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The statistics minded should like this... in fact, it is a good use of statistics.
Dissecting the demise
Breaking down two decades of decline in NBA scoring
Updated: Thursday October 28, 2004 11:39PM
Just 20 years ago, the NBA was in the midst of an offensive renaissance that had teams filling the nets like they were on an Alaskan fishing boat. It's difficult to remember now, but in 1984-85, the average NBA team scored 110.8 points per game. Every team in the league scored at least 104, while the Nuggets, Warriors and Kings all averaged more than 117. For a bit of perspective on how far things have sunk, that's a total the world champion Pistons didn't achieve once in the 2003-04 regular season.
In fact, last season, scoring plummeted to just 93.4 points a game for each team, a whopping 17.4 point decrease in two decades. The top teams were even more defensive-minded. In the Eastern Conference finals, for instance, Detroit and Indiana played a horrific six-game series in which neither team managed to eclipse 85 points.
The decline in offense is well known. But how did the league get here? While my SI.com colleagues are looking at some of the changes in techniques and attitudes that have allowed defense the upper hand, I'll be taking a more scientific approach by breaking down the numbers. The data should provide an explanation for the causes of the 17-point drop, as well as offer some insights into some solutions.
Let's start with the big picture. There are only two ways scoring can decrease: One is for teams to play slower, which reduces the number of possessions each team has over the course of a game; the other is for teams to get fewer points out of each possession.
Slow-motion hoops
We'll begin with playing slower, which teams have become a little too good at during the David Stern era. In '84-85, the average NBA team used 104.8 possessions in a 48-minute game. By last year, the league had come to a screeching halt, using just 92.0 possessions per game. NBA teams have nearly 13 chances a game fewer than they did two decades ago.
This is important because NBA teams score slightly more than one point for each time they have the ball. Those 13 chances could be expected to turn into about 13.3 points per game for each team. In other words, the biggest reason for the 17-point decrease in scoring isn't due to bad shooting, bad passing, changes in officiating or even the oft-cited increase in high-school aged kids entering the league. The main reason that offense has declined so much is because teams have stopped running. The change in pace alone accounts for 76.2 percent of the decline in scoring since '84-85. If the league reverted to the same pace it played at two decades ago, teams would average about 106.7 points a game.
Offensive offense
While a slower pace is the main culprit in lower scores, that doesn't let offenses off the hook. Regardless of the speed with which the game is played, teams have become less efficient on the offensive end. In fact, even after we adjust for the fewer number of possessions teams use, there's still a 4.1 points-per-game difference that results from teams getting less out of each trip down the floor. This is noteworthy since the increased use of the 3-pointer should have produced the opposite effect.
Let's break down that 4.1 points-per-game difference, because we'll see some interesting trends.
Offense breaks down into three categories -- shooting, avoiding turnovers, and offensive rebounding. And while the numbers are down, it isn't all doom and gloom for today's NBA. Offenses are actually quite a bit better than those of the past when it comes to holding onto the ball. Teams turned the ball over on 16.9 percent of their possessions two decades ago, but did so just 15.4 percent of the time in '03-04. Since teams score about 1.2 points on each possession without a turnover, the difference adds about 1.9 points per game to offenses. The cause of the turnover decline is no mystery -- with teams running less, they have fewer chances for open-court miscues.
But those gains are exactly offset by a decline in offensive rebounding. In '84-85, offenses grabbed the board on 32.9 percent of missed shots, but by '03-04 that had declined to 28.7 percent. That difference has cost offenses 2.0 points per game, and it probably results from 3-point shooters being spaced too far away from the basket to have a prayer of getting an offensive board.
Brick city
However, that still leaves the lion's share of the responsibility in decreased offensive efficiency at the doorstep of a common complaint: Declining shooting. Since '84-85, field-goal percentages have sunk roughly in proportion to Billy Squier's albums sales, from 49.1 percent to 43.9 percent last season. Sharp minds in the audience will quickly note that the 3-pointer is a much more prevalent part of modern offenses (teams try more than five times as many as they did two decades ago), so we should expect field-goal percentages to be lower in return for the greater payoff. Yet even allowing for the rise of the 3-pointer, shooting is still in the dumpster. Teams averaged 0.99 points for each field-goal attempt in 1984-85, but just 0.94 last season. That five-hundreths of a percentage point difference is enough to subtract 2.9 points a game from offenses.
That goes to underscore that the 3-pointer has, on balance, not had much of an effect. On the one hand, players shoot the long bomb much more accurately than twenty years ago -- improving from 28.1 percent to 34.7 percent -- which has added 1.9 points per game to scoring.
