For each game of basketball we record dozens of stats- but which are actually useful to finding out “why” your team won or lost a game? Fortunately for the high school or AAU coach there are just four measurements that really matter. They are:
- Shooting, measured in effective field goal percentage (eFG%)
- Turnovers, measured in turnover percentage (TOV%)
- Rebounding, measured in offensive and defensive rebounding percentage (ORB% and DRB%)
- Free throws, measured in free throw rate (FTR)
In case you’re wondering, I didn’t just make these stats up- they were designed and tested by Dean Oliver, widely regarded as the creator of advanced statistics for basketball. He was the first ever statistical analyst hired by an NBA front office (the Denver Nuggets in 2006) and also wrote the book Basketball on Paper, considered the equivalent of baseball’s Moneyball. These four factors of basketball are based off his observations of thousands of NBA games.
Keep reading as I breakdown what these four factors mean and how you can apply them to make your team better.
Why the Four Factors?A team needs to be more efficient than its opponent to win- Dean OliverClick To Tweet
To break basketball down into it’s most basic terms, it’s a game about scoring more points than your opponent. Each opportunity to score is called a possession, and it’s from this definition that Mr. Oliver derived the four factors of basketball. There’s a really complicated equation to calculate possessions per game but we can make this easier on ourselves by just thinking about when a possession ends:
- After a shot is made
- After a shot is missed and the ball is rebounded by the defense
- After the ball is turned over to the other team
- After a foul that results in free throws
Scoring the basketball or getting to the free throw line leads to points for your team, so a high rate of possessions ending in these scenarios will lead to winning. Conversely, turning the ball over gives the other team a chance to score at the expense of your team, so it’s easy to see why a team needs a low turnover rate to be successful.
Finally, rebounding your own misses at a higher rate (offensive rebounding percentage) gives your team more chances to score. On the other end of the floor, defensive rebounding denies your opponents an offensive rebound ends their possession.
What’s important to note is that the four factors are about being efficient. They look beyond the raw numbers and highlight that basketball is a game about making the most of each possession.
Breaking Down the Four Factors
Shooting- Effective Field Goal Percentage
eFG% = (FG + 0.5 * 3P) / FGA
Shooting efficiently is the most important factor in winning as it directly leads to points. This is calculated by dividing field goals made by field goal attempts, taking into account the extra value of the 3 point shot.
Turnovers- Turnover Rate
TOV% = TOV / (FGA + 0.44 * FTA + TOV)
Turning the ball over without a shot attempt is the worst result of a possession. This factor can have a significant impact in middle and even high school basketball, where teams can struggle vs a press and turn the ball over more often in ways such as travelling, double dribbling and shot clock violations. Turnover rate can be calculated in many ways but I’ve decided to go with the measurement used in basketball reference.com, which divides the number of turnovers by a rough estimate of number of possessions.
Rebounding- Offensive and Defensive Rebounding Percentage
ORB% = ORB / (ORB + Opp DRB)
DRB% = DRB / (Opp ORB + DRB)
Getting a miss back not only leads to an extra shot attempt but often an easier close in look versus an out of position defense. Denying the other team these second chances is also equally important. These percentages are simply calculated by dividing the number of your rebounds by the sum of your and their rebounds on that end of the floor.
Free Throws- Free Throw Rate
FTR = FTA/FGA
Free throw rate is about the rate your team gets to the foul line. Interestingly, Mr. Oliver found that it was the rate a team got to the line, rather than the rate that they actually made foul shots that was more important to winning. This makes sense because shooting free throws also has other small benefits, like allowing your team to set up defensively and getting their players in foul trouble.
Analyzing the Four Factors
Weighting the Four Factors
The four factors aren’t meant to be considered equal. According to Mr. Oliver, based off a scale of 1-10, the importance of each factor is:
- Shooting percentage (10)
- Turnovers per possession (5-6)
- Rebounding percentage (4-5)
- Getting to the foul line (2-3)
Shooting at a high percentage is the most important factor, and half as important is limiting turnovers and rebounding at a high rate. Finally, getting to the foul line is least important.
A Case Study- Celtics vs Lakers Game 7 in the 2010 Finals
Everyone knows that the Lakers narrowly beat the Celtics, 83 to 79 in one of the most epic final game 7’s ever. This happened despite the Celtics shooting at a far higher eFG%- 0.451 to 0.349. Looking at the other 3 factors however, we see why the Lakers won. They greatly out rebounded the Celtics offensively and defensively and also got to the line at a higher rate (0.446 vs 0.239). The Lakers also beat them in the turnover battle, only turning it over 10% of the time compared with the Celtics’ 15%. You can check out the stats in the same template I designed for you to do your own four factor analysis.
The lesson to learn is that your team can be great in one factor and still lose, or be terrible in one but still win. I even think that this proves with stats what we coaches preach that “there is more basketball than scoring it”- as you can see rebounding, protecting the ball, avoiding fouling shooters, are all little things that when added up can win you the game.
Applying these Factors to Your Team
Although as of writing the school season hasn’t started yet, I’d highly recommend that you download the spreadsheet and input some results from your previous games into it. Sometimes the results will confirm your intuitions about how the game went, but you’ll also occasionally be surprised by the reasons you won or lost the game. Learn from your past mistakes and coach your players to be better in those areas. If you’ve got access to opposing teams box scores, you can plug in their stats in as well to figure out their weaknesses.
For now, that’s all I’ve got. I loved doing this piece because it was amazing to see how stats can lead to winning more games. I’d really likely to interview Dean Oliver to see how all his stats stuff applies to youth basketball and I’ll keep you all updated in the future.