Last Updated on July 13, 2026 by Mat Diekhake

Understanding basketball analytics can be challenging, especially when different websites use different formulas and terminology. The HeatingUp Impact Index was designed to simplify player evaluation while still rewarding complete, well-rounded performances.

This glossary explains every term used throughout the HeatingUp Impact Index, making it easier to understand player ratings, compare athletes fairly, and interpret the numbers behind every score.

For the full formula and worked example, see the Impact Index calculation page.

Whether you’re new to basketball analytics or an experienced NBA fan, this guide provides clear definitions for every metric used in the HeatingUp Impact Index.

HeatingUp Impact Index

The HeatingUp Impact Index is a proprietary basketball metric that estimates a player’s overall on-court impact using production, efficiency, role, and playing time.

Unlike many advanced statistics that rely on complex play-by-play data, the HeatingUp Impact Index focuses on measurable box-score contributions while accounting for how large a player’s role is within their team.

Higher scores indicate greater overall impact.

Impact Score

The Impact Score is the final numerical rating produced by the HeatingUp Impact Index formula.

It represents a player’s estimated overall contribution after accounting for:

  • Scoring
  • Rebounding
  • Playmaking
  • Defensive production
  • Efficiency
  • Playing time
  • Team role

Players with higher Impact Scores generally provide greater value over the course of a season.

Role Tier

Role Tier adjusts a player’s score based on their importance within a team’s rotation.

Bench Player (1.00)

Players who primarily come off the bench.

Examples include reserve guards, backup forwards and rotational centers.

Key Contributor (1.05)

Players who play major minutes and consistently contribute, even if they are not the team’s primary star.

These players often finish games and play significant offensive or defensive roles.

Starter / Star (1.10)

Players who consistently start games and carry significant responsibility for their team’s success.

Superstars and franchise players almost always fall into this category.

Usage Tier

Usage Tier estimates how heavily a player is involved in their team’s offense.

Instead of using official Usage Percentage, the HeatingUp Impact Index groups players into broader categories.

Low Usage

Players who primarily finish plays rather than create offense.

Examples include defensive specialists and role players.

Medium Usage

Players who regularly handle the ball while sharing offensive responsibilities with teammates.

High Usage

Players who create a large percentage of their team’s offense through scoring and playmaking.

These players often face greater defensive attention throughout games.

Minutes Per Game (MPG)

Minutes Per Game measures how many minutes a player averages each game.

Players who maintain high production while playing heavy minutes generally receive stronger overall ratings.

Points Per Game (PPG)

Average points scored each game.

Scoring remains one of the largest contributors to the HeatingUp Impact Index but is balanced against efficiency and all-around production.

Rebounds Per Game (RPG)

Average rebounds collected each game.

Both offensive and defensive rebounds contribute equally within the formula.

Assists Per Game (APG)

Average assists recorded each game.

Playmakers who consistently create scoring opportunities for teammates receive additional value.

STK (Steals + Blocks)

STK combines:

  • Steals per game
  • Blocks per game

This single defensive statistic rewards players who consistently create defensive events that change possessions or prevent scoring opportunities.

Example:

  • 1.6 steals
  • 0.9 blocks

STK = 2.5

Field Goal Percentage (FG%)

The percentage of field-goal attempts that are made.

Higher shooting efficiency improves a player’s overall Impact Score.

Three-Point Percentage (3P%)

The percentage of three-point attempts that are successful.

Efficient perimeter shooting increases offensive value, particularly for high-volume shooters.

Free Throw Percentage (FT%)

The percentage of free throws made.

Strong free-throw shooters contribute more efficiently when drawing fouls.

Shooting Efficiency

Shooting efficiency refers collectively to a player’s:

  • FG%
  • 3P%
  • FT%

The HeatingUp Impact Index rewards efficient scoring rather than simply rewarding shot volume.

Offensive Production

Offensive Production refers to a player’s scoring and playmaking contributions.

Primary offensive statistics include:

  • Points
  • Assists
  • Shooting efficiency

Defensive Production

Defensive Production measures contributions that directly impact opposing possessions.

Within the HeatingUp Impact Index, this primarily includes:

  • Steals
  • Blocks

Future versions of the metric may incorporate additional defensive indicators as more reliable data becomes available.

Box Score Statistics

Box score statistics are the traditional statistics recorded during every NBA game.

Examples include:

  • Points
  • Rebounds
  • Assists
  • Steals
  • Blocks
  • Field goals
  • Free throws
  • Minutes played

The HeatingUp Impact Index is intentionally built around readily available box-score data, making it transparent and easy to verify.

Player Role

Player Role describes how a player is used by their team.

Two players may average similar statistics while performing very different responsibilities.

The HeatingUp Impact Index adjusts for this through the Role Tier system.

Rotation Player

A rotation player consistently receives playing time as part of a team’s regular lineup.

Most rotation players qualify as either Bench Players or Key Contributors.

Starter

A starter begins most games and generally plays heavier minutes than reserve players.

Starters often receive a higher Role Tier multiplier.

Franchise Player

A franchise player serves as the primary cornerstone of a team.

These players usually lead their teams in scoring, minutes, and offensive responsibility while consistently earning the highest Impact Scores.

Box-Score Analytics

Box-score analytics are advanced metrics created using traditional basketball statistics rather than detailed player tracking or play-by-play data.

The HeatingUp Impact Index belongs to this category, offering a transparent alternative that can be calculated from publicly available statistics.

Why Definitions Matter

Basketball analytics can quickly become confusing when different websites use different terminology and formulas.

By standardizing every definition used within the HeatingUp Impact Index, HeatingUp makes player comparisons more transparent and easier to understand. Whether you’re evaluating MVP candidates, comparing players across eras, or exploring advanced basketball statistics for the first time, a shared vocabulary helps ensure every Impact Score is interpreted consistently.

As the HeatingUp Impact Index continues to evolve, this glossary will be updated with new metrics, definitions, and explanations so readers always have a reliable reference for understanding the system.

See all Impact Index methodology articles.