But there's a hidden cost to all of those 3s. Because they're bombing away instead of going to the rim, teams are getting to the line much less often. Teams took 0.33 free-throws per field-goal attempt back then, but only 0.30 last season, a change that cost teams about 1.7 points a game -- giving back nearly all of the difference from the increase in 3-point accuracy.
So.... What now?
Our study tells us two things about the state of scoring. First, pace is a much bigger factor than the decline in offensive efficiency. Second, the main cause of the dip in efficiency is the sharp drop in 2-point field-goal percentage.
One presumes that the league's goal is to increase scoring -- or at the very least to curb the decline before basketball turns into hockey. That suggests a couple of alternatives. First, rule changes that boost the pace should have a much greater effect than those that make it easier to operate in the halfcourt. The paradox is that rule changes that make it harder for teams to walk it up and score effectively could actually increase scoring. Unfortunately, this approach is rife with unintended consequences. For instance, recent changes, such as the eight-second rule (forcing teams to get the ball across mid-court in eight seconds instead of the previous 10) and the changes in the illegal defense rule, have made things harder for offenses while having no appreciable impact on teams' willingness to run and press. The league may be reluctant to go down this road again.
That leaves measures to improve a team's ability to score in the halfcourt. An obvious and long overdue one is being tried this preseason -- clamping down on forearm contact with dribblers and the gratuitous hand-checking that had become a staple of top defenses in recent seasons.
Beyond that, some of the other things the league could do have already been tried and proven hugely unpopular. For instance, nearly everyone considers the 3-to-make-2 foul shot a joke, and an attempt at moving in the 3-point line in 1994-95 turned the league into the Athens Olympics. One hopes that the officials' clampdown on contact this preseason isn't one of those short-lived officiating trends that veteran refs forget by Christmas. Otherwise the league doesn't have a lot of options.
In that case, commissioner Stern and his crew need to think long and hard about how to rescue offense. Most of the measures they can implement to increase pace make it harder to score in the halfcourt, while most of the measures that could make halfcourt scoring easier are even more unpopular with fans than the low-scoring games.
The one remaining hope may be that the players themselves become better shooters. Based on the brickfest in Athens, there's a better chance of Billy Squier making a comeback.
Dissecting the demise
Breaking down two decades of decline in NBA scoring
Updated: Thursday October 28, 2004 11:39PM
Just 20 years ago, the NBA was in the midst of an offensive renaissance that had teams filling the nets like they were on an Alaskan fishing boat. It's difficult to remember now, but in 1984-85, the average NBA team scored 110.8 points per game. Every team in the league scored at least 104, while the Nuggets, Warriors and Kings all averaged more than 117. For a bit of perspective on how far things have sunk, that's a total the world champion Pistons didn't achieve once in the 2003-04 regular season.
In fact, last season, scoring plummeted to just 93.4 points a game for each team, a whopping 17.4 point decrease in two decades. The top teams were even more defensive-minded. In the Eastern Conference finals, for instance, Detroit and Indiana played a horrific six-game series in which neither team managed to eclipse 85 points.
The decline in offense is well known. But how did the league get here? While my SI.com colleagues are looking at some of the changes in techniques and attitudes that have allowed defense the upper hand, I'll be taking a more scientific approach by breaking down the numbers. The data should provide an explanation for the causes of the 17-point drop, as well as offer some insights into some solutions.
Let's start with the big picture. There are only two ways scoring can decrease: One is for teams to play slower, which reduces the number of possessions each team has over the course of a game; the other is for teams to get fewer points out of each possession.
Slow-motion hoops
We'll begin with playing slower, which teams have become a little too good at during the David Stern era. In '84-85, the average NBA team used 104.8 possessions in a 48-minute game. By last year, the league had come to a screeching halt, using just 92.0 possessions per game. NBA teams have nearly 13 chances a game fewer than they did two decades ago.
This is important because NBA teams score slightly more than one point for each time they have the ball. Those 13 chances could be expected to turn into about 13.3 points per game for each team. In other words, the biggest reason for the 17-point decrease in scoring isn't due to bad shooting, bad passing, changes in officiating or even the oft-cited increase in high-school aged kids entering the league. The main reason that offense has declined so much is because teams have stopped running. The change in pace alone accounts for 76.2 percent of the decline in scoring since '84-85. If the league reverted to the same pace it played at two decades ago, teams would average about 106.7 points a game.
