Section 1: Introduction

In this project, I will be examining several questions about NBA players statistics. The data I will be using is based on seasons staring in 1996, up through the 2022 season. The questions I plan to answer are: 1. What is the average career length of NBA players during this period? Are there differences in career lengths between players in different positions? 2. How does the average performance (points, assists, rebounds) change with players’ age? Are there players who continued to excel at an older age? 3. What is the distribution of player net rating across seasons? Can you identify any outliers who consistently maintain a high net rating? 4. How has the average salary of NBA players changed over the years? Are there players who are highly paid but have relatively low performance? 5. How has the representation of international players in the NBA evolved over time? Are there any international players who significantly impacted the league?

Section 1.1: Data

A sample of the data I will be using to answer these questions is shown below.

##   X      player_name team_abbreviation age player_height player_weight
## 1 0 Randy Livingston               HOU  22        193.04      94.80073
## 2 1 Gaylon Nickerson               WAS  28        190.50      86.18248
## 3 2     George Lynch               VAN  26        203.20     103.41898
## 4 3   George McCloud               LAL  30        203.20     102.05820
## 5 4     George Zidek               DEN  23        213.36     119.74829
## 6 5   Gerald Wilkins               ORL  33        198.12     102.05820
##                 college country draft_year draft_round draft_number gp  pts reb
## 1       Louisiana State     USA       1996           2           42 64  3.9 1.5
## 2 Northwestern Oklahoma     USA       1994           2           34  4  3.8 1.3
## 3        North Carolina     USA       1993           1           12 41  8.3 6.4
## 4         Florida State     USA       1989           1            7 64 10.2 2.8
## 5                  UCLA     USA       1995           1           22 52  2.8 1.7
## 6 Tennessee-Chattanooga     USA       1985           2           47 80 10.6 2.2
##   ast net_rating oreb_pct dreb_pct usg_pct ts_pct ast_pct  season
## 1 2.4        0.3    0.042    0.071   0.169  0.487   0.248 1996-97
## 2 0.3        8.9    0.030    0.111   0.174  0.497   0.043 1996-97
## 3 1.9       -8.2    0.106    0.185   0.175  0.512   0.125 1996-97
## 4 1.7       -2.7    0.027    0.111   0.206  0.527   0.125 1996-97
## 5 0.3      -14.1    0.102    0.169   0.195  0.500   0.064 1996-97
## 6 2.2       -5.8    0.031    0.064   0.203  0.503   0.143 1996-97

Section 2: Career Longevity

Section 2.1: Average Career Length of NBA Players from 1996-2022

## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
## [1] 5.294786

Based on my data, it appears that the average career length for NBA players during this time period is 5.294786 years.

Section 2.2: Difference Between Career Lengths by Position

Unfortunately, this question is unanswerable given the data provided. Without a variable including the player’s position, I am unable to calculate the differences in career length by position.

Section 3: Age and Performance

Section 3.1: Change in Performance with Players Age

Based on this line line graph, it appears that performance in assists, points, and rebounds by age varies. Performance in points appears to have 2 peaks: at age 21, and at age 28. After age 21, points decrease until about age 23, where performance then begins to increase until it peaks again at age 28, and decreasing again thereafter. Performance in rebounds seems to be steady through age with no obvious peaks. There are, however, 3 points on the graph where performance to declines: age 21, age 38, and age 42. After ages 21 and 38, performance in rebounds increases, but after age 42, it does not appear to increase after the decline. Performance in assists seems to gradually increase through age, but has a sharp decline at age 40.

Section 3.2: Players who Excel at an Older Age

## # A tibble: 10 × 9
##    player_name      age season    pts   ast   reb pts_increase ast_increase
##    <chr>          <dbl> <chr>   <dbl> <dbl> <dbl> <lgl>        <lgl>       
##  1 LeBron James      37 2021-22  30.3   6.2   8.2 TRUE         FALSE       
##  2 Stephen Curry     35 2022-23  29.4   6.3   6.1 TRUE         FALSE       
##  3 LeBron James      38 2022-23  28.9   6.8   8.3 FALSE        TRUE        
##  4 Karl Malone       36 1999-00  25.5   3.7   9.5 TRUE         FALSE       
##  5 LeBron James      35 2019-20  25.3  10.2   7.8 FALSE        TRUE        
##  6 Karl Malone       35 1998-99  23.8   4.1   9.4 FALSE        TRUE        
##  7 Karl Malone       37 2000-01  23.2   4.5   8.3 FALSE        TRUE        
##  8 Michael Jordan    39 2001-02  22.9   5.2   5.7 FALSE        TRUE        
##  9 Karl Malone       38 2001-02  22.4   4.3   8.6 FALSE        FALSE       
## 10 Kobe Bryant       36 2014-15  22.3   5.6   5.7 TRUE         FALSE       
## # ℹ 1 more variable: reb_increase <lgl>

Here, the top 10 players who continue to excel at an older age (where age >= 35 years) are displayed in descending order by overall performance.

