Harker – Efficiency Change


Haven’t posted anything in a while, so thought I’d throw out an update on the Harker season as we’ve played about 70% of our matches so far.

For those who aren’t familiar with Efficiency Change, it is the idea of looking at the result you get, minus the input/the hand you were dealt. For attacking, you were given an input of a perfect pass but you then made an attack error – you took a great situation and came out with a terrible result.

For serve & receive, we look at our average FBSO efficiency and see if the serve or the pass has helped or hurt your chances to FBSO. So for Harker when we receive, our FBSO efficiency is 0.216 (this includes kills, errors, and getting aced, but factors out opponent service errors). If we pass perfectly, that number goes up to 0.396. If we pass poorly, that number drops to around 0.100. If we get aced, that number drops to -1.000. So we take the output (quality of receive contact, here perfect is 0.396) and subtract the input (average FBSO eff of 0.216); this means a perfect pass has a Efficiency Change of 0.396-0.216 or +0.180. That makes a perfect pass 0.180 points above our expectation. This is great.

So in that first visual, those are the attacking numbers from all of our matches. Here are the actual ways that we calculate input and output efficiencies:

Screen Shot 2019-04-09 at 11.54.28 AM.png

R is receive, D is dig, F is freeball, A is attack. Cover is…cover.

# is perfect, + is good, ! is medium, – is poor, = is error.

Again from that first attacking viz, you’ll likely see that Jarrett Anderson is consistently the attacker hitting above expectation. Billy Fan has evened out to a low positive – and Jeffrey Kwan hasn’t really been himself since getting back from the Best of the West tournament. Charlie Molin has steadied out as we’ve looked to get him more involved as a dump threat – and the next question is for the middle blocking positions. Vedanth has been too error prone is most matches, yet has had some big blocks in big games. Vance has steadied out as well over the last couple weeks and is figuring it out a little more. Liam is also in that mix though the final 4 matches were with him at outside. Brian Pinkston needs some more data to see where he falls, though he is easily the largest blocker in that position.

So just for context, if you’re looking at a perfect dig (D#, 0.403 on the Input_Eff table) and you take that perfect dig and smash it for a kill off a defender (results in a D=, 1.000 on the Output_Eff table) then the difference is 1.000 – 0.403 or +0.597. Which is great. However, if you take that perfect dig and smash it out of bounds, we end up with -1.000-0.403 or -1.403 which is horrible. You’ve cost us over a point because you had a great situation and turned it into the best outcome for our opponent.

From the serving standpoint:


Jeffrey Kwan has been our top guy. Likely because he is just so low error and our block and defense makes it tough to score on us even in-system. Our jump spin guys in Charlie and Jarrett have been hot and cold and can hopefully find some rhythm moving into the later third of the season.

Below is how well Harker does when serving at our opponent. When the opponent gets aced, Harker wins at 1.000. When the opponent passes perfectly, Harker wins at -0.158 (so really we lose). On average, every time we serve, we expect to lose at 0.115 via the Input_Eff table – meaning the other team should FBSO (including our service errors, at 0.115).

Screen Shot 2019-04-09 at 12.32.46 PM.png

Finally, from a reception standpoint:


Really the only guys to look at are Billy, Chris, and Jeffrey. They’ve been super steady throughout the season. It might be worthwhile to look at the breakdown by rotation to see if a passer struggles more in the left, middle, or right third of the court – or by the type of serve they encounter (spin, float, etc).

Here again is the breakdown specifically for those numbers:

Screen Shot 2019-04-09 at 12.45.24 PM.png

Hopefully we can dive farther into how we can boost some of these numbers in the coming matches as we gear up for playoffs!