Adjusted Efficiency

Offensive and defensive efficiency come directly from a box score. The four factors lead to the amount of points a team scores and how they choose to play contributes to the amount of possessions a team uses.

It's raw information. The raw offensive efficiency and raw defensive efficiency don't factor in competition.

Why is is this important?

Here are 2 additional examples of the importance of adjusted efficiencies using KenPom's analysis.

Take Gonzaga In the 2016-2017 season, Gonzaga's raw OE was 116.7. This ranked 6th amongst all Division-I teams.

Gonzaga plays in the West Coast Conference. Gonzaga's strength of schedule was 89th in the country in 2016-2017.

Gonzaga's AdjO was 118.4, 18th in the country, 12 spots behind their raw OE ranking.

In the same season, Cal State Bakersfield posted a raw DE of 91.5. This raw number is good for 3rd in the country.

Cal State Bakersfield is part of the Western Athletic Conference. Their strength of schedule was 152nd out of 351 teams.

The Purple Aces' AdjD was 93.7, which ranked 20th in the nation, 17 spots behind their raw DE ranking.

This is why adjustments are important. Competition.

Another Example

Let's revisit the earlier example of styles of play. We'll use round numbers to make it easier in this fictional example.

Virginia averages 60 possessions per game.

North Carolina averages 72 possessions per game.

The average college basketball game contains 70 possessions.

When North Carolina and Virginia play each other, what is the expected possessions of the game?

The expected possessions in this match up is 62.

Virginia plays 10 possessions slower than the national average. North Carolina plays 2 possessions faster. The sum is 8 possessions slower than normal.

Expected possessions = 70 - ((70 - 60) + (70 - 72)) = 62

A team's pace is determined by how they like to play and how their opponents like to play.

This is the reason efficiency numbers need to be adjusted. It accounts for competition or how a team and their opponents want to play.

Adjusted Tempo

In every game, each team wants to play at a certain pace. Adjusted tempo tries to tell you the pace each team wants to play.

For example, let's say North Carolina defeated Virginia 72-70.

Since we expected the game to result in 62 possessions, an adjustment must be made in the way each team wanted to play this game.

Both team's average possessions are adjusted to reflect the actual game pace. The actual tempo of the game was 3.25% higher than projected possessions.

Each team's average possessions is adjusted by this same percent increase.

This is the adjusted tempo. It's an estimate of the pace a team would have against the team that wants to play at an average Division-I tempo.

AdjT = Avg. Possessions adjusted by % increase/decrease of actual possessions

North Carolina's Adjusted Tempo is 74.34 possessions.

1% of 72 = 0.72 * 3.25 = 2.34 + 72 = 74.34

North Carolina would have around 74 possessions against a team that plays at the average Division-I tempo.

Virginia's adjusted tempo is 63.87 possessions.

1% of 60 = 0.60 * 3.25 = 1.95 + 60 = 61.95

Virginia would have 62 possessions against an opponent that plays at the average Division-I Tempo.

Each team's preference resulted in a game pace of 64 total possessions against each other.

How does this work throughout the season?

KenPom examines every Division I game with this formula. A season-long adjusted tempo results from averaging a team's adjusted tempo for every game played.

Adjusted Offensive & Defensive Efficiency

The same adjustments are made for offensive and defensive efficiency.

Let's continue with the same example and use fictional numbers.

North Carolina has an offensive efficiency (OE) of 110.

Virginia has a defensive efficiency (DE) of 110.

The national average for OE is 100.

North Carolina's expected OE is 120.

Both team's efficiency is plus 10 from the national average. This is why the expected OE is 120.

North Carolina's actual OE is 113.

Virginia's actual DE is 113.

The OE and DE are adjusted to account for competition.

The percent difference of the expected OE and actual OE is 6.01%.

North Carolina's Adjusted OE is 117.

1% of 110 = 1.10 * 6.01 = 6.11 + 110 = 116.611

North Carolina's OE would be around 117 against the average Division-I defense.

Virginia's Adjusted DE is 117.

1% of 110 = 1.10 * 6.01 = 6.11 + 110 = 116.611

Virginia's DE would be around 117 against the average Division-I offense.

Remember: Both teams have above average offenses and defenses in this scenario. Against other competition or average competition, it makes sense each would perform better.

Question, concern, or spot a typo? Please send me an email and let me know.

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