NFL Quarterback Analysis

Author

Marc Petrasek

Introduction

This analysis focuses on examining quarterback performance data from the NFL over multiple years. The dataset contains key passing statistics, such as completions, attempts, yards, touchdowns, interceptions, and various efficiency metrics, along with the player’s team, position, and other relevant performance details. The data was scraped from Pro Football Reference and includes records from 2021 to 2024, providing a snapshot of how NFL quarterbacks performed during these seasons.

The primary question of interest is: How do quarterback performance metrics (e.g., completions, passing yards, touchdowns, and interceptions) vary across multiple seasons, and what patterns can be identified regarding age, team, and awards? Specifically, I will aim to explore whether performance trends are consistent across years and how individual player statistics might relate to their team and position.

Data Source & Approach

To answer my research question, I will collect quarterback passing statistics for multiple years from Pro Football Reference using a web scraping approach. The data will be cleaned and structured by ensuring unique column names and adding a Year column to track the statistics across different seasons. I will then aggregate the data for multiple years into a single dataset and perform analysis on the trends, performance metrics, and key insights over time. Visualizations, such as line charts and bar graphs, will be used to explore how statistics like passing yards, touchdowns, and completion percentage have evolved, helping to identify patterns and provide insights into the changing dynamics of the NFL quarterback passing game.

Analysis

This bar graph displays a relatively stable yet slightly declining trend in aggregate NFL quarterback passing yards from 2021 to 2024, with 2021 showing the highest total and 2024 the lowest. This subtle decline may reflect shifts in offensive strategies, such as an increased emphasis on the running game or defensive improvements across the league. While the graph offers a useful macro-level view, it does not capture variations by individual quarterbacks, teams, or age groups—key components of the research question. This is what I will explore next.

This box plot provides insight into how quarterback passing performance, measured in total yards, varies by age bracket across multiple NFL seasons. Notably, quarterbacks in the 21–25 and 36–40 age ranges exhibit higher median passing yards compared to those in the 26–30 range, challenging the assumption that peak performance always occurs in the late 20s. The wide interquartile ranges in the older age brackets suggest that veteran quarterbacks often maintain high performance levels, possibly due to experience and starting consistency. Conversely, the 26–30 bracket shows a low median with many outliers, indicating a mix of both backups and standout performers. These patterns highlight that quarterback performance is not solely age-dependent and must be contextualized with team roles, game starts, and career stages when evaluating trends.

The bar chart shows that total quarterback touchdowns were highest in 2021, indicating a particularly strong year for passing offenses. In 2022, touchdowns dropped noticeably, suggesting a league-wide dip in QB scoring performance. The totals remained relatively stable in 2023 but rose again in 2024, though still below the 2021 peak.

The boxplot shows that the top 10 quarterbacks in 2021 had the highest median and widest range of passing yards, suggesting both high performance and variability. In contrast, 2022 through 2024 saw lower medians and tighter distributions, indicating more consistent but less prolific passing among top QBs. Outliers in 2022 reflect a few extreme performances, both high and low, despite an overall narrower interquartile range. The data suggests a gradual decline in top-tier QB passing yardage since 2021, highlighting a shift in offensive production or league dynamics.

The scatter plot illustrates a positive correlation between completions and interceptions among quarterbacks, meaning those who throw more often are generally more likely to be intercepted. The trend line reinforces this relationship, showing a steady increase in interceptions as completions rise. While many QBs cluster at lower completion and interception counts, there’s considerable spread among high-volume passers, indicating variability in interception rates. This pattern suggests that higher passing volume may increase risk exposure, though individual efficiency and decision-making also play a key role.

The line chart shows that average quarterback completion percentage increased steadily from 2021 to 2023, peaking at just under 62%, before dipping slightly in 2024. This trend aligns with the previous scatter plot insight, where more completions were associated with more interceptions—suggesting higher completion efficiency may come with increased risk. Despite the dip in 2024, completion percentages have remained consistently above 59%, indicating sustained passing accuracy league-wide. These trends, paired with the earlier decline in total passing yards and touchdowns, suggest that while quarterbacks may be getting more accurate, they might also be taking fewer deep or risky throws.

