Wednesday, September 3, 2014

Melo & LeBron: Career 30 game moving averages

Carmelo Anthony is a unique player in the NBA in that he is granted superstar status and money despite only reaching the conference finals once in his 12 year career. His critics have questioned his effort on defense and the adverse effect of his individual offensive play on his team. All this begs the question: Is Carmelo Anthony really a superstar? Considering that a big part of being a superstar in the NBA is fan appeal and scoring--two criteria Carmelo certainly exceeds in--the answer is 'yes'. However I'm interested if he will at the minimum maintain his offensive output when he begins his first full season as a thirty year old. To get a better picture of his performance I collected data on each of his regular season games over the course of his entire career from  

I focused on three conventional statistics--points, field goal attempts (FGA) and plus/ minus. I wanted to see how he progressed in each statistics from his first regular season game to his most recent. I only included games where he played at least one minute which resulted in a population of 708 games. Simply plotting these three conventional statistics in chronological order from game 1 to game 708 would have created a visual mess as the variance between individual 'good' and 'bad' games would have had lines darting everywhere.

As a result, I took a technique common in stock charts to smooth the performance. I captured a moving 30 game average of  each statistic. This technique allows me to chart his performance over a sufficient amount of play, thus giving a better understanding of sustained performance as opposed to capturing anomalous high/ low output performances. To create the moving average, I did not include Carmelo's first 29 games of his career because those games are necessary (with the 30th game) to create the starting point for the 30 game moving average. As a result, the charts below actually capture 679 games (708 career games - Carmelo's first 29 games).

To give some idea as to how the chart progresses, the point for game 2 on the plot represents the 30 game average from his career game 2 through game 31. Point 3 represents the 30 game average from his career game 3 through game 32. All the way up to the final point, which represents the 30 game average for his career game 679 through game 708. (Obviously, all points are connected with a line.)

The top chart shows Carmelo's 30 game moving average for FGA (black) and points (grey). I included a dashed line signaling his career regular season average in points (25.3) and FGA (19.7). As expected Carmelo started off slow in his career, which makes sense because he was a rookie adjusting to the NBA. He appears to have peaked around his 200th game and outside of his rookie season his output reached its nadir around the 30 game moving average of 550, which coincides with his first season with the Knicks. Throughout his career his FGA and points seem to mirror each other, which also makes sense--you gotta take shots to make shots.

But if you look closely at the chart something else emerges--Carmelo needs a lot of shots to score all his points. Since he began his career with the Knicks (around what would be 550 on the horizontal axis) he appears to score only about five more points that FGA. Considering that he only averages about 3 assists a game this could challenge his efficacy as on offensive player.

But points and FGA can belie actual performance, especially if a player's teammates are of limited offensive means. The 2013-14 Knicks were certainly one such team as they had to rely disproportionately on Carmelo for offense. Opposing teams knew this and, thus, made it more difficult for him to succeed offensively. 

Plus/ minus is a very rough measure of overall performance but it does give some context as to the effect the player had on the outcome of the game while he was on the court. Carmelo's career plus/ minus average is 2.4 and the chart below shows that his 30 game moving average peaked at 7.9 and bottomed out at -3.5. Interestingly if you compare the chart below with the chart above, especially early in his career, Carmelo's plus/ minus appears indirectly related to his point/ FGA. In other words, the more he shot and scored the worst plus/ minus he had. 

Over the last 150 or so games of his career (almost his entire time with the Knicks), Carmelo seems to have fallen into a zone that hovers right around his career plus/ minus average of 2.4. In light of his prolific scoring, it is fair to question if a player that contributes just less than 2.5 points to the outcome of a game is worthy of the 'superstar' designation. 

Looking at just one player is limiting as it grants no context in comparison to the performance of others. As a result, I created the same charts for The superstar--LeBron. There is no comparing the two players as by every objective measure LeBron is a superior player. However, if a player, like Carmelo, is deigned a superstar then his performance should be measured against the highest criterion--LeBron.

For LeBron, I pulled the same data from and conducted the same analysis as I did for Carmelo. (Because LeBron has player one more season, he's played at least one minute in 842 regular season games.) The chart below shows LeBron's career regular season 30 game moving average for points (grey) and FGA (black). There is clearly a wider margin between the two lines than there is for Carmelo, which indicates that LeBron needs fewer shots to score points. In fact, by the time he reaches Miami (around 500 on the horizontal axis) he appears to score 10 more points than FGA. 

The final chart shows LeBron's career 30 game moving average for plus/ minus. LeBron's career regular season average plus/ minus of 5.4 is clearly negatively skewed by his early days in Cleveland. In fact, during his last few seasons in Miami he appears to have a plus/ minus consistently between 5 and 10. (Not to mention an exceptional plus/ minus peak of 14.9 toward the end of his first stint with the Cavaliers.) 

While LeBron was certainly surrounded with better talent in Miami than Carmelo was in New York during the 2013/14 season, one cannot ignore that LeBron's 30 game moving average plus/ minus over the last few seasons hovers around Carmelo's career peak. Again, the point isn't to compare Carmelo and LeBron as individual players. The point is to give some context of the performance of one player perceived as a superstar (Carmelo) with the NBA's greatest performer (LeBron) based on empirical data. Further, all of this ignores marketing factors and fan popularity, which can play an equally critical role is designating a player as a superstar.

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