pub const ZONE_DIFFICULTY_KNOTS: &[(i64, f64)];Expand description
Zone difficulty correction z(ch): how much harder (>1) or easier (<1) a chapter’s content plays than the honest per-fight scalar P/E predicts. The corrected ratio ρ̂ = P/(z·E) is a sufficient statistic for winrate: its 50%-crossing is ≈0.55 in EVERY zone (the stat-check contract “come with power” needs the ratio to mean the same thing everywhere).
Measured from sim runs on the current combat ruleset: per-chapter win
aggregates, weighted logistic fits per chapter band, z = band ρ50 / 0.55.
The drift it corrects is large and real — the same raw P/E can win ~78% in
one zone and ~11% in another, because mob ability kits and wave
compositions scale beyond raw stats. The map currently sits below 1.0
everywhere: the honest scalar conservatively drops the buff/debuff budget
shares of ability kits (see the ability_info closures), and that
undercount lands in z by construction. Pricing buffs honestly in the
scalar would move z back toward 1.0 — that is a future scalar change with
its own re-anchor.
Re-measure whenever mob kits, wave composition, or the combat package
change — the sigmoid_center grader gate is the staleness watchdog.
grade_pacing.py and economy_model.py carry mirrors of this table.