Assignment 7 - Basketball Scoring Analysis

Author

Ethan Leamer

Introduction

I wanted to take a deep dive into how scoring in the NBA has changed since the introduction of the three point line. I want to investigate how the rise of the three pointer has changed the way many players play the game. I intend to answer this question by looking at how player’s habits have changed when it comes to what kinds of shots they are taking, and how often they are making these shots.

I scraped data that includes every player who played in the season and their stats from the 1981 season (when the three point line was introduced) to the 2025 regular season. I will collect this data by scraping tables of the player data from every year on the site basketball-reference.com.

Analysis

This graph clearly shows a slight upward trend that has a pretty constant slope between 1981 and 2014. Then there is a dramatic increase in the number of 3’s that are being taken at about 2014. In a matter of just 10 years that average number of three pointers taken by a player per game jumped from 1.6 to 2.6, the last increase of this size took about 25 years to happen. This is mainly because of players like Steph Curry, who mainly relied on 3’s for their offense, showed how effective it could be. I would also like to point out the spike from 1995 to 1997, this is due to the NBA moving the 3-point line closer in 1995 and the reverting it to its original position in 1998.

We can see here that there are many more players than ever scoring at least 20 points per game, in fact the number is about double any number from before the 2015 season. This shows that players are scoring at a much higher and more efficient rate. We can see that the increase in amount of high scoring players directly correlates to the increase in 3-pointers attempted per game. This shows that NBA coaches and players have found that shooting 3’s is for the most part, the best way to score in basketball.

This graph shows that not only have players been shooting more threes they are also making them at a rate never seen before. This can be attributed to the fact that since the revelation of how important the 3-point shot is, players have been practicing these types of shots more than ever and are therefore more likely to make them in a game. I would also like to again point out the discrepancy in the graph from 1995-1997 that is the same as in the graph shown before.

The graph shows that with players taking more 3-pointers they are less likely to be taking longer 2-point shots, which are almost as hard as 3-pointers but only worth 2/3 the points. So, players are either taking 3-pointers, or they are taking 2’s that are much closer to the basket. These 2’s that are closer to the basket are much easier shots and consequently being made at a much higher percentage then the mid-range shots that many players were shooting in the 90’s and early 2000’s.

The most often reason that a player is shooting free throws is because they drove to the basket and got fouled attempting a layup. This graph shows how the league moving towards shooting more three pointers has lowered the amount of players that are driving to the basket and drawing fouls.

Conclusion

The three point revolution has changed basketball dramatically in just about every facet of the offensive game. Firstly, due to the influence of players like Steph Curry and James Harden in the 2014-2016 season players began to take an exponentially increase number of 3-pointers, and because of this increase in 3’s taken the league started to see many more players scoring at very high levels. Next, we saw that as a whole league both 3-point percentage and 2-point percentage were increasing, due to both increased focus on 3’s in practice and better shot selection. Finally, the last graph illustrated that the number of free throws taken per game is at an all time low, due to more play being on the perimeter of the court.