Conclusion

This analysis of NFL quarterback performance from 2021 to 2024 reveals evolving dynamics in the passing game. While average completion percentages have increased, total passing yards and touchdowns have generally declined since their peak in 2021. This indicates a possible shift toward safer, shorter throws that improve accuracy but reduce explosive yardage. Additionally, the positive correlation between completions and interceptions suggests that greater passing volume comes with increased turnover risk. Overall, quarterback play appears to be trending toward efficiency and consistency, though with trade-offs in big-play production and scoring output.

--- title: "NFL Quarterback Analysis" author: "Marc Petrasek" editor: visual 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 This analysis focuses on examining quarterback performance data from the NFL over multiple years. The dataset contains key passing statistics, such as completions, attempts, yards, touchdowns, interceptions, and various efficiency metrics, along with the player’s team, position, and other relevant performance details. The data was scraped from Pro Football Reference and includes records from 2021 to 2024, providing a snapshot of how NFL quarterbacks performed during these seasons. The primary question of interest is: How do quarterback performance metrics (e.g., completions, passing yards, touchdowns, and interceptions) vary across multiple seasons, and what patterns can be identified regarding age, team, and awards? Specifically, I will aim to explore whether performance trends are consistent across years and how individual player statistics might relate to their team and position. ## Data Source & Approach To answer my research question, I will collect quarterback passing statistics for multiple years from Pro Football Reference using a web scraping approach. The data will be cleaned and structured by ensuring unique column names and adding a `Year` column to track the statistics across different seasons. I will then aggregate the data for multiple years into a single dataset and perform analysis on the trends, performance metrics, and key insights over time. Visualizations, such as line charts and bar graphs, will be used to explore how statistics like passing yards, touchdowns, and completion percentage have evolved, helping to identify patterns and provide insights into the changing dynamics of the NFL quarterback passing game. ```{r} #| label: Setup #| include: FALSE library(tidyverse) library(ggplot2) library(httr) library(rvest) library(magrittr) library(dplyr) ``` ```{r} #| label: Load the Data #| include: FALSE qb_stats <- read_csv("https://myxavier-my.sharepoint.com/:x:/g/personal/petrasekm_xavier_edu/EXPbv9YkQOFNsS4fApDYup0BinZaRRsPJtN4WBFkQ9Lfjg?download=1") ``` ## Analysis ```{r} #| echo: FALSE total_passing_yards_per_year <- qb_stats %>% group_by(Year) %>% summarize(Total_Yards = sum(Yds, na.rm = TRUE)) ggplot(total_passing_yards_per_year, aes(x = factor(Year), y = Total_Yards, fill = factor(Year))) + geom_bar(stat = "identity", show.legend = FALSE) + scale_y_continuous(labels = scales::comma) + labs(title = "Total Passing Yards by Year", x = "Year", y = "Total Passing Yards") + theme_minimal() ``` This bar graph displays a relatively stable yet slightly declining trend in aggregate NFL quarterback passing yards from 2021 to 2024, with 2021 showing the highest total and 2024 the lowest. This subtle decline may reflect shifts in offensive strategies, such as an increased emphasis on the running game or defensive improvements across the league. While the graph offers a useful macro-level view, it does not capture variations by individual quarterbacks, teams, or age groups—key components of the research question. This is what I will explore next. ```{r} #| echo: FALSE qb_stats$AgeBracket <- ifelse(qb_stats$Age >= 21 & qb_stats$Age <= 25, "21-25", ifelse(qb_stats$Age >= 26 & qb_stats$Age <= 30, "26-30", ifelse(qb_stats$Age >= 31 & qb_stats$Age <= 35, "31-35", ifelse(qb_stats$Age >= 36 & qb_stats$Age <= 40, "36-40", NA)))) qb_stats_clean <- qb_stats %>% filter(!is.na(AgeBracket) & !is.na(Yds)) ggplot(qb_stats_clean, aes(x = AgeBracket, y = Yds, fill = AgeBracket)) + geom_boxplot() + labs( title = "Quarterback Passing Yards by Age Bracket", x = "Age Bracket", y = "Total Passing Yards" ) + theme_minimal() ``` This box plot provides insight into how quarterback passing performance, measured in total yards, varies by age bracket across multiple NFL seasons. Notably, quarterbacks in the 21–25 and 36–40 age ranges exhibit higher median passing yards compared to those in the 26–30 range, challenging the assumption that peak performance always occurs in the late 20s. The wide interquartile ranges in