Why getting aced hurts more than you think


We’ve used Efficiency Change in the majority of posts to identify where value is added or lost relative to expectations, but here I thought I would try to shave down the complexity of that metric.

The above viz looks at FBSO efficiency (won-lost on 1st ball)/(all receive attempts) in the left column – the percentage of each receive quality per team in the middle – and the product of these two in the right column to visibly look at how FBSO eff weights the distribution of qualities per team. These teams are again ordered by finish in the Big Ten and these numbers were built looking solely at conference matches.

Again, there’s a lot of cool stuff to look at within the viz but I’d like to draw your focus to to the righthand column: FBSO Eff * Percentage. This column sheds light on the impact of service aces that you may not have looked at before. As we’ve addressed before, using passing ratings is a terrible way to evaluate passing. In a passer rating, a receive error is a 0. This diminishes its true value and can make passers who get aced often look far better than they are. And thus, FBSO eff is a better way to evaluate passing.

But what you may not have considered is that because getting aced carries with it a FBSO Eff of -1.00, every single time, even a small percentage of aces can drastically impact your team’s receive efficiency. Illinois is unfortunately a good team to examine in this situation. They pass perfectly (R#) 22.8% of the time, which for them leads to an FBSO Eff of 0.331 – which is pretty decent when compared to the likes of Nebraska (0.354). On the other hand, Illinois is the second most frequently aced team in the Big Ten at 6.5%.

So while Illinois passes perfectly 3.5x more frequently than they get aced, these two receive qualities essentially cancel one another out in terms of FBSO. Perfect passes account for 0.076 of Illinois’ overall FBSO eff, while reception errors account for -0.065. That’s the gut-punch of getting aced. Aces carry a heavy potency per occurrence, with an ability to offset the value of much more frequent outcomes.

This is less of an issue if you’re Nebraska/Minnesota/Wisconsin because you spend so much time in good passing situations – and you hit for a great clip in those good situations. But if you’re a middle of the pack Big Ten team, you cannot afford to give up errors in serve receive – because you’re not making up for it in other areas like the top 3 are.

While this is likely just the beginning of the conversation about the value of contacts on this blog – take a second to really internalize what reward and cost of terminal contacts. If you jump to the Intro to Eff Change post, you’ll see how these terminal touches have big impacts, sometimes valued at more than a single point (your middle blocker acing JWO, a setting error on a perfect pass, netting on the block when your opponent is hitting out of system sets, etc). Just more food for thought to nibble on.