In watching NBA games, I found that publicly available gamecasts are designed primarily for casual viewers. I set out to build a second-screen experience that offers a complementary perspective, one that goes beyond box score statistics and typical announcer commentary. The current design aims to reflect the mindset of a coaching staff, highlighting the key considerations that influence in-game decisions.
From a coaching perspective, the most immediate consideration is the lineup currently on the floor. The goal is to maintain balance in multiple dimensions: the mix of guards and bigs, and whether the group has sufficient size to match the opponent (see Ht – Height and Wt – Weight).
From there, the focus shifts to player roles and impact, whether the lineup is weighted toward offense, defense, or two-way contributors (see BPM). On the offensive side specifically, additional questions arise: are there enough creators as opposed to purely complementary players (see USG%), and does the lineup provide adequate shooting and spacing (see 3PAr - Percentage of FG Attempts from 3-Point Range and 3FG%).
Of course, the opposing team is making the same calculations, so their lineup requires equal attention. Using the same dimensions outlined above, the goal is to understand how their group compares, where each lineup holds advantages, where it is vulnerable, and how those strengths and weaknesses interact.
Are they playing a small-ball lineup against a backup center who cannot effectively punish it? Did they shift to a weaker defensive group when my primary scorer left the floor? Identifying these moments is critical to understanding where tactical edges can be created or lost.
The challenge, then, is how to exploit matchups and avoiding putting an unbalanced lineup on the floor, while also ensuring that key players receive adequate rest.
In the NBA, substitutions are typically planned in advance. Star players often know when they are scheduled to sit, and pregame planning helps address lineup balance by allowing coaches to evaluate all projected combinations ahead of time. From there, the plan can be adjusted as matchup issues emerge or as the flow of the game dictates.
As a coach, I rarely have a precise sense of a player’s box score production in real time. What I do have is a strong feel for how the team performs when that player is on the floor. If someone checks in for a four-minute stint and we surrender an eight-point lead, that stands out. The same is true for a player who brings energy and sparks a quick 6–0 run. Tracking a player’s +/- by stint provides a rough approximation of this intuitive evaluation.
Personal fouls are often the biggest disruptor of rotation plans. If a starter picks up a third foul two minutes into the second quarter, carefully constructed substitution patterns may need to be abandoned altogether.
Throughout the game, I’m also thinking ahead to the final minutes, specifically, who my best five players are and how to get them there. If those players are fouled out or exhausted when it matters most, at least part of that responsibility falls on me. That makes tracking personal fouls and minutes played essential as the game unfolds.
Until the end of the game, I rarely know the exact score, but I almost always have a strong sense of the time remaining in the quarter. I also need to be aware of the team foul situation, specifically whether either team is in, or approaching, the penalty. When a team is in the penalty, it becomes important to know the quality of free-throw shooters currently on the floor. Finally, understanding officiating tendencies and how to communicate with the referees as effectively as possible is an important part of in-game management.
Timeout rules in the NBA are complex, which creates opportunities for coaches to gain an edge through effective usage. Teams are required to take timeouts in certain situations and may forfeit unused timeouts if minimum thresholds are not met by specific points in the game. Well-managed teams use timeouts strategically, to halt opponent runs, set up after-timeout (ATO) actions, or preserve flexibility by deploying them before they are forced or lost.
NBA challenges are fundamentally an exercise in opportunity assessment. Coaches must weigh both the likelihood of a successful challenge and the potential reward. For example, overturning a foul on a three-point attempt carries significantly more value than correcting an out-of-bounds call. Coaches must also account for the cost of losing the ability to challenge later in the game, which is often a steeper penalty than the lost timeout itself. As a result, a marginal call in the first quarter may not justify the risk of being without a challenge for the remainder of the game. Even when successful, teams are limited to a maximum of two challenges per game. For a deeper breakdown of these decision points, see my timeout and challenge strategy page.