Section 4: Player Efficiency

Section 4.1: Distribution of Net Rating Across Seasons

This series of boxplots displays the distribution of net rating across the seasons. It appears that most seasons have similar distributions, and there are a handful of obvious outliers.

Section 4.2: Identifying Outlier with Consistently High Net Ratings

## # A tibble: 9 × 2
##   player_name              n
##   <chr>                <int>
## 1 Brian Cardinal           2
## 2 Devontae Cacok           2
## 3 Draymond Green           2
## 4 Jaylen Morris            2
## 5 Kendrick Perkins         2
## 6 Kostas Antetokounmpo     2
## 7 Naz Mitrou-Long          2
## 8 Shavlik Randolph         2
## 9 Stephen Curry            2

This table displays 9 players who were outliers in the data. These players had consistently high net ratings in 1 or more seasons. The “high” net rating threshold was defined by values above the 3rd quartile (75th percentile) plus 1.5 times the interquartile range (IQR).

Section 5: Contract Analysis

To answer this question, I will be using a data set from kaggle.com that is specific to NBA players’ salary fro 1990 to 2017. An sample of this data set is shown below.

##   Register.Value Player.Name        Salary Season.Start Season.End Team
## 1              1  A.C. Green $1,750,000.00         1990       1991  LAL
## 2            354  A.C. Green $1,750,000.00         1991       1992  LAL
## 3            727  A.C. Green $1,750,000.00         1992       1993  LAL
## 4           1103  A.C. Green $1,885,000.00         1993       1994  PHO
## 5           1497  A.C. Green $6,472,600.00         1994       1995  PHO
## 6           1832  A.C. Green $6,473,000.00         1995       1996  PHO
##       Full.Team.Name
## 1 Los Angeles Lakers
## 2 Los Angeles Lakers
## 3 Los Angeles Lakers
## 4       Phoenix Suns
## 5       Phoenix Suns
## 6       Phoenix Suns

Section 5.1: Changes in Average Salary Over the Years

Here, a line graph shows the change in average salary from 1990 to 2017. As displayed in the graph, the average salary has grown dramatically over the 27 year period. At the beginning of the data in 1990, the average salary was approximately 1 million USD. In 2017, the average salary was approximately 6.5 million USD.

