Understanding Serving – More Plus Liga Stats

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Statistics should be able to help us understand the game better so they we can make valid judgements about the value of particular skills and players. Most of the statistics we are familiar with don’t really help us to tell the story of the game in any meaningful way. We tend to measure things that are easy to see, or use scales that date back to the 70s and don’t have any real meaning. I want to understand that better, so I have been experimenting with different statistics. Here I will talk about serving, using the statistics from the current Plus Liga season as examples. Included are matches up to 30th September. Names mentioned are the top 4 in each statistic with some other notable names included.

Ace Percentage – Gladyr 19%, Wlazły 15.9%, Louati 13.6%, Malinowski 13.2%
**Semeniuk 5th, Kampa 9th, Janusz not top 10
The most obvious and widely quoted statistic for serving is number of aces. I don’t even like to acknowledge the existence of this useless statistic, but if we have to look at aces, we should look at ace percentage. The best ace servers in Plus Liga are Gladyr and Wlazły, and those two are the only players with more than 14% aces (for now, it is still early in the season). That means that this statistic does not account for 80+% of serves. Surely those 80% of serves have some value.

Break Point Rate – Louati 54.2%, Toniutti 48.6%, Janusz 46.7%, Malinowski 44.7%
**Kampa 6th, Gladyr 8th, Wlazły 9th, Semeniuk not top 10
The objective of serving is to create chances to win break points. Perhaps the break point percentage for an individual server is interesting in and of itself. Suddenly two float / hybrid servers (Toniutti and Janusz) are prominent. This suggests that aces by themselves are perhaps not a valuable as we might think. Serving is only one component of the break point phase and we should note that the top 3 on the list are all serving with the setter in the backrow, i.e. with a better blocking rotation.

Expected Break Point Rate – Malinowski 42.8%, Kampa 41.7%, Gladyr 39.2% Louati 38.6%
**Semeniuk 7th, Janusz 10th, Wlazły not top 10
The expected Break Point Rate takes into account all serves, using the same principle as the expected Sideout Rate does for reception. It measures the likelihood of winning a break point, excluding the effect of block, defence and counter attack, that is isolating the effect of the serve. Here we have another new list. This statistic ‘penalises’ service errors directly and ‘rewards’ servers who make fewer errors. Malinowski has a very low error rate for such a strong server. Gladyr has so many aces that his error rate of 27% is worth it. Wlazły rates poorly here because his error rate is 41%. That seems like it is important.

Opponent Reception – Wlazły 44%, Gladyr 46.3%, Semeniuk 50.7%, Malinowski 51.4%
**Louati 5th, Kampa 6th, Janusz not top 10
Expected break point does not necessarily tell us which serves are more difficult to receive because it includes service errors, i.e. serves that receivers do not have to receive. We could look look just at the opponent reception quality which we measure here by expected Sideout Rate. By removing service errors from consideration now we are looking at how difficult the serve is to receive when it goes in. Suddenly Wlazły is back on our list and top by a nice margin. When his serve goes in, it is extremely difficult to receive. Perhaps also because the receivers never know if it will go in or not.

There is a fair bit of overlap in the measures that we have seen, but if we really want to get to the serving part we need to remove the effect of blocking and defence (that means Breakpoint rate is not valid) and include the effect of errors. So my vote is for expected Breakpoint rate as the best measure of serving, with opponent reception rate to give a little better information. Ace rate is interesting just for fun.

Tagged Volleyball AnalyticsVolleyball StatisticsPlus LigaScience Untangled

The total of 82 practical Coaching Tips can be found here and here.

Read about the great new Vyacheslav Platonov coaching book here.


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