wc-player-ev — the atomic expected-points unit

Implements the xEV(player) formula defined in footballfantasy/context/frameworks/scoring-rules.md. Everything in this system that talks about a player's value — a strategist weighting a pick, the captain ladder sampling a candidate's distribution, wc-fitness-eval summing raw_xEV — ultimately samples the number this skill produces. So it has one job and must do it precisely: turn a scout signal (minutes model, npxG/xA, set-piece duty, card/rotation/injury risk) plus the round's fixture and clean-sheet signals into a player's expected points for this round, with the decomposition exposed so downstream agents reason about why, not just how much.

Two properties dominate every other term and must never be smoothed over:

1. The 60-minute cliff. The appearance tier is a step function, not linear in minutes — 59' and 60' are one point apart, and nearly every defensive/clean-sheet return requires the 60' threshold. A nailed-on starter banks this floor; a rotation risk's whole distribution shifts down and widens. Minutes security is the single biggest EV driver after goals.
2. The penalty / set-piece premium. A confirmed penalty taker and primary set-piece deliverer carries a structurally higher xG/xA than open-play numbers alone imply. This premium is large, position-agnostic, and must be surfaced explicitly (it is a top-3 focus on the FIFA strategy ladder and the reason a mid-price pen-taker often out-EVs a pricier non-taker).

This skill is the floor-and-ceiling factory. It does not decide captaincy (that sequencing belongs to wc-captain-ladder, which samples the per-player distribution this skill emits), does not score rank-relative fitness (that belongs to wc-fitness-eval), and does not derive its own clean-sheet probability or fixture difficulty (those are upstream signals — read them, never recompute).

When to invoke

• wc-scout chains into it to attach an EV to a player it has just profiled.
• Any wc-strategist genotype calls it per candidate player and then re-weights the output by genotype (A2 multiplies appeal by low-ownership leverage; A5 maximises the floor term; A4 leans on the fixture-scaled attacking terms against a weak opponent). The skill returns a neutral xEV; the archetype tilt happens in the caller.
• wc-matchday-tactician calls it for XI/bench ordering and to feed the captain ladder the distributions it sequences.
• wc-fitness-eval consumes the emitted player-ev signals as raw_xEV inputs — it must read them, not re-derive.

Workflow