Shaquille O’Neal56.325.435.0 Nobody combined offense and defense like Tim Duncan 8Larry Bird41,329120.353.674.2 Wilt Chamberlain35.849.041.4 18Pau Gasol41,57281.438.552.2 4David Robinson38,492100.680.389.3 Includes all NBA regular seasons and playoffs from 1973-74 to the present.Source: Basketball-Reference.com 14Magic Johnson40,783149.134.656.2 11Jason Kidd56,19994.855.470.0 20Patrick Ewing45,80141.265.350.5 7Kareem Abdul-Jabbar50,840144.453.578.0 Kevin Garnett50.033.039.8 10Scottie Pippen49,17487.462.372.7 Hakeem Olajuwon30.638.534.1 The post-Jordan NBA era unofficially ended Monday, when San Antonio Spurs legend Tim Duncan announced his retirement after 19 seasons as a pro. Duncan was at the forefront of the league for the past two decades, winning five championships and a pair of MVPs as the best player of the generation that entered the league as MJ was on his way out. But for whatever reason — be it playing in small-market San Antonio, his relatively low-key public persona or all the things that go into a nickname like the Big Fundamental — Duncan’s greatness remains undersold in many quarters. So here are a couple of ways in which he made a case for being the best player in modern NBA history.All-around greatnessDuncan never scored more than 25 points per game after age 25, and he didn’t crack 20 PPG after turning 30. His low-post game, premised around that classic bank shot, was solid but rarely feared, particularly later in his career. But Duncan augmented his point totals with good efficiency, great rebounding and a nice passing touch for a big man that allowed him to anchor the Spurs’ offense even when his days as a big-time scorer were in the past.And on defense, Duncan was uniformly incredible throughout his career. He was named to 15 All-Defensive teams — the last of which came at age 38 — and led the league in defensive Win Shares five times, to go with nine other top-five finishes. In terms of suppressing offensive efficiency (relative to league average), Duncan’s Spurs were the NBA’s best defensive dynasty since Bill Russell’s Celtics. And even in the twilight of his career, Duncan consistently ranked among the league’s top five defensive players according to the plus/minus metrics. He’s undeniably on the shortlist of the best defenders in basketball history.Put it all together, and it’s hard to find a modern player with a better combination of offensive and defensive résumés than Duncan. To measure this, I used a couple of statistics from Basketball-Reference.com: value over replacement player (VORP) and Win Shares, both of which strive to capture a player’s total on-court influence over his team’s success.1Since VORP only goes back to 1973-74, that’s the earliest season included in my sample. I converted both metrics to a figure representing wins above replacement (WAR), and broke down each into its offensive and defensive components, zeroing out seasons where a player dipped into negative-value territory. Then I summed up offensive and defensive WAR for a player’s entire career — including the playoffs, where Duncan built a good amount of his legend — and took the harmonic mean (which favors balance between the two instead of a lopsided total in one category) of a player’s offensive and defensive tallies.By that standard, Duncan has no peers among modern NBA players: 13Charles Barkley44,179154.941.064.9 Moses Malone40.933.136.6 15Clyde Drexler43,109118.235.654.7 2Kevin Garnett55,701107.387.296.2 Kareem Abdul-Jabbar61.582.670.5 Paul Pierce36.337.436.8 19Horace Grant44,79368.341.351.5 6LeBron James46,861196.252.582.8 WINS ABOVE REPLACEMENT 3Karl Malone62,759162.567.595.4 Great both young and oldDuncan also performed those acts of all-around greatness for just about two decades straight, playing like a Hall of Famer as both a young player and an old one. Back in 2014, my colleague Nate Silver was curious about how rare that combination was for a player:I wondered which other players in the NBA, and in the other major team sports, have had so much impact over their full professional lives. In other words, which of them were both very effective as young players and as old players?For an answer, Nate looked at each player’s Win Shares before age 25 and after age 32, taking the harmonic mean (yes, that again) of the two numbers to find players who matched Duncan’s career path. There weren’t many.Since Duncan has only added to his post-32 totals since then, let’s re-run the same exercise, updated through the end of Duncan’s career: NBA WIN SHARES PLAYERTHROUGH AGE 24AGE 33 ONWARDHARMONIC MEAN Tim Duncan47.855.051.1 1Tim Duncan56,738108.1110.3109.2 Michael Jordan53.643.648.1 12Michael Jordan48,485206.541.669.2 PLAYERMINUTES PLAYEDOFFENSEDEFENSEHARMONIC MEAN 9Shaquille O’Neal50,016133.850.273.0 17Robert Parish51,88170.941.452.3 5Hakeem Olajuwon49,97179.593.385.9 The NBA’s best full life-cycle players Dirk Nowitzki53.037.543.9 Sorted by harmonic mean of NBA Win Shares through age 24 and from age 33 onward.Source: Basketball-Reference.com 16Shawn Marion43,93463.047.053.8 In the end, Duncan still trails Kareem Abdul-Jabbar — it’s really tough to beat that guy in longevity-based measures — but he did pass Michael Jordan for No. 2 all-time in Nate’s metric, another feather in Duncan’s cap as one of the best and truly unique players in NBA history.Better than the raw numbers?And as great as Duncan looks according to the numbers above, both studies were conducted using derivatives of the basic box-score stats. Those can be fine for estimating a player’s value in a broad sense, but they have a tendency to misfire in some areas — such as defense, or even the more subtle aspects of offense like screening or space-creation — where Duncan happened to excel.Perhaps that’s why, when Real Plus-Minus creator Jeremias Engelmann released a bank of adjusted plus/minus data encompassing the 2001-2014 seasons, Duncan ranked as the third-best player of that era, trailing only Kevin Garnett and LeBron James. That’s slightly higher than Duncan placed according to Player Efficiency Rating (he was fifth), Win Shares per 48 minutes (also fifth) or even Box Plus/Minus (sixth), which is designed to emulate plus/minus ratings derived from more granular data.In other words, Duncan’s contributions might be somewhat underrated when we line up his stats against those of other greats from history. The NBA won’t be the same without him in it next season.