Reaction times and target defence

What we see, what's visible and invisible

In volley-ball the spectator's attention focuses naturally on the hits. From there, interpretations of the causes of success tends to remain centred on the hitting gesture.

However the hit is only the most spectacular and attention grabbing part of a complex action. It is the last link in a chain of processes, some of which are visible but neglected and others are invisible but just as important.

What we see, what's visible and invisible

Reaction time is absolutely key to the action in volley-ball. It is the time elapsed between the presentation of a trigger and the beginning of the response. This means the time required for the operations of information gathering, information treatment, selection of the physical move in response. It has been studied since the 19th century and many times since, in various experimental contexts.

This has allowed to establish certain amount of knowledge and models to enlighten intervention in volley-ball.

Reaction times and uncertainty

We distinguish between simple reaction time when a unique response corresponds to a unique trigger and choice reaction time when there are several possibilities of triggers and responses.

Simply passing from one to two possibilities increases reaction time by 58%! These are split seconds but in volley-ball they represent several metres of movement for even a very young player as we can see on the videos.

From this point we understand the tactical interest of creating uncertainty for the opponent and organising collectively to reduce uncertainty in your own side.

Treatment of information

It was demonstrated that attention capacities and information treatment abilities in a given time are limited. Thus, in ball sports, dual opposition or collective games, experts set themselves apart from beginners through more performing strategies of visual information gathering.

These strategies form an integral part of the technical abilities acquired by the players but they are missed by the simple spectator. It also looks like this accumulates experience enables them to gain time as they pre-select the most probable alternatives.

In volley-ball, learning to do is also at the same time learning to see and to chose. It means learning to select and prioritise relevant information, treating fewer facts, in the right order to act accurately and quickly.

Are you sleeping or what?

The state of awakening or alertness influences the time of reaction. In complex tasks like volley-ball, if the level of awakening is low, the reaction time is too long. A high level is best but beyond that, an excessive level of awakening (excitement, stress) disturbs the processes of information treatment and decision and therefore the performance. Moreover, the state of alertness is not a stable and permanent state.

Learning to play volley-ball is therefore learning to manage, over specific periods of play, optimal states of awakening and of alert physical availability. It is one of the forms of "self control" that we develop.

Reflex or automatic response

We often hear of a player that he has "good reflexes" because he is quick. In reality reflex actions are rare in sports activities. Reflexes are simple, archaic, pre-programmed and involuntary reactions to particular triggers. We can mention balance recovery or protection reflexes.

Paradoxically, the educational dimension of sports often rests on replacing ill-adapted reflex responses with more efficient controlled actions. For example on a fast or close ball (or block) pupils will have the protection consisting of closing their eyes. Later on they will keem them open to see the ball. Throughout the training, these responses will be automated through great practice volume.

Automation presents a dual advantage:

  • Take attention away from movement control (a player who has automated his movement will "no longer think about his feet " and will remain available to perceiving his surroundings).
  • Enable a shorter response time.

However, apart from the service which is a very specific task, a player is never twice in strictly identical action conditions (various times, distances, placements of the des different players etc.). Automation therefore cannot be the repetition of a stereotyped gesture or move, but the stabilisation of an approach both efficient and adaptable.

Back to top