Not-$7 Study - Coin Flips
Just a reminder
$7 Studies are a running item on SmarterVolley. I started them in spring 2023 when I took a break from analytic-heavy content on SmarterVolley to focus on more qualitative aspects of coaching. To make sure I still got you all your fix of stats I launched the $7 Study feature where once a month I include some statistical research I’ve done. The goal is to give you a concise summary with a couple clear takeaways that you can digest in 10 minutes or less.
It’s also my pitch to you free subscribers! Hey, I put out a lot of content, and a lot of it is for free. If you’re a free subscriber and you read everything I put out and listen to all my podcast appearances, etc, you’ll pretty much get a feel for my way of approaching the game. But, if you’re busy and want to get right to some core takeaways, you’ll like these $7 Studies. In 10 minutes or less you’ll get at least one clear takeaway for your team, supported by evidence.
Previous $7 Study Topics
What attack patterns are most effective?
How effective are the blockers at each position?
How do setting choices affect opponent transition efficiency?
How does Make Them Play correlate to winning?
Does serve location influence where passers pass?
Do setters influence where passers pass?
Should passers consider where the setter is?
MTP Part 2
I’m titling this study a not-$7 Study and putting it out for free, because it’s more of a quick update to information I’ve already posted in my Rotations and Matchups Webinar, which I subtitled Small Gains, For Free.
One slide in that presentation was:
The recent NCAA Women’s tournament just concluded, so I figure I’d go through the 232 sets played and track whether the serving or receiving team won the set. And it turns out, it continues to be in line with what we already knew:
So again, we see that choosing receive makes you slightly more likely to win the set of volleyball. Even though this matches my previous study, I’m a bit skeptical that this is a “real” %. See below. But if it was…
A team that receives serve in the first set would have a 13.6% chance of winning in 3 while the serving team would only have an 11.1% chance of winning in 3. Once it goes to a 4th set, things are even. So again, if the effect was this big (which it’s likely not, again, see below), you would increase your odds of winning the match by 2% by choosing receive.
The real effect is probably bigger in deciding sets. There’s not nearly as many 5-game sets, so just analyzing Win % in 5th sets is going to introduce a ton of noise because the sample size is small. Eventually I’ll put together a big enough sample size to analyze that. But for now, just remember: choosing receive is the way to go in NCAA volleyball, and at some levels of club volleyball as well. At U12s? Serve all the way baby!
Some considerations about this study
In a neutral-site vacuum, I wouldn’t predict that receiving serve would increase your odds of winning the rally to 55%. You’re significantly improving your chance to win the first point of the match, which shouldn’t skew the Win % that much. There’s likely some confounding factors:
Better teams might choose receive more often. I don’t know the results of the coin flip from watching the video, I only know who received first. And about 1/3 of the tournament consists of early-round 3-0 sweeps. So if PSU, Nebraska, Wisconsin, Texas, Pitt, and Louisville all consistently choose receive and, for some reason, all the 15 and 16-seed underdogs all somehow have coaches that choose serve, then that’s going to skew things.
Better teams play at home more, and home court advantage seems to affect serving. So again, this might somehow mean the receive effect shows up more in relatively easy matches.
And the biggest thing: randomness. Even 200+ matches is a relatively small sample.