What Is A Good Serving Ace:Error Ratio?
We want our servers to be effective, but how do we measure effectiveness?
The NCAA box score tracks service aces (SA), errors (SE), and total attempts (TA). Aces, Errors, and Total Attempts are essential in determining a server’s effectiveness.
Aces matter, but knowing how many aces a server gets doesn’t tell us a lot unless we know the server’s total attempts and errors. In our recent article written by Dave Neeley, How Many Serves should a Volleyball Team Miss?, we see that the best individual servers on good teams were getting between 8-9% aces. The average was around 7%.
Again, aces alone don’t tell us how effective a server is because a weak serve can result in an ace simply because of poor communication, random passing miscues, or a serve hitting the tape and trickling over untouched. Knowing how many aces per serve attempt put those aces in perspective and gives us a better idea of a server’s effectiveness. For example, we can ask ourselves this question: "Who is the better server? Player A with 50 aces or Player B with 10 aces?" You might not want to answer that question until you know how many serving attempts Player A and Player B both have.
But what about errors? Dave’s blog noted that the best teams in the country miss around 10% of their serves, with the individual players on those teams missing in the 5%-15% range. So good servers, ideally, get roughly the same amount of aces as errors—typically slightly fewer aces than errors. Errors alone don’t tell us much if we don’t know the total attempts or aces. All players make service errors, even the very best, so some errors are justified. But we need to know if a player is missing too many, or not enough.
Combining Aces and Errors into a ratio is an easy and simple way to measure a server’s effectiveness. An Ace to Error ratio (A:E) of 1:1 or better is very good. The previous chart shows us that only one team in 2020's NCAA Sweet-16 had an A:E at or above 1:1–Minnesota at 1.2:1. No other team was even close to that ratio.
Now, instead of looking at the stats from the Sweet-16 teams, let's look at the stats from the top-25 teams in terms of total aces served all season long.
Once again, we can see that most of the toughest serving college teams have an A:E ratio significantly lower than 1.0. But that doesn't mean we still can't encourage the individual servers on our teams to accomplish this goal of having an A:E of 1:1. Here are the individual serving statistics from the NCAA champion, Kentucky:
Even though the team as a whole had an A:E ratio less than 1:1, there were a few players that exceeded that number, while also having a good Ace % and Error %, and a third player that was very close. As I scroll through the statistics of the other top NCAA teams, I see at least one or two players on each roster with an A:E of 1:1 or better.
A good goal for all servers at every level is an A:E of 1:1. A good server against weak competition, or at younger levels, might have a much better A:E than 1:1, but regardless of how good your competition is, a 1:1 A:E is a good goal. Ultimately, a server has little control over whether or not they serve and ace. You can hit a great serve and not get an ace, or you can hit a weak serve and two passers look at each other and let it land in the court. Service errors, however, are completely in the server’s control. No matter how good or bad the opponent is, the server can serve the ball in the court. Linking aces AND errors into a ratio provides a good balance between these two statistics and gives us a good idea of a server’s effectiveness.