Average Possession Length

Tempo or pace shows how a team prefers to play. A team’s style.

Do they play up-tempo? Do they like to slow it down? Do they play man-to-man defense? Or zone?

A lot of these questions can be answered calculating a team’s average possession length.

Average possession length is a closer look at a team’s pace. It’s a new metric, and KenPom introduces it in this article.

APL = a team's seconds on offense and defense

What does this mean and why is it important?

This metric tells you on average, how long a team has the ball. It adds to the character of how a team plays.

This calculation isn’t adjusted. It measures the entire possession meaning offensive rebounds count.

This is important because it can test assumptions about a team.

KenPom provides the following example:

If a coach insists he likes to run, his offensive APL is your personal lie-detector test.

If a coach likes to go up-tempo, but his average possession length is 20 seconds, that’s not entirely true.

It’s often assumed the team that controls the pace wins the game or gains an advantage. This also isn’t always true. A team controls the pace often times because it’s winning and not the other way around.

In more research, KenPom found that the offense is responsible for 86% of the variance in predicting a team’s average possession length.

This means the offense often dictates the pace of the game. It’s not meant to be taken as a fact. This should be examined on a game-by-game basis.

Think of APL as a decoration or ornament to a team’s style.

Examples

In the 2018-19 season, Virginia ranked 352nd in offensive APL at 21.0 seconds. Virginia’s average offensive possession against opponents last about 21 seconds.

Virginia plays patient. The Cavaliers seek the best offensive shot. Virginia also rarely turns the ball over, ranking 12th in offensive turnover rate.

This style caters to a low offensive APL.

In contrast, Arizona State ranked 52nd in defensive APL at 16.9 seconds in the 2018-19 season. On average, defensive possessions lasted about 17 seconds for the Sun Devils.

Arizona State’s opponents shot a below average percentage. The Sun Devils ranked 72nd in defensive effective field goal percentage. Opponents turned over the ball on about 19% of possessions and seldom got to the free throw line.

This all describes a style of higher defensive APL.

Other Style Components

Several other statistics contribute to a team’s style. These are covered in the Team Stats section.