Section 5.2: Relationship Between Salary and Net Rating

Players with High Salaries and Low Net Ratings (Averaged Across Seasons)
Player Name Average Net Rating Average Salary ($)
Adonal Foyle -9.140000 7718750
Al Harrington -10.275000 8158108
Al Horford -6.900000 16324929
Al Jefferson -9.366667 12354167
Al-Farouq Aminu -6.466667 7500000
Alan Henderson -10.400000 7682188
Alec Burks -8.050000 10071162
Allan Houston -6.300000 14447917
Allen Crabbe -15.000000 18916250
Allen Iverson -7.000000 15196875
Alonzo Mourning -5.000000 15754920
Amir Johnson -14.550000 10500000
Anderson Varejao -15.575000 8418192
Andray Blatche -7.616667 8471339
Andre Drummond -5.433333 22946128
Andre Miller -5.300000 8139208
Andre Roberson -18.400000 9259259
Andrea Bargnani -10.640000 10222500
Andrei Kirilenko -39.300000 13979725
Andres Nocioni -9.133333 7712500
Andrew Bogut -5.850000 12138996
Andrew Bynum -11.800000 14504000
Andrew Wiggins -7.600000 7574322
Andris Biedrins -7.175000 9000000
Anfernee Hardaway -5.950000 11714375
Antawn Jamison -8.633333 13106368
Anthony Davis -5.500000 17654329
Anthony Tolliver -6.000000 8000000
Antoine Walker -7.300000 10180514
Antonio Davis -8.900000 12462500
Antonio McDyess -9.766667 11250000
Arron Afflalo -7.350000 8479167
Austin Croshere -12.166667 7682500
Austin Rivers -6.800000 11412500
Avery Bradley -11.100000 8000000
Baron Davis -8.300000 12737609
Ben Gordon -9.340000 10800000
Ben Wallace -6.300000 12100000
Beno Udrih -6.760000 7148700
Bismack Biyombo -10.371429 17000000
Bobby Simmons -7.900000 9416533
Bogdan Bogdanovic -8.600000 9470614
Bojan Bogdanovic -8.000000 10500000
Bonzi Wells -8.000000 7566667
Boris Diaw -6.233333 7625000
Brad Miller -6.900000 9479167
Brandon Bass -10.050000 6900000
Brandon Jennings -13.100000 8000000
Brandon Knight -9.166667 12741667
Brandon Roy -6.100000 14899968
Brendan Haywood -12.733333 7262250
Brian Cardinal -9.325000 6750000
Brian Grant -6.233333 12057331
Brook Lopez -9.833333 17981624
Bryant Reeves -8.420000 10110844
Cameron Bairstow -11.800000 9922530
Carl Landry -11.100000 8500000
Carlos Boozer -10.550000 13015124
Carmelo Anthony -7.450000 19717561
Caron Butler -8.725000 8656238
Chandler Parsons -13.466667 18822564
Channing Frye -10.700000 7802734
Charlie Villanueva -11.650000 8060000
Chauncey Billups -7.933333 10680000
Chris Kaman -8.040000 10388333
Chris Webber -8.800000 12151501
Chris Wilcox -10.833333 6750000
Clifford Robinson -9.450000 7656042
Cody Zeller -9.300000 12584270
Cole Aldrich -11.250000 7471990
Corey Brewer -9.700000 7793122
Corey Maggette -8.475000 7756322
Cory Joseph -7.033333 7320000
Courtney Lee -7.100000 11494945
Cristiano Felicio -10.700000 7843500
Cuttino Mobley -8.400000 8455000
D.J. Augustin -13.533333 7250000
Dale Davis -10.100000 8548906
Damon Stoudamire -7.600000 12175000
Dan Gadzuric -7.375000 6998792
Danny Granger -8.900000 12000000
Danny Green -5.750000 10000000
Darius Miles -10.666667 7800000
Darko Milicic -12.083333 7260000
Darrell Arthur -8.750000 7767544
Darren Collison -18.400000 10000000
David Lee -6.500000 11405993
David West -13.550000 10234375
DeAndre Jordan -10.040000 15192440
DeMar DeRozan -6.600000 16556015
DeMarcus Cousins -6.633333 15862961
Dennis Rodman -7.100000 9000000
Dennis Schroder -11.450000 15500000
Derek Anderson -10.600000 8281125
Deron Williams -6.200000 16503708
Derrick Coleman -11.550000 7862950
Derrick Favors -8.966667 11954166
Derrick Rose -6.200000 16489042
Desmond Mason -13.533333 7685185
Devin Harris -8.200000 8600000
Dion Waiters -5.800000 11000000
Doug Christie -13.100000 7225000
Draymond Green -7.200000 15343478
Drew Gooden -7.983333 6919292
Dwight Howard -7.400000 19422499
Dwight Powell -6.400000 8689062
Dwyane Wade -6.200000 16389610
Ed Davis -8.933333 6833334
Eddy Curry -18.100000 9618508
Elton Brand -9.840000 13946146
Emeka Okafor -7.900000 12510650
Enes Kanter -9.066667 18037547
Eric Bledsoe -7.000000 13440218
Eric Gordon -6.525000 13948991
Eric Snow -10.000000 7007812
Erick Dampier -10.150000 9331714
Ersan Ilyasova -10.050000 8000000
Etan Thomas -13.575000 7107100