--- title: "Assignment 7 - Basketball Scoring Analysis" # Name of your HTML output author: "Ethan Leamer" # Author name toc: true # Generates an automatic table of contents. format: # Options related to formatting. html: # Options related to HTML output. code-tools: TRUE # Allow the code tools option showing in the output. embed-resources: TRUE # Embeds all components into a single HTML file. execute: # Options related to the execution of code chunks. warning: FALSE # FALSE: Code chunk sarnings are hidden by default. message: FALSE # FALSE: Code chunk messages are hidden by default. echo: TRUE # TRUE: Show all code in the output. --- ### Introduction I wanted to take a deep dive into how scoring in the NBA has changed since the introduction of the three point line. I want to investigate how the rise of the three pointer has changed the way many players play the game. I intend to answer this question by looking at how player's habits have changed when it comes to what kinds of shots they are taking, and how often they are making these shots. I scraped data that includes every player who played in the season and their stats from the 1981 season (when the three point line was introduced) to the 2025 regular season. I will collect this data by scraping tables of the player data from every year on the site basketball-reference.com. ```{r} #| echo: FALSE # Hide the code in this chunk in the output library(tidyverse) # For all the tidy things! library(lubridate) # Convenient transforming of date values. library(knitr) nba_data <- read_csv("https://myxavier-my.sharepoint.com/:x:/g/personal/leamere_xavier_edu/EWg2S_Nv6AtAosGiGXzD90oBzn83C2bzeCF9tDT4TLTIUw?download=1") ``` ### Analysis ```{r} #| echo: FALSE nba_data %>% group_by(season) %>% summarise(avg_3PA = mean(X3PA, na.rm = TRUE)) %>% arrange(season) %>% ggplot(aes(x = season, y = avg_3PA)) + geom_line(color = "blue", size = 1.2) + geom_point(color = "darkred", size = 2) + labs(title = "Average 3-Point Attempts per Game by Season", x = "Season", y = "Average 3PA per Game") + theme_minimal() ``` This graph clearly shows a slight upward trend that has a pretty constant slope between 1981 and 2014. Then there is a dramatic increase in the number of 3's that are being taken at about 2014. In a matter of just 10 years that average number of three pointers taken by a player per game jumped from 1.6 to 2.6, the last increase of this size took about 25 years to happen. This is mainly because of players like Steph Curry, who mainly relied on 3's for their offense, showed how effective it could be. I would also like to point out the spike from 1995 to 1997, this is due to the NBA moving the 3-point line closer in 1995 and the reverting it to its original position in 1998. ```{r} #| echo: FALSE players_over_20ppg <- nba_data %>% filter(PTS > 20) %>% group_by(season) %>% summarise(count = n()) %>% ungroup() ggplot(players_over_20ppg, aes(x = season, y = count)) + geom_line(color = "blue") + geom_point(color = "blue") + labs(title = "Number of NBA Players Scoring > 20 PPG by Season", x = "Season", y = "Number of Players") + theme_minimal() + scale_x_continuous(breaks = seq(min(players_over_20ppg$season), max(players_over_20ppg$season), by = 5)) ``` We can see here that there are many more players than ever scoring at least 20 points per game, in fact the number is about double any number from before the 2015 season. This shows that players are scoring at a much higher and more efficient rate. We can see that the increase in amount of high scoring players directly correlates to the increase in 3-pointers attempted per game. This shows that NBA coaches and players have found that shooting 3's is for the most part, the best way to score in basketball. ```{r} #| echo: FALSE avg_3pt_percentage <- nba_data %>% filter(!is.na(X3P.)) %>% group_by(season) %>% summarise(avg_3pt = mean(X3P., na.rm = TRUE)) %>% ungroup() ggplot(avg_3pt_percentage, aes(x = season, y = avg_3pt)) + geom_line(color = "red") + geom_point(color = "red") + labs(title = "Average 3-Point Percentage by Season", x = "Season", y = "Average 3-Point Percentage") + theme_minimal() + scale_x_continuous(breaks = seq(min(avg_3pt_percentage$season), max(avg_3pt_percentage$season), by = 5)) + scale_y_continuous(labels = scales::percent_format(scale = 100)) ``` This graph shows that not only have players been shooting more threes they are also making them at a rate never seen before. This can be attributed to the fact that since the revelation of how important the 3-point shot is, players have been practicing these types of shots more than ever and are therefore more likely to make them in a game. I would also like to again point out the discrepancy in the graph from 1995-1997 that is the same as in the graph shown before. ```{r} #| echo: FALSE avg_2pt_percentage <- nba_data %>% filter(!is.na(X2P.)) %>% group_by(season) %>% summarise(avg_2pt = mean(X2P., na.rm = TRUE)) %>% ungroup() ggplot(avg_2pt_percentage, aes(x = season, y = avg_2pt)) + geom_line(color = "green") + geom_point(color = "green") + labs(title = "Average 2-Point Percentage by Season", x = "Season", y = "Average 2-Point Percentage") + theme_minimal() + scale_x_continuous(breaks = seq(min(avg_2pt_percentage$season), max(avg_2pt_percentage$season), by = 5)) + scale_y_continuous(labels = scales::percent_format(scale = 100)) ``` The graph shows that with players taking more 3-pointers they are less likely to be taking longer 2-point shots, which are almost as hard as 3-pointers but only worth 2/3 the points. So, players are either taking 3-pointers, or they are taking 2's that are much closer to the basket. These 2's that are closer to the basket are much easier shots and consequently being made at a much higher percentage then the mid-range shots that many players were shooting in the 90's and early 2000's. ```{r} #| echo: FALSE avg_fta <- nba_data %>% filter(!is.na(FTA)) %>% group_by(season) %>% summarise(avg_fta = mean(FTA, na.rm = TRUE)) %>% ungroup() ggplot(avg_fta, aes(x = season, y = avg_fta)) + geom_line(color = "purple") + geom_point(color = "purple") + labs(title = "Average Free Throw Attempts per Game by Season", x = "Season", y = "Average Free Throw Attempts") + theme_minimal() + scale_x_continuous(breaks = seq(min(avg_fta$season), max(avg_fta$season), by = 5)) ``` The most often reason that a player is shooting free throws is because they drove to the basket and got fouled attempting a layup. This graph shows how the league moving towards shooting more three pointers has lowered the amount of players that are driving to the basket and drawing fouls. ### Conclusion The three point revolution has changed basketball dramatically in just about every facet of the offensive game. Firstly, due to the influence of players like Steph Curry and James Harden in the 2014-2016 season players began to take an exponentially increase number of 3-pointers, and because of this increase in 3's taken the league started to see many more players scoring at very high levels. Next, we saw that as a whole league both 3-point percentage and 2-point percentage were increasing, due to both increased focus on 3's in practice and better shot selection. Finally, the last graph illustrated that the number of free throws taken per game is at an all time low, due to more play being on the perimeter of the court.