Every score should show its work.

01 · FOUNDATION

An AERC-like value for each canonical card.

The foundation prior converts printed Might and expected rules-text outcomes into one value scale, then subtracts the full Energy and colored-Power burden. Power is not free: recycling matching Runes also removes future Energy tempo. Popularity and collection ownership never change this stable card grade.

Resource cost = Energy + 1.15×Power + 0.25×Power×(Power−1)

Foundation = clamp(1.5, 9.8,
  5
  + 0.55×(printed Might + expected effects − resource cost)
  + flexibility + reliability
  − high-cost risk − explicit drawbacks
)

Expected effects use their real trigger window: play effects 100%, attacks 55%, defense 45%, conquer 35%, Hold 30%, and Deathknell 55% as neutral theory priors. Inside a deck, actual enabler density, opening-hand overlap, Rune reliability, and curve position replace generic optimism. Time Warp is expensive alone, but gains contextual value beside acceleration and a Hold/scoring engine that can convert the extra ready-and-score window.

02 · COMBINATIONS

Pairs and three-card packages remain explainable.

Pair affinity requires complementary traits, an explicit tag/card reference, or another reviewed mechanical connection. A shared region or legal domain is not treated as a combo. Three-card experiments are derived as 65% of their three pair edges plus a bonus only when the three cards close a real setup → resource → payoff chain. Resource collision, target competition, redundant top-end, and missing setup remain negative. In Deck Lab, selected anchors are checked against every legal completion on the user’s device.

• Synergy uses opening/early-draw reliability and diminishing returns.
• Antisynergy covers orphan engines, dead payoffs, curve/role gaps, competing trash consumers, early colored-Power collisions, and Rune demand.
• The curve prior follows Riot’s guidance: at least nine 2–4 Energy units and six interactive spells/cards in a 40-card starting point, while limiting 6+ Energy saturation.
• Legend, Chosen Champion, Battlefield, copy-limit, ban, and domain rules remain separate from card strength.

03 · DECK LEDGER

Foundation + synergy − antisynergy + fit + meta.

A deck’s ledger exposes each component and links every named card to its permanent card page. Card-by-card rows apportion the deck result back to the selected copies and list their strongest connections. Candidate recommendations compare the deck before and after adding a card, so “best fit now” can differ from “highest standalone grade.”

Candidate fit is decomposed into 30% foundation, 25% pair/triple package, 20% curve repair, 10% missing role, 10% Rune reliability, and 5% Legend/Champion/Battlefield context. Owned, not-owned, and unrestricted are hard filters rather than hidden score bonuses.

04 · TRUST BOUNDARIES

Browser-side theorycraft, versioned evidence.

Interactive scoring runs in the browser rather than consuming a scoring server. Deterministic shortlist, pair, and triple work uses the visitor’s CPU; card surfaces use compositor-friendly transforms and lazy rendering so the GPU handles presentation rather than pretending rules-text evaluation is a graphics workload. Public meta values stay neutral unless a complete, approved, version-matched calibration snapshot passes coverage and coefficient caps. Raw play rates, win rates, matchups, and source decklists are not published by this app.