This site reports two complementary layers of performance from the same match data. First are the Hudl box-score statistics: counts and rate stats (kills, attempts, errors, aces, serve errors, passing ratings, digs, blocks, etc.). Second are Expected Value (EV) statistics: a derived, versioned family of linear-weights metrics that translate different volleyball actions into a common unit—estimated points.
Hudl stats (descriptive)
- They are direct tallies of events: who recorded a kill, who committed an error, who passed a “3”, and so on.
- They are essential for accountability and scouting, but they live in different measurement units (counts, percentages, ratings), which makes cross-skill comparison inherently difficult.
- Many familiar summaries (e.g., hitting percentage) are ratios with substantial variance when sample sizes are small; they can change rapidly from one match to the next.
EV stats (model-based)
- EV is an estimand: “How many points did a player’s actions plausibly add (or subtract)?”
- We compute component scores (attack, serve, pass, defense—and setting when the data supports it) and sum them into EPC (Estimated Point Contribution).
- Because each component is expressed in point-equivalent units, you can compare “value” across skills without forcing everything into a single percentage.
What the EV numbers mean
Statistically, EV here is an additive model with transparent weights. Terminal outcomes that directly win points (kills, aces, blocks) receive positive weight; outcomes that directly lose points (attack and service errors) receive negative weight; and repeatable, point-relevant “process” actions (serve-receive quality distribution, digs that extend rallies) receive smaller weights. The result is an interpretable point-scale summary:
APV (Attack Point Value): terminal attack outcomes (kills and errors).
SPI (Serve Point Index): serving pressure and serving mistakes (aces, errors, and in-play serves).
PRS (Pass Rating Score): the distribution of serve-receive quality (perfect/positive/negative/error).
DCV (Defensive Contact Value): rally-extending and point-scoring defense (digs and blocks).
SPV (Setting Point Value): setting contribution when setting attempts and efficiency are available.
EPC (Estimated Point Contribution): APV + SPI + PRS + DCV (+ SPV), computed only from components supported by the available match data.
Why EV is useful (and what it is not)
Hudl gives you a descriptive view. EV performs a constrained, explainable projection onto an axis aligned with the scoreboard (points). This helps you detect “hidden value” (e.g., modest kill totals but elite passing and defense), and it helps coaches reason about trade-offs (e.g., serving aggression vs. error cost) using a common unit.
- EV is not a grade, a ranking, or a moral judgment; it is an accounting model of point-like contribution.
- EV is not a causal claim (“this player caused X points”) and it does not adjust for opponent strength or rotation context unless those factors are present in the input stats.
- EV is only as complete as the recorded data. If a component’s inputs are missing (for example, serve-receive not recorded for a match), that component is omitted rather than treated as zero—so comparisons should respect what was actually measured.
For a quick refresher, see the Expected Value Primer. For navigation to lineups, reports, scouting, and data tools, use the Mission Control menu above.