Contextualizing the On-Court Success of Kobe Bryant
The rise in popularity of all-in-one stats, such as PER and Win Shares, sparked debate over Kobe Bryant’s place among the basketball greats. PER is a rate statistic, and Win Shares is a cumulative measure that can be interpreted as the number of wins a player accounted for over the course of his career. Kobe ranks 16th in career regular season Win Shares, and 8th in career post season Win Shares.
To say Kobe was the 16th best regular season player and 8th best playoff performer in the history of the sport is not unreasonable. However, a number of fans, and former players and coaches, would argue that Kobe was comparable to LeBron James, who ranks 3rd and 1st in career Win Shares for the regular season and post season, respectively.
The argument often used to explain the gap between LeBron and Kobe in all-in-one metrics is that LeBron was far more efficient as a scorer, which is not entirely true as there are certain factors that influence scoring efficiency. The fluid rules of the NBA have strongly favored the offensive player in recent years, as shown by the graph below.
League-wide effective field goal percentage tended to be higher during LeBron’s prime seasons than during Kobe’s. While LeBron may have benefited from rule changes, that does not change the fact that he is easily one of the best players ever in the history of the sport at finishing around the rim, and as a result was indeed a more efficient scorer than Kobe. Due to their differences in shot type however, comparing Kobe to LeBron is not an apples-to-apples comparison. To really highlight Kobe’s brilliance on the court, it would make more sense to draw comparisons between players of a similar style. This was accomplished by looking at five metrics.
%FGA_Paint: percent of shots taken within less than five feet from the basket
%FGA_Interior: percent of shots taken within five to 14 feet from the basket
%FGA_Perimeter: percent of shots taken at 15 feet or more from the basket
AST%: number of assists divided by the sum of assists and field goal attempts
REB%: number of rebounds collected divided by number of rebounds available while player was on the court
These metrics were observed over an 11-season period from 1999 to 2010 , as many of Kobe’s prime seasons fell in this time period. The players considered to be the closest comparisons to Kobe are shown below.
Kobe’s proficiency in three areas — scoring volume, scoring efficiency, and passing — was compared to that of all other players who had a similarity index less than or equal to 15. The calculations for each of the three areas mentioned are the following.
Scoring Total: PTS_player - POSS_player*(PTS_league/POSS_league)
Points Per Used Possession: PTS_player / (USG%_player)*(POSS_player)
Passing Total: AST_player - (1-USG%_player)*(PTS_league/(POSS_league*(1-USG%_league)))
The “Scoring Total” and “Passing Total” metrics were divided by number of games played to obtain per-game values, which were then converted to percentile ranks, along with “Points Per Used Possession”. Based on these metrics, it is clear Kobe was a cut above his peers.
The above table shows how Kobe and his closest comparisons performed in the three metrics defined above during the regular season from 1999–2010. Kobe is the only player to have placed in the 80th percentile or higher in all three categories of scoring, efficiency, and passing. He is also the only player of his group to have an overall (average) percentile above 90. Granted, the period from 1999 to 2010 were some of Kobe’s best years; however, this period also coincides with the primes of other great players — including Tracy McGrady (dealt with injuries), Vince Carter, Paul Pierce, and Ray Allen — who all underperformed relative to Kobe in at least one of the three offensive metrics.
The same trends are observed for the post season.
Had a different subset of seasons been used for each player, Kobe likely would not have stood out as much. However, the fact that no other player with a similar style of play as Kobe could reach an overall percentile of 90 in either the regular season or post season over the given time period only serves to reinforce the basketball greatness of Kobe Bryant.
