How many possessions does an NBA lineup need to play before we are confident it is good?

Plus-minus data is at the bedrock of a lot of thoughtful NBA analysis. If I tell you that the Celtics have outscored their opponents by 153 points in the 350 minutes that Jaylen Brown, Marcus Smart, and Al Horford have shared the court this season (per basketball reference), then you might reasonably conclude that these players are doing something right when they are playing together. At the end of the day, a valuable lineup needs to have a good raw plus-minus score (points scores minus opponents points scored). If a lineup of players is, over time, consistently outscored by the opposing lineups then this lineup cannot be considered effective.

The key question is what exactly does over time mean? One of the problems with looking at raw-plus minus scores for lineups are that they are heavily effected by small sample sizes. Especially early in the season, a good game or two can make an entirely average lineup look like world beaters.

Continue reading “How many possessions does an NBA lineup need to play before we are confident it is good?”

Usage and True Shooting Tracker

I made a web app that allows you to see how the players on each team rate according to usage and true shooting. You can quickly get a sense for how players compare to one another and can sort by team or position.  The points are also sized and colored according to a player’s offensive rating, so you can see how much better (or worse) the team’s offense has been while they are on the court. The app will be updated as the season progresses so you can always see current stats.

As a bit of explanation, usage percentage is a measure of the percentage of possessions that a player “uses up” when they are on the floor. True shooting percentage is a measure of how efficient a player is shooting the ball.  It takes into account free throw shooting and the fact that 3’s are worth more than 2’s. High usage, high true shooting players are obviously really valuable.

Try it out!


(All data is courtesy of





Threes and Layups Season Simulator

Try it out here!


By clicking on “Try it out here!” at the top of this post, you will be directed to what I am calling the Threes and Layups Season Simulator.  As a bit of background, Dean Oliver coined the term “Four Factors” in his revolutionary book Basketball on Paper. The four factors are, shooting, turnovers, rebounding, and free throws and these factors can completely describe a game of basketball. My Threes and Layups Season Simulator allows you to not only see how any team is currently doing on the year in terms of the four factors, but also tells you  what would happen to their efficiency (as measured by net rating) and their expected wins if you adjusted a part of their statistical profile!

Continue reading “Threes and Layups Season Simulator”

Three Point % Predictions (Nov 27)

Have you ever wondered how seriously we should take hot or cold early season three point shooting? How many attempts would it take for a player to convince us that they have reached a new level in their outside shooting?

I was wondering the same thing, so I built a simple model using the 2016-17 season three point data. If you want to read a little more about the model, go here.

Below are the current three point percentage projections for all players with at least 20 attempts, as well as how the projection has changed from the beginning of the season.

Full Table of Projections

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