 2-pointers, faster pace means more possessions, defense (especially transition defense) still wins championships, and efficiency is more important than totals. Let’s start with the rise of the 3-point shot.

Since the beginning of the 2013-14 season, we have seen 3-point records being broken over and over again. The Houston Rockets just broke their previous record on Sunday, April 7 against the Phoenix Suns, hitting 27 three pointers in the game. The top ten teams with the most 3-pointers in a game can be found here. Then there are individual players shooting threes, with only 11 of the top 45 players in NBA history on the 3-pointers made in a game list doing it before the 2013-14 season. Stephen Curry, James Harden, Klay Thompson, and Kevin Durant are all on the NBA All-Time made threes list as well, with each of them having a chance to potentially end in the top 10 or higher in the history of the league. At number 3 already and having just turned 31 years old last month, Stephen Curry has a good chance to be the greatest 3-point shooter (and just shooter overall) of all time. That’s incredible!

“If you were a really good mid-range shooter, you might make 48-50% of your shots. If you were a below average 3-point shooter, and only made 33.3% of your deep balls, that was better than the best mid-range shooters.” (“Why NBA Game Pace Is Historically High“)

@kirkgoldsberry

Players have adjusted to this notion, as shown in this tweet above. In 2003-2004, LeBron James still shot a high frequency of threes from the corner (22 feet away, about 2 feet closer than any other three pointer), but he also shot a lot of baseline, mid-range jump shots. Comparing LeBron’s rookie year with Luka Doncic’s, we can see that Luka’s mid-range game is almost non-existent. However, the frequency of which he shot a 3-pointer, not including the corner three, significantly trumps LeBron.

@kirkgoldsberry

A more drastic example would be when comparing Allen Iverson’s highest scoring season of his career with James Harden’s highest scoring season (this season). Iverson did a lot of his damage in the mid-range, especially from the right side, but he scored only 3.0 points per game from the three point line. Compared to Harden’s season, 3.0 points per game from three point range is laughable. James Harden is scoring 14.1 points per game from the three point line, which is 39% of his overall points per game. Compared to Iverson’s 9% of his overall points coming from threes, you can clearly see that the 3-pointer is as important as ever.

@kirkgoldsberry

Looking at the figure above, we can see that there is a direct correlation between the implementation of SportVU and the increased percentage of three point shots taken. For the 2013-14 season, we can see that there was a significant jump in three pointers taken by centers, although it gradually decreased for two seasons before making another spike. From the 2.1% of shots taken by centers being 3-pointers in 2012-13 to 12.7% in 2017-18, we can see that a 10.6% increase over only five seasons after relatively no change at all before the 2012-13 season is significant. Power forwards have seen the most drastic increase in the percentage of their shots taken being behind the arc. From 2010-11, when only 11.9% of shots taken were threes, to 2013-14, when around 15% of shots taken were threes, we can see a gradual increase. However, from 2013-14 to 2017-18, the percentage of 3-pointers taken rose from about 15% to 32%. That’s more than double in only four seasons! The last big jump comes with shooting guards, with around 36% of their shots coming from distance in 2013-14 to 43.6% in 2017-18. This is a pretty big leap for a position where shooting threes has always been a requirement (since the 3-point line was introduced). Point guards and small forwards have not seen any drastic changes since the 2013-14 season, although they both continue to rise gradually. Big men like Brook Lopez, Kristaps Porzingis, Al Horford, Nikola Mitotic, Karl-Anthony Towns, Anthony Davis, Dirk Nowitzki, and many more have expanded their game out to the 3-point line in recent seasons. Other bigs that have not developed their three point shot, such as Andre Drummond, Deandre Jordan, Rudy Gobert, and Clint Capela, have become somewhat one-dimensional. They stay relevant because of their talent on the boards, on the defensive side, and/or their ability to finish around the rim. Big men with lesser talent that have yet to adapt to today’s NBA have either seen their roles reduced or have been out of the league all together.