Evan Turner -9.200000 13401486
Garrett Temple -7.283333 8000000
Gerald Henderson -11.066667 9000000
Gerald Wallace -5.650000 10000000
Gilbert Arenas -6.000000 13986947
Glen Rice -26.000000 7538333
Glenn Robinson -7.350000 9258250
Goran Dragic -6.350000 11695075
Gordon Hayward -8.250000 18989152
Gorgui Dieng -10.040000 14112360
Grant Hill -5.500000 11841583
Greg Monroe -7.125000 17128059
Greg Oden -7.500000 6760524
Greg Ostertag -9.400000 7799997
Harrison Barnes -6.400000 22614377
Hassan Whiteside -76.500000 22946128
Hedo Turkoglu -20.400000 10151958
Horace Grant -7.100000 12328571
Ian Mahinmi -16.700000 16302898
Iman Shumpert -9.000000 9679026
Isaiah Thomas -7.600000 7075738
JaMychal Green -7.450000 8533333
JaVale McGee -8.814286 10666667
Jabari Parker -5.633333 6782392
Jalen Rose -6.900000 12676458
Jamaal Magloire -8.550000 8500000
Jamaal Tinsley -20.200000 6750000
Jamal Crawford -10.116667 9793679
Jameer Nelson -6.400000 8100000
James Johnson -9.933333 13954000
James Posey -6.400000 7372200
Jared Jeffries -5.300000 6883800
Jason Richardson -7.000000 11777777
Jason Terry -6.333333 9033062
Jason Williams -9.350000 7791667
Jayson Williams -7.250000 13075000
Jeff Green -8.680000 10652500
Jeff Teague -5.700000 10360000
Jeremy Lamb -10.000000 7000000
Jeremy Lin -7.100000 10058136
Jerome Williams -6.700000 7639400
Jerry Stackhouse -13.433333 7292187
Jerryd Bayless -11.400000 9212042
Joakim Noah -10.300000 13760833
Joe Johnson -52.650000 15412676
Joe Smith -9.900000 6807000
Joel Przybilla -14.840000 6857725
John Henson -11.500000 11970071
John Salmons -7.940000 8041500
John Wall -6.860000 14615925
Jon Leuer -15.650000 10744638
Jonathan Bender -12.775000 7175000
Jordan Clarkson -9.650000 12031250
Jordan Hill -9.000000 9000000
Jose Calderon -9.980000 7961370
Josh Childress -8.533333 7317500
Josh Howard -11.000000 9945000
Josh Smith -16.100000 11362643
Jrue Holiday -5.100000 13337334
Juwan Howard -9.228571 15053571
Kelvin Cato -6.750000 7992000
Kemba Walker -11.300000 12000000
Kendall Gill -6.833333 7000000
Kendrick Perkins -5.800000 7800531
Kenneth Faried -5.000000 12078652
Kenny Anderson -9.200000 7933750
Kenny Thomas -8.775000 8175000
Kent Bazemore -9.466667 16320226
Kenyon Martin -6.400000 14045454
Kerry Kittles -6.950000 8483889
Kevin Durant -10.600000 20100462
Kevin Love -7.220000 17898290
Kevin Martin -8.033333 10132088
Khris Middleton -8.200000 14766667
Kirk Hinrich -9.500000 9570000
Kobe Bryant -12.833333 19102166
Kosta Koufos -8.960000 7979833
Kris Humphries -7.671429 10666667
Kurt Thomas -5.400000 7956335
Kwame Brown -7.140000 7903125
Kyle Lowry -5.200000 16175926
Kyrie Irving -5.266667 14580854
Lamar Odom -7.450000 10452331
Lance Stephenson -7.250000 9000000
Langston Galloway -8.050000 6666667
Larry Hughes -10.700000 12438188
Larry Sanders -7.425000 11000000
Latrell Sprewell -16.700000 10688571
Leandro Barbosa -5.500000 7350000
Lorenzen Wright -7.000000 7425000
Lou Williams -7.466667 7000000
Luis Scola -7.150000 8183586
Luol Deng -13.350000 12606150
Malik Rose -8.125000 7374375
Marc Gasol -7.000000 17287398
Marcin Gortat -6.350000 9744523
Marcus Camby -7.625000 9147454
Marcus Thornton -9.266667 7787500
Mark Blount -8.850000 7717235
Markelle Fultz -5.900000 7026240
Markieff Morris -7.266667 7800000
Marko Jaric -7.350000 7362500
Marvin Williams -5.400000 8739844
Mason Plumlee -5.750000 14041096
Matt Geiger -42.000000 7277227
Matthew Dellavedova -7.150000 9607500
Maurice Harkless -8.033333 9575843
Maurice Taylor -10.300000 8450000
Mehmet Okur -11.966667 8940714
Metta World Peace -10.175000 7163604
Meyers Leonard -10.400000 9558990
Michael Finley -6.600000 11367625
Michael Kidd-Gilchrist -8.200000 13000000
Michael Redd -10.200000 15150000
Mike Bibby -7.600000 11569086
Mike Conley -8.200000 14809856
Mike Dunleavy -5.700000 9390496
Mike Miller -7.316667 8305716
Miles Plumlee -7.950000 12500000
Mirza Teletovic -8.100000 10500000
Mo Williams -6.700000 8543833
Monta Ellis -7.200000 10178750
Nazr Mohammed -8.071429 6883800
Nene -51.550000 11342857
Nick Collison -10.733333 13250000
