Main battery formulas
Shell Grouping (σ)2
Max Horiz Disp134.5 m
Horizontal dispersion ellipse width at max range, from the verified WoWS dispersion model: $\sigma_H = \left(\dfrac{R}{30}\cdot\dfrac{\text{idealRadius}-\text{minRadius}}{\text{idealDistance}} + \text{minRadius}\right)\cdot 30$ $= \left(\dfrac{14717}{30}\cdot\dfrac{8-1.1}{1000} + 1.1\right)\cdot 30 = 134.5\,\text{m}$
Shell scatter width @ 10 km102 m
How wide your shells scatter at 10 km, from the same dispersion model as the max-range figure above. Picking a fixed range makes this number directly comparable from ship to ship: max-range dispersion makes a longer-range gun look worse even when it's tighter at any common range. The interactive Dispersion tab on the Charts card plots the full curve from 0 to max range.
Max Vert Disp80.7 m
Vertical dispersion ellipse height at max range: $\sigma_V = \sigma_H \cdot \text{radiusOnMax}$ $= 134.5 \cdot 0.6 = 80.7\,\text{m}$
Shell scatter height @ 10 km54.7 m
How tall the same scatter ellipse is at 10 km. Comparable from ship to ship for the same reason as the width value above.
Med Horiz Disp43 m
50%-hit horizontal radius: $\sigma_{H,50} = \sigma_H \cdot \text{GetHalfHitsRatio}(\sigma)$ $= 134.5 \cdot 0.32\;(\sigma = 2) = 43\,\text{m}$
Med Vert Disp25.8 m
50%-hit vertical radius: $\sigma_{V,50} = \sigma_V \cdot \text{GetHalfHitsRatio}(\sigma)$ $= 80.7 \cdot 0.32\;(\sigma = 2) = 25.8\,\text{m}$
AP Pen Close320 mm
Canonical community AP formula (jcw780/wows_shell), evaluated at muzzle velocity: $P = 10^{-7}\cdot K \cdot m^{0.69} \cdot d^{-1.07} \cdot v_0^{1.38}$ $= 10^{-7}\cdot 2609 \cdot 50.8^{0.69} \cdot 0.152^{-1.07} \cdot 841^{1.38} = 320\,\text{mm}$. Matches the in-game spec card.
AP Pen Far78.8 mm
Same formula at the ship's max firing range (18.4 km), where the shell has slowed to 304.5 m/s: $P = 10^{-7}\cdot 2609 \cdot 50.8^{0.69} \cdot 0.152^{-1.07} \cdot 304.5^{1.38} = 78.8\,\text{mm}$.
HE penetration25 mm
25 mm ≈ 152 mm caliber / 6 (standard HE penetration ratio).
AP overmatch10 mm
floor(152 mm caliber / 14.3) = 10 mm (AP auto-penetrates plating this thick or less).
AP AOE Radius15
AP shell over-penetration splash radius; scales with shell mass. Wickes 102mm = 3, standard 152mm CL ~ 20, Iowa 406mm ~ 270, Yamato 460mm = 400, Incomparable 650mm = 550 (max). Larger value = bigger splash damage area when AP over-pens.
Broadside guns used for alpha12
All 12 barrels bear on the broadside.
Turret turn time25.7 s
180 degrees / 7 deg/s traverse speed = 25.7 s.
HE full-salvo alpha25,200
2,100 HE damage x 12 broadside guns = 25,200.
AP full-salvo alpha37,200
3,100 AP damage x 12 broadside guns = 37,200.
Base HE DPM189,000
25,200 HE full-salvo alpha x 60 / 8 s base reload = 189,000.
Base AP DPM279,000
37,200 AP full-salvo alpha x 60 / 8 s base reload = 279,000.
Base shells/min90
12 broadside guns x 60 / 8 s base reload = 90.
Base fires/min8.1
90 shells/min x 9% fire chance = 8.1.
AA defense
Close-range AA DPS315
Sum across every AA aura on this ship of (aura.continuous_damage x 3.5 x aura.hit_probability). Here: (74×3.5×0.9) + (26×3.5×0.9) = 315. Covers AA-only mounts plus dual-purpose secondaries (Bismarck 105mm, USN 5"/38 cruiser secondaries) and dual-purpose main batteries (Sumner-class 5"/38, Akizuki-line 100mm). Formula validated against in-game captures on California, Sumner, Manfred von Richthofen, Dante Alighieri (exact) and within +/-17% on the remaining verified ships.
Maximum AA range5 km
Longest-reaching aura across AA-only + dual-purpose auras.
AA threat index1225
SUM over AA auras of (aura DPS x aura range km). A plane crossing the AA bubble is exposed to each aura for a time proportional to that aura's range, so long-reach DPS is worth more than the same DPS in a short bubble. Units: DPS*km; used to rank overall AA threat across the cohort.
Secondary battery firepower
Secondary DPM (per side)120,000
Sum across all secondary families of (per-side barrels × 60 / reload_s × alpha), where per-side barrels = mounts × barrels-per-mount / 2 (the guns that bear on one broadside target). Per-family: 4×2 102 mm (4/side) × 60/3 × 1500 = 120,000. Assumes every shell hits (real hit rate is lower; the Brawl matchup tool on the Compare page folds in dispersion + target armor).
Max HE alpha1500
Maximum HE damage per shell across secondary HE families. Best on this ship: 1500 from the 102 mm family.
Max HE fire chance6%
Maximum per-shell fire chance across secondary HE families (before target fire resistance is applied). Best on this ship: 6% from the 102 mm family.
Max HE pen17 mm
Maximum HE armor penetration across secondary HE families (caliber × 1/6 for most nations; 1/4 for German/UK BBs). Shells whose pen falls under a plate's armor thickness shatter for 0 hull damage though fire chance still applies. Best on this ship: 17 mm from the 102 mm family.
Damage Control Party
Sonar
Defensive AA Fire
Smoke Generator
Surveillance Radar
