Service Error and FBSO


As a follow-up, here is a more advanced way to evaluate serving. FBSO is of course indicative of your opponent’s ability to win the point on the opening possession – but what many overlook is losing on the opening possession. What you see graphed along the y-axis is “FBSO efficiency”, meaning we subtract lost points on the 1st ball from those that were won – in the same way hitting efficiency is calculated rather than just Kill%. This is why some FBSO eff’s are negative. The labels you see are the serving teams.

Compared with Passer Rating, this viz shows the opposite relationship to service error%. While there are certainly team performances where opponent FBSO eff stays low even as team SE creeps towards 10%, the overarching trend suggests lower service error is associated with lower Opp. FBSO eff.


We see this trend again when drill down into player-specific data. Each circle here is a single match performance by the player and the resulting FBSO eff by their opponent only when receiving against the player. Players with fewer than 5 serves in the match were filtered out.

The idea of looking at the efficiency of your opponent winning the point on the first ball makes more sense than solely looking at passer rating – mainly because Nebraska probably hits better on a good pass than Rutgers does on a perfect pass. Therefore getting Nebraska to pass a 2.0 on a 4pt scale might mean they still win the point as often as Rutgers does while passing perfectly. So in that sense, if they both FBSO at .500, your “tougher” serving against Nebraska really hasn’t help you win points (and that’s what we care about).

**This general concept of the efficiency of winning the point is incredibly important moving forward. In this example, we’re looking at how the level of service error relates to your opponent winning or losing on the first possession. We could look at FBSO eff by reception quality – or transition eff by dig quality – or by type of set – or by where you attack from – or really anything!

I’ll refer to this moving forward as Win Efficiency, just meaning your (won-lost)/attempts with regard to a specific contact. But this is how we’re going to define value for each touch; how it affects your ability to win/lose the rally.