Nick Van Exel -7.750000 10445061
Nikola Pekovic -12.333333 12000000
Nikola Vucevic -6.550000 11750000
O.J. Mayo -10.300000 8000000
Omer Asik -7.850000 9649858
Otis Thorpe -12.500000 7000000
P.J. Brown -9.300000 7920960
P.J. Tucker -5.500000 7590035
Patrick Ewing -18.400000 17931000
Patty Mills -13.266667 10714286
Pau Gasol -6.725000 15201813
Quentin Richardson -9.420000 8270850
Raef LaFrentz -10.266667 10354557
Rajon Rondo -9.033333 11250000
Rashard Lewis -12.950000 13116758
Rasho Nesterovic -10.400000 7840000
Reggie Jackson -8.800000 14985507
Richard Hamilton -5.966667 9544643
Richard Jefferson -9.533333 11099111
Ricky Davis -10.560000 6819000
Ricky Rubio -5.000000 13396667
Robert Covington -7.800000 16698103
Robin Lopez -7.066667 13335917
Rod Strickland -6.333333 10000000
Rodney Stuckey -7.400000 8000000
Ron Mercer -9.675000 6750000
Roy Hibbert -18.000000 14592383
Rudy Gay -8.050000 14555640
Russell Westbrook -5.700000 19316107
Ryan Anderson -9.700000 12052303
Samuel Dalembert -10.650000 9760751
Scottie Pippen -22.000000 15640272
Serge Ibaka -6.500000 13852346
Sergio Rodriguez -7.733333 8000000
Shane Battier -5.600000 7109350
Shareef Abdur-Rahim -8.066667 11813333
Shaun Livingston -9.400000 7692308
Shawn Bradley -5.900000 7560000
Solomon Hill -5.850000 11738876
Speedy Claxton -8.433333 6854546
Spencer Hawes -9.300000 8500000
Stephen Curry -15.300000 15736510
Stephen Jackson -5.100000 9658125
Stephon Marbury -8.166667 14131806
Steve Francis -5.200000 12393655
Steve Nash -8.900000 10621174
T.J. Ford -6.700000 8250000
Taj Gibson -12.500000 9750000
Tariq Abdul-Wahad -7.566667 6750000
Tayshaun Prince -6.150000 8294158
Terrence Ross -10.350000 10250000
Thaddeus Young -7.800000 10561180
Theo Ratliff -14.150000 10071614
Tim Thomas -6.200000 11272500
Timofey Mozgov -9.733333 15640000
Tobias Harris -6.966667 16400000
Tom Gugliotta -9.433333 9967200
Toni Kukoc -5.100000 8337678
Tony Snell -6.650000 9821429
Tracy McGrady -8.733333 15174472
Travis Outlaw -18.800000 7000000
Trevor Ariza -6.166667 7682412
Trevor Booker -7.550000 9187500
Tristan Thompson -9.040000 15330435
Troy Murphy -8.300000 9942857
Ty Lawson -6.200000 11191012
Tyler Zeller -8.000000 8000000
Tyreke Evans -6.700000 10737946
Tyson Chandler -9.580000 12181371
Udonis Haslem -14.571429 7100000
Victor Oladipo -5.700000 21000000
Vin Baker -19.200000 11251000
Vince Carter -7.200000 12591756
Vlade Divac -14.200000 10087000
Vladimir Radmanovic -8.666667 6883800
Wesley Matthews -7.200000 13101059
Wesley Person -8.000000 7350000
Wilson Chandler -6.066667 10118692
Yao Ming -14.300000 15397494
Zach Randolph -9.425000 14049310
Zydrunas Ilgauskas -7.900000 11053413

This table displays all of the players who have a low average net-rating but high average salary. For this table, an “high” salary was defined as a salary above the 3rd quartile (75% percentile) and “low” net-rating was defined as below the 1st quartile (25th percentile).

Section 6: International Impact

Section 6.1: Evolution of International Players in the NBA

This line graph displays the evolution of the number of international players in the NBA. Starting in 1996, the number of international players appears to be approximately 10. In the most recent year in my data (2022), there are over 125 international players in the NBA.

Section 6.2: International Players who Impacted the League

## # A tibble: 42 × 2
##    player_name           avg_net_rating
##    <chr>                          <dbl>
##  1 Angel Delgado                   7   
##  2 Arvydas Sabonis                 7.12
##  3 Boban Marjanovic                7.2 
##  4 Christian Koloko                9   
##  5 Edy Tavares                     6.05
##  6 Enes Freedom                    7.8 
##  7 Festus Ezeli                    6.3 
##  8 Gabriel Lundberg               18.3 
##  9 Gian Clavell                   14.8 
## 10 Giannis Antetokounmpo           5.13
## # ℹ 32 more rows

Here, the table displays players who significantly impacted the league. These 10 players had average net rating in the top 10% of all international players.