@xschelling

“In 2018-19, players are making early 3’s at a 37.3% rate, whereas the more patient variety splash home at a 35.5% rate. That’s why it’s called ‘pace and space’.” (“Why NBA Game Pace Is Historically High“)

I have played basketball my whole life, and whenever the NBA starts to change, there is a trickle-down effect on how the game is played in college and high school, as well as how little kids play. When I was a freshman in high school, I decided to join Integrity Hoops with some of my teammates, which is a summer basketball training program that lasts for eight weeks, five days a week for 2-3 hours a day. I played basketball with Integrity Hoops for all four years of high school, and I could see how the game was changing based on the types of shots players were taking and the types of drills we were running. For example, when I first started Integrity, they would break up the guards and the big men and work on completely different drills. While the guards were working on dribble moves, shooting, and spacing, I was working with the big men on post moves, defending without fouling, and finishing around the hoop. Then at some point one of the groups would go do a workout that included lifting weights, doing squats and lunges, box jumps, etc. while the other group scrimmaged, and then we would switch. I remember my last year at Integrity being much different, as we would no longer split up into groups to work on big men drills. Everybody would work on dribble moves, shooting, and spacing, and we would no longer break off to do workouts while the other group scrimmaged. The change coincided with the change in the NBA, with shooting threes and sprinting the floor becoming a priority over setting up an offense in the half-court and looking to get the ball in the paint.

This leads us to the second largest change in the NBA since “Player Tracking” became a league-wide tool: pace. Pace is just the number of possessions a team has per game.

Pace is orange ; 3-pointers are blue
With pace increasing, players are more likely to get back on defense rather than go for the offensive rebound
Starts during the 1973-74 season because that was the first year offensive and defensive rebounds were recorded separately (needed to calculate pace)

Teams have realized that a faster pace of play means each team ends up having more possessions per game. And more possessions per game means more shots per game. And where there are shots, there are usually points. From 2007-2011, Tom Thibodeau’s defensive schemes were dominating the league, as his teams would play a zone with a lot of help defense. The plan was to keep the opposing players out of the paint and force them into a bad, mid-range jumper. This was successful, so the league started to adjust. And the easiest way to beat his scheme was to forget about the mid-range and start jacking up the long ball. This was the beginning of the rise of the three-pointer and the rise of pushing the pace, even though “Player Tracking” helped these concepts really explode into what they are today.

During my time playing basketball in high school, I remember being a sophomore and playing on both the Junior Varsity and Varsity teams. Our Junior Varsity coach would not let us shoot threes, including the guards, and every time we would shoot one, whether it went in or not, we would have to run. This was much different from my senior year of high school playing on Varsity, as we were encouraged to push the pace as much as possible, drive the ball to the hoop, and look for a kick-out pass for an open three. I saw the style of play changing even more when watching the middle school kids play, as everybody was trying to shoot from distance and cross players up to be like Steph Curry. I think that kids see Stephen Curry and know that they can play like him if they work at it, unlike when I was playing basketball and watching LeBron James physically dominate his competition just because he was a freak athlete. Kids are very impressionable, and they want to play the way they see NBA players playing, creating the trickle-down effect of the game changing at every level.

“Five years ago, the average team ran an aggregate of 16.9 miles per game. This year, that’s up to 18.1 miles.”

