Some NBA teams have reputations of being “balanced,” in which several players share the load and contribute roughly equally. Others are viewed as having one player who “carries” the whole team, shouldering the whole load. An illustrative example of this is the 2018 NBA Finals, where LeBron James single-handedly led the Cleveland Cavaliers all the way to the Finals, only to face a Golden State Warriors team which had a record-tying 4 All-Stars on its roster. The Warriors won 4-0, contributing to the narrative that a team is more likely to win a championship if it gets significant contributions from multiple players.

Methods of Data Collection

In this blog, I will explore the relationship between balanced teams and carried teams, both in the regular season and in the playoffs. I will mainly use the win-shares statistic from basketball-reference, which shows how many wins each player on a team contributed to the team’s overall win total.

For every season in NBA history, I used the following data for each team: how many games they won, how far they went in the playoffs, and how many win shares the top player had.

1. Success Based on the Best Player’s Production

1.1 Best Player’s Win Shares vs Win Total

It would be expected that there would be a strong correlation between the most win shares that a player has on a team and how many games the team won in the playoffs. For example, one would expect a team in which a player had 10 win shares would win more games than a team where no player had more than 5. However, while a correlation clearly exists, it is actually weaker than one might expect, with r^2 = 0.4892.

1.2 Regular Season Win Percentage vs Playoff Round Reached

The future exploration will involve look at relationships among regular season success. The following is the correlation between regular season win percentage and playoff success. The data here that will also be used for all future graphs is: 0 = no playoffs; 1 = lost in conference quarterfinals; 2 = lost in conference semifinals; 3 = lost in conference finals; 4 = lost in finals; 5 = won finals.

It’s clear that there’s a significant difference between the win percentages of playoff teams and non-playoff teams; after all, wins determine which team makes the playoffs. The surprising result is that there’s not much of a difference between regular season success and playoff success. This means winning games is a strong indicator of if a team makes the playoffs, but not so much for how they’ll fare in the playoffs.

Future Parts

The next parts will explore trends involving the percentage of win shares by top players as opposed to total win shares, and they will focus both on regular season and playoff success, and also on how they relate.