In invasion sports, such as basketball, it is commonplace to practice without a defender present.

But what is the effect of including a defender in practice?

Adam Gorman and Mike Maloney – two former skill acquisition specialists at the Australian Institute of Sport – investigated this question with highly skilled basketball players.

The study

12 basketball players (mean age = 17) from a national elite junior development squad participated in the study.

Players were required to perform 5 types of shots with either a defender present or without a defender. The type of shots included:

1. 3-Point shot.
   • The shooter received a pass from a partner. The partner then became a defender in the defended situations.
2. Free throw.
   • In the defended situations, a partner was allowed to step into the key in front of the shooter after the shot was made (as takes place in basketball).
3. Post move.
   • The shooter stood with his back to the basket. He then threw the ball into the air so that it bounced back into his hands. He was then required to turn and shoot without dribbling. In the defended situations, a partner was positioned behind the shooter.
4. Pull-up jumper.
   • The shooter dribbled the ball and executed a jump shot after receiving a pass from a partner. The partner became the defender in the defended situations.
5. Screen and curl cut.
   • The shooter began on the baseline and then proceeded to run around a chair positioned at the top hash mark of the key (acting as a teammate providing a block). The shooter then received a pass and executed a jump shot without dribbling. In the defended situations, the defender chased the shooter from behind.

Players performed 6 shots with a defender and 6 shots without a defender for each type of shot.

The results

There were clear differences between the defended and undefended situations, particularly for shot types where the defender could apply more pressure (e.g., the pull up jumper, and the screen and curl cut as opposed to the free throw). The key findings were:

When a defender was present…

• shooting accuracy declined for three types of shots – Post move, pull-up jumper, and screen and curl cut.
• shot execution time was lower for 3-point shots, pull-up jumper shots, and screen and curl cut shots.
• jump time increased for 3-point shots, pull up jumper shots, and screen and curl shots.
• jump time decreased for post move shots.
• ball flight time increased for every type of shot except for free throws.
• shot execution time and ball flight time was more variable. This suggests that players were constantly adapting their movements when there was a defender (which is an important skill in basketball).

Take home message

A simple method to increase the representativeness of practice in invasion sports is to include a defender when practicing skills. By including a defender, practice is more challenging as players are forced to continuously adapt their movements to new situations. This might facilitate the emergence of new and potentially creative movement solutions.

Importantly, challenging practice environments typically stimulates mental engagement (presuming the challenge is not overwhelming!) which is critical for learning.

Reference

Gorman, A. D., & Maloney, M. A. (2016). Representative design: Does the addition of a defender change the execution of a basketball shot?. Psychology of Sport and Exercise, 27, 112-119.