As seen in the figure above comparing pace with offensive rebounding percentage over the last 10 years, teams want their players to get back and play transition defense rather than going for the offensive rebound. With the new rule this season of having the shot clock reset to 14 seconds on offensive rebounds instead of 24 seconds, the incentive of going for the offensive rebound is even smaller. Along with transition defense being a focus for teams in today’s NBA, defense as a whole has been improved from “Player Tracking” and advanced analytics. Teams can access data that tells them anything from how efficient an opposing player is from certain spots on the floor, to how efficient a player is depending on how close his defender is, to a player’s tendencies and habits. Let’s use JJ Redick as an example during his time with the Los Angeles Clippers:

JJ Redick has always been a threat from deep his entire career. Because of this, teams are always playing him close when he’s on the three point line. His tendency is to catch and shoot, but we can see that the Clippers are running plays to get him open. They’re setting multiple off-ball screens to get him some space from his defender, similar to what the Golden State Warriors do with Steph Curry. Here, teams can see his tendency to catch and shoot, and switch when they are hit with a screen. Even though JJ Redick may end up with a big man on him or another mismatch, all the defender needs to do is stay close, knowing he probably isn’t going to drive, and if he does, you can live with that as a team. This is the exact opposite of what you want to do on defense with a player like Russell Westbrook, who is always looking to drive to the hoop. Thanks to analytics, teams can now watch players’, as well as teams’, habits, find their strengths and weaknesses, and create a gameplan that gives their team the best chance to win.

Switch ability and versatility are now musts for NBA players. This is part of the decline of the traditional plodding big man who never leaves the paint. With teams shooting more threes than ever, opposing teams need to be focused on perimeter defense. Players today are always looking to get a clean look from distance, and the best way to do this is to have a bad defender on you. A guy like DeMarcus Cousins can’t guard a guy like Kyrie Irving on the perimeter, and luckily he doesn’t have to. Or does he? Teams are constantly sending their big men to set screens for their point guard (or best ball handler/player) so the defense is forced to either switch, or go over the screen to prevent the three. This usually leads to an easy bucket, whether it be the ball handler, the roller, or another player who becomes open when the defense is forced to help. A big can switch onto a guard and defend him straight up is a huge plus for any team. And it’s becoming almost a necessity. Players like Draymond Green, Anthony Davis, Al Horford, and Joel Embiid fit this mold, and they make it difficult for any opposing offense to run smoothly when they are on the court. When teams don’t have a player capable of switching onto smaller players, they are often forced to send out a small-ball lineup, which is becoming more and more common. Examples of these lineups would be the Golden State Warriors when they play Draymond (6’7″) at center, Los Angeles Lakers playing Brandon Ingram at the 4 (6’9″, 190 lbs) and LeBron James (6’8″) at center, or the Toronto Raptors playing OG Anonuby at the 4 (6’8″, 232 lbs) and Pascal Siakam at the 5 (6’9″, 230 lbs).

Pascal Siakam (#43) and OG Anunoby (#3)

The introduction of “Player Tracking” and the advanced statistics and analytics that come from that are definitely changing the game. There are more three-pointers being made and attempted than ever before, players are playing at an increasing pace, and teams are using as many defensive tactics as they can to limit efficient shots from opposing teams. I agree with Leigh Steinberg, who authored the article “CHANGING THE GAME: The Rise of Sports Analytics“, who wrote,”Look for the next analytical breakthrough to come in the areas of predicting how a player’s mental make-up will adjust to the rigors of professional sports and how the emotional aspect of the responsibility correlates to on-the-court performance. Teams need an analytic that predicts responsive behavior.” I think that the next step is analyzing and breaking down how off-the-court behaviors and actions affect on-the-court performances. I also believe that analytics will one day be able to measure a player’s heart and desire, although too much analytics being implemented in the NBA may make the game seem somewhat robotic and lack-luster. Either way, sports statistics and analytics will continue to grow, and the competition should continue to grow with it. The future of sports analytics has never been brighter.

1 thought on “How Advanced Statistics & Analytics has Changed the NBA”

  1. This is a really great overview, and you’ve done a nice job of bringing in more than just text. For revision, think about how to make this more your own. Right now it feels a bit generic — it’s a well done overview of how sports analytics have changed sports. I’d be curious to see more of your own ideas and analysis here. You’re experienced in this stuff now, so what can you add to this that brings it beyond being an overview?

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