Offensive offense
While a slower pace is the main culprit in lower scores, that doesn't let offenses off the hook. Regardless of the speed with which the game is played, teams have become less efficient on the offensive end. In fact, even after we adjust for the fewer number of possessions teams use, there's still a 4.1 points-per-game difference that results from teams getting less out of each trip down the floor. This is noteworthy since the increased use of the 3-pointer should have produced the opposite effect.
Let's break down that 4.1 points-per-game difference, because we'll see some interesting trends.
Offense breaks down into three categories -- shooting, avoiding turnovers, and offensive rebounding. And while the numbers are down, it isn't all doom and gloom for today's NBA. Offenses are actually quite a bit better than those of the past when it comes to holding onto the ball. Teams turned the ball over on 16.9 percent of their possessions two decades ago, but did so just 15.4 percent of the time in '03-04. Since teams score about 1.2 points on each possession without a turnover, the difference adds about 1.9 points per game to offenses. The cause of the turnover decline is no mystery -- with teams running less, they have fewer chances for open-court miscues.
But those gains are exactly offset by a decline in offensive rebounding. In '84-85, offenses grabbed the board on 32.9 percent of missed shots, but by '03-04 that had declined to 28.7 percent. That difference has cost offenses 2.0 points per game, and it probably results from 3-point shooters being spaced too far away from the basket to have a prayer of getting an offensive board.
Brick city
However, that still leaves the lion's share of the responsibility in decreased offensive efficiency at the doorstep of a common complaint: Declining shooting. Since '84-85, field-goal percentages have sunk roughly in proportion to Billy Squier's albums sales, from 49.1 percent to 43.9 percent last season. Sharp minds in the audience will quickly note that the 3-pointer is a much more prevalent part of modern offenses (teams try more than five times as many as they did two decades ago), so we should expect field-goal percentages to be lower in return for the greater payoff. Yet even allowing for the rise of the 3-pointer, shooting is still in the dumpster. Teams averaged 0.99 points for each field-goal attempt in 1984-85, but just 0.94 last season. That five-hundreths of a percentage point difference is enough to subtract 2.9 points a game from offenses.
That goes to underscore that the 3-pointer has, on balance, not had much of an effect. On the one hand, players shoot the long bomb much more accurately than twenty years ago -- improving from 28.1 percent to 34.7 percent -- which has added 1.9 points per game to scoring.
But there's a hidden cost to all of those 3s. Because they're bombing away instead of going to the rim, teams are getting to the line much less often. Teams took 0.33 free-throws per field-goal attempt back then, but only 0.30 last season, a change that cost teams about 1.7 points a game -- giving back nearly all of the difference from the increase in 3-point accuracy.
So.... What now?
Our study tells us two things about the state of scoring. First, pace is a much bigger factor than the decline in offensive efficiency. Second, the main cause of the dip in efficiency is the sharp drop in 2-point field-goal percentage.
One presumes that the league's goal is to increase scoring -- or at the very least to curb the decline before basketball turns into hockey. That suggests a couple of alternatives. First, rule changes that boost the pace should have a much greater effect than those that make it easier to operate in the halfcourt. The paradox is that rule changes that make it harder for teams to walk it up and score effectively could actually increase scoring. Unfortunately, this approach is rife with unintended consequences. For instance, recent changes, such as the eight-second rule (forcing teams to get the ball across mid-court in eight seconds instead of the previous 10) and the changes in the illegal defense rule, have made things harder for offenses while having no appreciable impact on teams' willingness to run and press. The league may be reluctant to go down this road again.
That leaves measures to improve a team's ability to score in the halfcourt. An obvious and long overdue one is being tried this preseason -- clamping down on forearm contact with dribblers and the gratuitous hand-checking that had become a staple of top defenses in recent seasons.
Beyond that, some of the other things the league could do have already been tried and proven hugely unpopular. For instance, nearly everyone considers the 3-to-make-2 foul shot a joke, and an attempt at moving in the 3-point line in 1994-95 turned the league into the Athens Olympics. One hopes that the officials' clampdown on contact this preseason isn't one of those short-lived officiating trends that veteran refs forget by Christmas. Otherwise the league doesn't have a lot of options.
In that case, commissioner Stern and his crew need to think long and hard about how to rescue offense. Most of the measures they can implement to increase pace make it harder to score in the halfcourt, while most of the measures that could make halfcourt scoring easier are even more unpopular with fans than the low-scoring games.
The one remaining hope may be that the players themselves become better shooters. Based on the brickfest in Athens, there's a better chance of Billy Squier making a comeback.
