How NBA Teams Evaluate Players

By Liam Grealish

A Closer Look at How Advanced NBA Analytics Play a Role in Valuing a Player

Have you ever wondered how NBA General Managers know which players are right for their team to draft? It’s easy to want to watch college basketball prospects and rank them based on the eye test, however, this alone is unreliable. Just last summer, controversy was stirred when the Charlotte Hornets selected Brandon Miller with the second overall pick over NBA G-League Ignite star Scoot Henderson, who went on to be selected with the third overall pick. However, as we reach the end of the NBA season, it’s clear that Brandon Miller has outperformed Scoot in just about every facet of the game. So, what statistics are important to consider when trying to appropriately evaluate a player?

True Shooting Percentage (TS%)

The true shooting statistic is considered the best way to measure a player's shooting efficiency relative to their shot selection. For example, not every player on the court always has the same or even similar shot selection. For the “big men” positions such as power forward and center, most of their shots will come from around the rim, the most efficient shot in the NBA, resulting in a higher field goal percentage (FG%). Players at the guard position will have a larger variety of shot selections, thus taking less efficient shots by the standard FG% metric as they take shots further out from the rim. The true shooting statistic does this by dividing a player's points by two times the sum of a player's field goal attempts and their amount of free throw attempts multiplied by 0.44. In other terms: Points2(FGA+(.44*FTA)).

Effective Field Goal Percentage (eFG%)

Another effective way to conceptualize a player's shooting efficiency is the effective field goal statistic. Effective field goal percentage shows what players and teams have more success from the field. It measures efficiency by accounting for the fact that three-point shots are worth more than the standard two-point field goal. For example, a player who shoots 4/10 from the field with two three-pointers and another player shooting 5/10 with no three-pointers have the same eFG%. In other terms: FGM + 0.5(3PM)FGA.

Offensive Rating (ORtg)

Offensive rating calculates how many points per 100 possessions a player or team scores. Though other forms of this statistic exclude or minimize FTs and/or take FG% into account, they all have the same goal. Generally, when calculating an individual player's offensive rating, you don’t take these into account, unlike team offensive rating. In other terms: 100(Points)Possessions.

Defensive Rating (DRtg)

Defensive rating calculates how many points an opposing team scores per 100 possessions. Similarly to the offensive rating statistic, defensive rating can be used to measure both a player’s and a team’s defensive proficiency. Typically, the lower the defensive rating, the better the team’s or player’s defense is. Defensive rating, however, is more prone to flaws. For example, the Minnesota Timberwolves have the best defensive rating in the NBA right now, as their defense is anchoredtheir defense being anchored by three-timethree time Defensive Playerdefensive player of the Yearyear Rudy Gobert. However, their backup center Naz Reid has a lower DRtg than Gobert, even thoughwhen he isn’t the better defensive player. Though, the defensive rating still tells a good story for the most part. In other terms: 100(Opponent points)Opponent possessions.

Usage Percentage (USG%)

Usage percentage estimates the percentage of how many of a team’s possessions involve a particular player. Typically in NBA media, you see high usage used as a criticism ofto a player, when in reality it demonstrates how much offensive load a player can handle. Even if a player does not have the ball in their hands until the last moment of a possession, in which they take a shot attempt, their usage percentage will increase more than the ball handler that did not attempt the field goal. In other terms: 100((FGA + 0.44(FTA) + TOV + 0.33(AST))Possessions.

Player Efficiency Rating (PER)

Player efficiency rating is one of just about the best waysway to measure a player’s per-minuteper minute productivity. It takes into account nearly every statistic on the court into account, including points, rebounds, assists, steals, blocks, missed field goals, missed free throws, and turnovers. A player like Nikola Jokic dominates this stat because of how efficient he is in terms of scoring, rebounding, and playmaking, while he minimizes his turnovers..at the same time being very non-turnover prone. PER demonstrates how much of an all-aroundall around contributor a player is. In other terms: (PTS+REB+AST+STL+BLK)-(Missed FG + Missed FT + TO)Games played.

Box Plus Minus (BPM)

Box plus-minusplus minus calculates how well a team doesis doing whenwhen a certain player is or is not on the floor. It does this by subtracting opponent points scored when a player is on the floor from how many points the team scores when the player is on the floor. However, this statistic can also be flawed because it doesn’t account for a player's individual contribution like other statistics. For example, a player can record a +12 BPM without recording a single stat as long as that player’s team outscores the opponents while they are on the floor.

Value Over Replacement (VORP)

The value over replacement statistic calculates a player's contributions compared to a league-averageleague average player. This number accumulates throughoutover the course of a full season. For example, in the NBA, you would divide their stats by 82, for the number of gamesofas that is how many games are played in a calendar year. VORPIt combines a player's BMP with the percentage of possessions the player played in. In other terms: (BPM - (-2.0)(% of possessions played)(# of team games))82 <or # of games in a team's season>.