Cognitive Biases in Volleyball – Errors and Risk

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I was recently having a conversation about risk in volleyball. My own views on the topic are well known. My view is that many people misinterpret what the risks are (here, here and here, for starters) and what they really mean. The specific conversation I was having referenced a service error at the end of a Champions League final (coincidentally this match) ‘costing the match’. A better solution would have been a tactical serve that could have been coupled with a blocking tactic to win a point. However, if we were to analyse the situation to determine which alternative would actually have been the ‘riskier’, we would find that it depends on how you define risk. A strong serve maximises the chance to win the point, but also maximises the risk of losing the point directly. A tactical serve maximises the chance of not losing the point directly, but also maximises the risk of losing the point in the extended rally. So which option carries the greatest risk? Making an error is considered a risky behaviour, and but making an easy play that increasing the likelihood of losing the rally in another way is not. Why do we value the direct error differently than other methods of losing points?

I thought that the psychological field of cognitive biases might provide us with some clues. I found four common biases that seem to fit or contribute to this (false) understanding of errors. A broad list of cognitive biases and explanations is here. The Certainty Effect causes people to overweigh outcomes that are considered certain relative to outcomes that are merely possible. An error is certain to lose the rally, and as risk is associated with errors, risk compared to all the other possible outcomes seems to make errors certain. If we combine this with Hindsight Bias, the tendency of people to overestimate their ability to have predicted an outcome that could not have been predicted, “I knew they were going to make an error!”, and our old favourite Confirmation Bias, the tendency to search for or interpret information in the way that confirms one’s preexisting beliefs, “They always make an error in that situation”, we can see how errors could have become so central to our thinking about the game and to how to make particular kinds of decisions. Alternatively, it could simply be Loss Aversion, the tendency to prefer avoiding losses to acquiring equivalent gains. The pain of losing is psychologically about twice as powerful as the pleasure of gaining. It is better to avoid a service error than to serve an ace. And if you want to read about Regret Aversion, click here.

For the record, I rarely talk about risk in my own coaching. I don’t think it is the appropriate word because it carries an implication of error and I don’t like to talk about errors. I much prefer to talk about how to win points, or create point scoring opportunities.

More on cognitive biases in volleyball here and here.

For coaching presentations and webinars available on demand, click here.


  1. Serving in Volleyball represents an interesting skill when viewed through the risk lens.
    For context, in the old days a server would only loose the serve–not a point–when a service error occurred; the other team had yet to earn a point through their own service attempt.
    Let’s look at risk:
    1-If a match is on the line (set point, match point then reducing the risk of service error needs to be reduced. remember the receiving team still has to produce three good (great?) contacts to score a point!
    2-if the serving team were to loose a set or match as result of service error then making a tough low risk serve is the best choice ( serving spots, weak receiver, short…)
    3-if the serving looses the opportunity to win the set or match but has a strong receiving and subsequent serve rotation then the risk could be dialled up
    4-Serving his needs to be seen in the context of each rotation and subsequent rotation (of course there is no sure thing either)
    5-serve tough, so the points won outweigh the point lost when the serve is finally lost. Here being aware of weak and strong scoring rotations should lead to the development of other strategies.
    6-Risk can be quantified (an after the fact statistic) by the server must focus on the flawless execution:this serve is the only one that counts, right now


    1. Your 2. is exactly the topic of the article. Why do we value losing a point through an error more highly than losing a point through any other means? That is what I am trying to understand.

      To your specific points…
      1 – By giving the other team an easier serve you give them more chance to make their three contacts and make a point. So you have less chance to win the point than if you had made a tougher serve.
      2 – In this context, ‘tough’ is analogous to ‘risk’ just a different word. Increasing ‘toughness’ by definition increases risk because you are serving closer to the net, to the line, further from the players.
      3 – sure
      4 – risk can be ordered by rotation, but would also have to include the sideout rotation in between.
      5 – I don’t understand this point. This point seems to contradict the others.
      6 – risk CAN be quantified before the fact. that is exactly what you are doing in point 1 by saying reduce the risk of error. You should always focus on flawless execution, that doesn’t change.


      1. 1- Agree wth that, yes chance of making the side-out increases for the receiving team but they still have the execute three contacts instead of simply collecting the point and rotating to serve. Moreover, they have to get the ball past the block and floor defence–two more possibilities for a point
        2-you can serve tough without committing a high rate of service errors; a measure could be a reduced quality of reception or other stat, you can serve tough and have high rte of errors, you can serve easy with a low error rate and you can serve easy with a high error rate
        4- Agree, there are two-parts to each rotation
        5- a server who serves an ace then an error has a +/- of zero, a sever who serves 4 aces then makes an error would have a +/- of 3 and so on. Quantifying a server’s performance would be useful. Of course there are other factors at play when points are scored. Contrasting ace v error is also useful feedback. In addition, noting when the error occurs (critical point?, late in a set, after a break, after a long rally etc, will help the coach and player.
        Talking about probability–as opposed to risk–is probably more useful.
        Mark, can you–in a new blog post–elaborate about two approaches to creating pressure for the opposition: the “no risk it, no biscuit” approach (Bruce Arians, Tampa Bay Buccaneers coach) as opposed to the ‘low/no error in all phases of play” approach. Which is better? Does it depend on your personnel, the coaches own risk profile? Is a combination of the two approaches possible? What are some of the other considerations?


      2. to your 1 – there is no ‘but’ in that concept. The sideout rate already considers the number of contacts being made and the chance of getting the ball past the block and defence.
        The post you are responding to gives a pretty good precis of the risk/reward (ie cognitive biases largely drive how we view risk), as well as the linked articles. And this one


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