In my previous post, Basketball Strategies 101, I provided a simple metric to measure the effectiveness of a team's offensive and defensive strategies. In this post, I want to describe Dean Smith's more sophisticated offense and defense measure that he called possession evaluation. This metric is described in detail with several examples in his book, Multiple Offense and Defense. This book is a must read for any basketball coach or player who wants to understand and teach the fundamentals of basketball.
What is a possession?
Coach Smith defines a possession as a team maintaining uninterrupted control of the basketball. The possession ends when the team no longer has complete control. A possession ends after every attempted field goal, trip to the foul line, turnover, offensive foul, and forced jump ball.
Let's highlight few examples when the change of possession occurs. After a team shoots they no longer have complete control of the basketball even if they recover the offensive rebound -- this constitutes two possessions. If the opponent forces a jump ball situation the possession is ended since neither team has control of the basketball. Even if the original offensive team recovers the ball after the jump ball situation, it is not uninterrupted ball control and counts as two possessions. When the offensive team is fouled and takes the ball out of bounds without shooting a foul shot, they maintain ball control and this is considered one possession. If a player is fouled during the act of shooting, the possession ends after the foul shot.
What is being measure?
Using this definition of a possession, a basketball team can quickly be measured for their offensive, defensive, and rebounding effectiveness. The average number of points per each possession measures a team offensive effectiveness. The average number of points for the opponents is used to determine the team's defensive effectiveness. The rebounding effectiveness is measured by the difference between the two teams total number of possessions (although this is slightly skewed by offensive fouls and jump balls, but it is negligible when compared to the total number of offensive and defensive rebounds per game).
While this reads like a stat collecting nightmare, in practice it is very little additional work over the statistics already being complied. Most team already record the number of shot attempts, so no additional work is required. A slight modification to the collection of foul shot attempts is the recording of the number of times a team goes to the foul line for a non-shooting foul. Finally, a new stat is required for number of times a team lost the ball without shooting. This last stat is the summation of offensive fouls, jump balls, and turnovers.
Putting it together
After each game the following chart(1) can be made.
| Your Team |
|
Opponent |
| _____ shot attempts |
_____ points |
|
_____ shot attempts |
_____ points |
| _____ times to the foul line |
_____ points |
|
_____ times to the foul line |
_____ points |
| _____ loss of ball |
|
|
_____ loss of ball |
|
| _____ total possessions |
_____ total points |
|
_____ total possessions |
_____ total points |
Offensive Effectiveness
Total Points / Total Possessions |
_____ |
|
Defensive Effectiveness
Total Points / Total Possessions |
_____ |
Offensive Ball Handling
Percent Loss Ball =
Total Loss of Ball / Total Possessions |
_____ |
|
Defensive Forced Turnovers
Percent Loss Ball =
Total Loss of Ball / Total Possessions |
_____ |
Rebounding Effectiveness
Total Home Possessions - Total Away Possessions |
_____ |
|
|
|
The key metrics are:
- Offensive Effectiveness: your teams average number of points per possession
- Defensive Effectiveness: your opponents number of points per possession
Coach Smith set his team goals to exceed .85 points per possession on offense while keeping his opponents below .75 points per possession. Offensive ball handling, defensive forced turnovers, and rebounding effectiveness were tracked, but rather than have a set goal, he used these metrics to determine why his team goals were or were not being meet.
While this evaluation system requires a little additional work, it can provide good insights to any coach that wants to increase their offensive and defensive effectiveness.
(1) Multiple Offense and Defense by Dean Smith
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