the older age brackets suggest that veteran quarterbacks often maintain high performance levels, possibly due to experience and starting consistency. Conversely, the 26–30 bracket shows a low median with many outliers, indicating a mix of both backups and standout performers. These patterns highlight that quarterback performance is not solely age-dependent and must be contextualized with team roles, game starts, and career stages when evaluating trends. ```{r} #| echo: false qb_stats %>% group_by(Year) %>% summarise(total_td = sum(TD, na.rm = TRUE)) %>% ggplot(aes(x = Year, y = total_td)) + geom_col(fill = "tomato") + labs(title = "Total QB Touchdowns by Year", x = "Year", y = "Total TDs") + theme_minimal() ``` The bar chart shows that total quarterback touchdowns were highest in 2021, indicating a particularly strong year for passing offenses. In 2022, touchdowns dropped noticeably, suggesting a league-wide dip in QB scoring performance. The totals remained relatively stable in 2023 but rose again in 2024, though still below the 2021 peak. ```{r} #| echo: false qb_stats %>% group_by(Year) %>% arrange(desc(Yds), .by_group = TRUE) %>% slice_head(n = 10) %>% ggplot(aes(x = as.factor(Year), y = Yds)) + geom_boxplot(fill = "skyblue", color = "darkblue", outlier.color = "red") + labs(title = "Distribution of Passing Yards for Top 10 QBs Each Year", x = "Year", y = "Passing Yards") + theme_minimal() ``` The boxplot shows that the top 10 quarterbacks in 2021 had the highest median and widest range of passing yards, suggesting both high performance and variability. In contrast, 2022 through 2024 saw lower medians and tighter distributions, indicating more consistent but less prolific passing among top QBs. Outliers in 2022 reflect a few extreme performances, both high and low, despite an overall narrower interquartile range. The data suggests a gradual decline in top-tier QB passing yardage since 2021, highlighting a shift in offensive production or league dynamics. ```{r} #| echo: false qb_stats %>% filter(!is.na(Int), !is.na(Cmp)) %>% ggplot(aes(x = Cmp, y = Int,)) + geom_point(alpha = 0.7) + geom_smooth(method = "lm", se = FALSE, color = "black", linetype = "dashed") + labs(title = "Completions vs. Interceptions by QB (Colored by Year)", x = "Completions", y = "Interceptions", color = "Year") + theme_minimal() ``` The scatter plot illustrates a positive correlation between completions and interceptions among quarterbacks, meaning those who throw more often are generally more likely to be intercepted. The trend line reinforces this relationship, showing a steady increase in interceptions as completions rise. While many QBs cluster at lower completion and interception counts, there's considerable spread among high-volume passers, indicating variability in interception rates. This pattern suggests that higher passing volume may increase risk exposure, though individual efficiency and decision-making also play a key role. ```{r} #| echo: false qb_stats %>% filter(!is.na(Cmp.)) %>% group_by(Year) %>% summarize(avg_cmp_pct = mean(Cmp., na.rm = TRUE)) %>% ggplot(aes(x = Year, y = avg_cmp_pct)) + geom_line(color = "steelblue", size = 1.2) + geom_point(color = "steelblue", size = 2) + labs(title = "Average Completion Percentage by Year", x = "Year", y = "Average Completion %") + scale_y_continuous(labels = scales::percent_format(scale = 1)) + theme_minimal() ``` The line chart shows that average quarterback completion percentage increased steadily from 2021 to 2023, peaking at just under 62%, before dipping slightly in 2024. This trend aligns with the previous scatter plot insight, where more completions were associated with more interceptions—suggesting higher completion efficiency may come with increased risk. Despite the dip in 2024, completion percentages have remained consistently above 59%, indicating sustained passing accuracy league-wide. These trends, paired with the earlier decline in total passing yards and touchdowns, suggest that while quarterbacks may be getting more accurate, they might also be taking fewer deep or risky throws. ## Conclusion This analysis of NFL quarterback performance from 2021 to 2024 reveals evolving dynamics in the passing game. While average completion percentages have increased, total passing yards and touchdowns have generally declined since their peak in 2021. This indicates a possible shift toward safer, shorter throws that improve accuracy but reduce explosive yardage. Additionally, the positive correlation between completions and interceptions suggests that greater passing volume comes with increased turnover risk. Overall, quarterback play appears to be trending toward efficiency and consistency, though with trade-offs in big-play production and scoring output.