To Serve Or Not To Serve? – That Is The Question

Firstly, my sincerest apologies to William Shakespeare. That was uncalled for. Let’s move on.

Everyone knows that when you win the toss in volleyball you should choose to receive. That is as clear as my Shakespeare allusion was idiotic. For those who don’t know the reasoning behind it, the serving team must win one break point more than the receiving team in order to win a set. Given that it is very difficult to win a break point the receiving team has an advantage in any / every given set. There is, however, some suggestion that as the serving team has an extra opportunity to win that break point, the effect is negated.

During the off season, I was involved in a research project with Ben Raymond (i.e. I gave him some raw data and he researched it) that suggested (somewhat controversially) that timeouts were not as effective as we might think (all the links are here). When we were finished with that we started looking at some other things. The ‘serve or receive first’ question seemed like a pretty good question to investigate. If you want to go through all the data, click on this link. If you just want the executive summary, read on.

In the first instance, we took the average sideout percentage  for the Polish Plus Liga and ran a computer simulation of 10,000 sets. The simulation showed that the team receiving first won 4.4% more sets than the team serving first, 52.2% v 47.8%. Clearly it should be an advantage to receive first between closely matched teams.  The same holds, to varying degrees for any sideout percentage above 50%. This result seems to suggest that the between closely matched teams the value of having an extra chance for a break point does not (completely) even out the disadvantage

Knowing what we expected to happen, we then looked at actual events from the Polish and Italian leagues. Those results were interesting. The team receiving first won:

Polish Plus Liga – 50.1%

Italian Superlega – 46.8%

That is, in the Italian League it seems to actually be a disadvantage to receive first.  Why are the results different.  We came up with two possibilities.  Firstly, the sample size in each league was about 500 sets, a lot less than the 10,000 in the simulation. Secondly, in real life the teams do not have equal sideout percentages, one team is better than the other.

We tried to dig down a little bit deeper to see if we could find other factors. For example, did it make a difference if the set was close (three points or less).  Yes and no.  In Poland, the team receiving first won 54.1% of the time (as expected). But in Italy, they won only 43% of the time (the opposite of expected). That Italian league is apparently very strange.

When we dug down even deeper, we found that in the Italian League among similarly matched teams (teams 1-4 and 5-8 playing against each other) in close sets there was a strong advantage in receiving first (56.9%, 54.3%).  But this relationship didn’t hold in the Polish league. It is all very confusing, and surprising in the context of our simulation results.

So what can we say in the end? The receiving team should have a clear advantage over time, if not always in the short term. We can expect that the advantage is even greater in close sets and between evenly matched teams. Life doesn’t always happen as we expect.

A couple of other indicators we picked out of the actual data that could be interesting.

  • The team winning the first point had a roughly 57% chance of winning the set
  • If the team serving first won the first point, their chance of winning the set was over 60%. (Plus Liga 60%, Superlega 66%)
  • The team reaching 8 points first, had a 70% chance of winning the set. This increased to 85% if the margin was 3 or more points.
  • The team reaching 16 points first, had an 83% chance of winning the set. This increased to 92% if the margin was 3 or more points.
  • The team reaching 20 points first, with a margin of 3 or more points, had a 95% chance of winning the set.
  • If the sets were close (three points or less), all of the above indicators were less likely.

The legendary Platonov, now on iTunes.

https://itun.es/au/SNTxV.l

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2 thoughts on “To Serve Or Not To Serve? – That Is The Question

  1. Pingback: Zagrywać czy nie zagrywać? – Oto jest pytanie | At Home On The Court

  2. Pingback: Interactions In Volleyball | At Home On The Court

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