The four factor concept comes from Dean Oliver.
Oliver believes four factors determine why a team wins or loses. The four factors are:
Getting to the foul line
A team is measured both offensively and defensively on these four factors.
The objective of the game is to score more points than the other team. And points come from made shots.
These could be 30 foot shots, layups, or free throws. Putting the ball in the basket is an important factor.
Shooting can be measured in several different ways. The simplest way is through effective field goal percentage.
A turnover is when a team loses its possession or gives the ball to the opponent before shooting or scoring. A good team values its possessions and doesn't give any away to the other team.
This is measured through turnover percentage. What is the number of times a team turns over the ball per possession.
Here's how to determine a team's turnover percentage.
If a team gains control of the ball on a missed shot or free throw, they're given a rebound. An offensive rebound is when a team gains control of their own missed shots or free throws.
If a team gives itself more opportunities to score, it has a better chance of winning a game. A team's ability to get offensive rebounds is measured by their offensive rebounding percentage.
Learn how it's calculated with examples.
If a team is fouled in the act of shooting or repeatedly throughout the course of the game, it gets to shoot free throws.
This factor is more about volume than efficiency. This means a team that attempts more free throws is better than a team that shoots free throws at a higher percentage over time.
This can be measured in a few different ways. See the different measurements here.
There isn't a right or wrong answer. In the past, Oliver has put emphasis on shooting or effective field goal percentage.
The best answer is it depends. Each team is different and unique. A team that has balance across all four factors, both offensively and defensively, is likely to win more games.
Remember: These factors are measured on offense and defense. A team can shoot well, but if can't keep the other team from getting offensive rebounds and getting to the foul line, it might not win many games.