Archive for November, 2016

Lower nets = less rallies.

November 23, 2016

Even before becoming a dedicated analyst, I was interested in the numbers which provided me with a context for the decisions I would make with regards to balancing winning, court time, player development etc. One thing I brought up in recent conversations with coaches about junior girls volleyball, is how a lot of points are decided by serving errors and aces on a lower net (some competitions lower the net below 2.24M for younger age groups). It’s harder to receive a serve with a flatter trajectory and kids at that age aren’t developed enough to serve with a smaller margin of error.

Since everything should be quantified, I looked at the data I had collected over the last 4 years. I looked at the data from the last U15 girls team I coached, and compared it with other teams I had worked for as an analyst. What I found was startling. For most of the teams I looked at in various levels of comps across both genders, about 20% of the points they played was decided by  an ace or serving error. For my U15 girls over 8 games in that 2013 tournament 40% of the points they played were decided by an ace or service error! 40% – That’s twice as much as other levels of volleyball!

Women Total Rallies Ends in Ace or Serve Error % Ends in Ace or Serve Error
Norwood Alb-Wod U15G 2013 1002 398 40%
AUS U17 2014 1406 328 23%
AUS U19 2014 860 244 28%
AUS U19 2016 1894 436 23%
AUS Senior AVC 2015 1207 194 16%
AUS Senior WGP G3 2015 1188 197 17%
AUS Senior WGP G3 2016 874 178 20%
Men Total Rallies Ends in Ace or Serve Error % Ends in Ace or Serve Error
AJVC U19M 2015 1432 268 19%
Danish League 2015 2334 495 21%
Swiss League 2015 3801 825 22%

That means, for a sport strongly associated as being about “dig-set-spike”, our youngest female adoptees are only experiencing what the sport is about 3 out of 5 times. Everybody else is experiencing it 4 out of 5 times.

Is it good outcome for those teams and players?  Is it good for the sport? A Brazilian Federation had lower nets for younger age groups and tackled the problem by introducing rules in beginner competitions that the serve had to be underarm and had to be made no further back that 4m from the centre line.

In Australia, there’s been a persistent argument over the height of the net for younger age groups. The argument for the lower net is often for inclusiveness, that so that shorter kids can play “real volleyball.” While that might be true for the 60% of the time that some dig set spike actually happens after a serve, there’s the 40% of the time that the serve is either going out, into the net, or onto the floor, that is over and above what people participating in other levels of volleyball experience.

Does anyone else have data at this level of volleyball?