L20, Player Coupling

Question 1

Objectives:

• To investigate 1v1 player interactions and their role in performance
• To introduce continuous relative phase as a measure of coordination

Answer 1

Take-home messages:

• Event data from notational analysis does not capture player interactions (continuous measurement needed i.e., player tracking or sensors)
• Complex systems applied to player couplings (e.g., does one player tactically lead)
• Relative phase introduced as a coupling measure
• Team sports trickier to model this way

Question 2

What are 2 pros and 1 con of hand notation?

Answer 2

+ Can record player, position, action and outcome
+ Inexpensive

• Requires summarising

Question 3

What are 2 pros and 2 cons of comupterised notation?

Answer 3

+ Allows time-stamping of events
+ Requires less processing

• More expensive than hand (hardware and software)
• Video and logged events can be linked

Question 4

What are the 4 challenges with player trajectories?

Answer 4

1. Multiple trajectories- Each 2-dimensional
2. Time continuous
3. Player movements are not independent- Interactions are important
4. Constrained by specifics of the task, individual characteristics and the environment

Question 5

What does a relative phase of 0 degrees represent (in-phase coupled oscillators)?

Answer 5

Both objects move in the same direction at the same rate

(Stable in-phase coordination)

Question 6

What does a relative phase of 180 degrees represent (anti-phase coupled oscillators)?

Answer 6

Objects move in opposite directions at the same rate

(Fairly stable anti-phase coordination)

Question 7

What does positive relative phase represent (varying phase coupled oscillators?

Answer 7

One object leads the movement; negative, the other leads

(Phase transition from -90 degrees to 90 degrees as lead object changes)

Question 8

Give an example of perturbations in a tennis rally (as coupled oscillators):

Answer 8

Systems switching between periods of stability and instability as a result of perturbations e.g., a strong serve or return that causes larger amounts of movement and instability

Question 9

Give an example of how perturbations might lead to a player winning a round (or instability becoming stable) in a tennis rally (coordination dynamics):

Answer 9

Good defensive play, stability re-established