Upgrade Advisor

What Upgrade Advisor does

Upgrade Advisor is a CrownLab tool by CrownStats that ranks the 8 cards in a Clash Royale player's current deck by what their next level measurably changes — the interactions that flip, and how far the card sits below the rest of the deck.

Upgrade Advisor answers one question for a player's current deck: which of these eight cards is the most valuable to level up next? It reads the deck and card levels from the linked Clash Royale profile, works out what each card's next level would measurably change, and names one card together with the exact evidence behind it.

There is no 0-100 score. CrownStats sorts the deck by facts instead: how many direct card interactions change outcome at the next level, and how far the card sits below the deck's average level. CrownStats has no access to a player's Gold, Wild Cards, Elite Wild Cards or Evolution Shards — the Clash Royale API does not expose them — so Upgrade Advisor measures potential gameplay value under CrownStats' model, never whether an upgrade is affordable right now.

When nothing in the deck clears the bar, Upgrade Advisor says so — "Nothing urgent" — and shows what it measured instead of naming a card anyway. A recommendation nobody needs is worse than no recommendation.

By default only the current deck is analysed. An "Explore a Different Deck" option lets you evaluate one other eight-card deck built from cards you own — a tracked meta archetype deck or a manual pick — the same way. The tool never scans your whole collection.

What Upgrade Advisor analyses

• Each of the 8 cards in the player's current deck at its current level, with levels normalised across rarities so a Legendary and a Common are compared on the same scale
• The deck's average normalised level, and each card's gap below it
• Direct-damage and hitpoint interactions against CrownStats' supported card roster, before and after the card's next level — measured on the card's Evolution form when CrownStats can verify it is active in your current deck, otherwise measured conservatively on the base form
• Whether each card could be checked as both an attacker and a target, so the tool can say how complete its own evidence is
• The percentage gain in damage or hitpoints that the next level provides, as evidence rather than as a ranking factor
• The card's Crown Tower damage before and after the next level, where the dataset reports a separate tower figure
• The card's on-death damage before and after the next level, for the cards that have one
• The lowest level at which each supported interaction first crosses
• Whether a card is already at the highest level CrownStats holds data for
• For a signed-in player with recent battles: which cards appeared in recent opponents' decks, so the interaction changes above can be marked as ones that player actually runs into

How CrownStats ranks your upgrades

1. A card is only considered if its next level changes at least 1 supported interaction outcome, or the card sits at least 1.0 normalised levels below the deck's average. A card with neither has nothing measurable behind it, and CrownStats leaves it out of the ranking rather than placing it low.
2. Cards that qualify are described in words, strongest first. "Major level gap" means 2.0 or more levels behind the deck average. "Strong case" means at least 5 interaction outcomes change and the card could be checked from both sides at both levels. "Useful case" means at least one changes. "Low urgency" means the card is behind but no outcome verifiably changes.
3. Cards are ordered by tier first — a major level gap outranks a strong case, which outranks a useful case, which outranks low urgency. ONLY between two cards CrownStats describes the same way does it then compare how many interaction outcomes change, then how far the card is below the deck average, then how completely CrownStats could check it, then the lower current level, then the name. The same deck always produces the same order.
4. A card can reach "Major level gap" with no interaction changes at all — a gap that large holds back every interaction the card takes part in, whether or not CrownStats can point to a specific one. The card's own entry always states how many changed, so the wording never implies evidence that is not there.
5. Across CrownStats' card dataset, a single level raises a card's damage or hitpoints by about 10% almost regardless of which card it is. That gain is real and it is shown for every card — but because it is nearly the same everywhere, it cannot tell two cards in your deck apart, so it is reported as evidence and takes no part in the ranking.
6. Crown Tower damage, on-death damage and each interaction's first crossing level are shown as their own separate categories and take no part in the ranking either. They answer "what else measurably changes?"
7. When the top two cards are close, CrownStats says so in words rather than presenting a near-tie as a confident pick.
8. When recent battle data is available for a signed-in player, CrownStats can also show which of a card's validated next-level interaction changes involve cards that player has recently faced. It is context, not a ranking input: it does not change which card is recommended or the order of the list.
9. A card already at the highest level in CrownStats' data is marked maxed and left out. If every card is maxed, or if nothing clears the bar, no recommendation is made and the measurements are shown instead.

Key terms

Upgrade case

CrownStats' description of what one card's next level would change, in words rather than as a score: Major level gap, Strong case, Useful case, Low urgency, or Nothing urgent. It measures potential gameplay value, not cost or affordability.

Interaction outcome change

A supported direct interaction whose result changes at the next level — for example a spell that now defeats a troop it previously left alive, or a troop that now survives a hit that previously destroyed it. Counted with the same rules Interaction Lab uses, so targeting reach and shields are respected and a matchup that cannot happen is never counted.

Level gap

How far a card's normalised level sits below the current deck's average normalised level.

Evidence completeness

Whether CrownStats could evaluate a card as both an attacker and a target at both levels. Complete means both halves were checked; partial means only one could be; unavailable means neither — which is a different statement from finding no changes.

Normalised level

A card's level expressed on a shared scale regardless of rarity, so cards of different rarities can be compared fairly.

Maxed

A card already at the highest level CrownStats holds statistics for.

Recent-battle relevance

For a signed-in player, a count of how many of a card's validated next-level interaction changes involve cards that appeared in their recent opponents' decks. A count over a recent sample, not a prediction of future opponents, and not part of the ranking.

What Upgrade Advisor cannot see

• Only the 8 cards in the current deck are analysed by default, and the explorer analyses one other eight-card deck at a time. Upgrade Advisor never evaluates a player's whole collection or ranks cards across many possible decks.
• CrownStats has no access to a player's Gold, Wild Cards, Elite Wild Cards or Evolution Shards — the Clash Royale API does not expose them — so Upgrade Advisor measures potential gameplay value under CrownStats' model, never whether an upgrade is affordable right now.
• The ranking counts direct single-hit interactions that CrownStats' dataset supports. A card with unclassified mechanics contributes no interaction evidence, and the tool says so rather than guessing.
• The "Major level gap" boundary at 2.0 levels is CrownStats' own product judgement, not a measured constant. It is published here so it can be argued with.
• Tier boundaries are lines: a card just below one and a card just above it are described differently over a single interaction. The card's own numbers are always shown, so the line is visible rather than hidden.
• The ranking reflects the current balance data in CrownStats' dataset; an upcoming balance change is not anticipated.
• It is a card-level model. It does not judge play style, matchup context or whether the deck itself is a good choice.
• Recent-battle relevance, where shown, is a count over the recent battles the Clash Royale API still returns — a rolling recent sample, not a career history and not a forecast of who you will be matched against next. A card you have not faced recently may still be the one you face next.
• Recent-battle relevance needs a signed-in player, a linked tag and enough recent 1v1 battles. Below that it reports that the sample is too small rather than reporting that nothing is relevant — those are different statements. It is shown for the active deck only.

Sample size and evidence

The ranking is deterministic — there is no battle sample behind it. Every interaction change and stat figure is one CrownStats actually counted from its card dataset and can name, never an estimate.

Every validated interaction change is listed, not a sample of them, and can be filtered to offensive or defensive. A card with no measurable change says so, and a card CrownStats could not evaluate says that instead — the two are never shown as the same zero.

When interaction evidence is unavailable for a card, the tool says so rather than ranking the card as though it had been checked and found wanting.

Where the data comes from

CrownLab reads a player's profile, current deck, card levels and recent battle log through the Official Clash Royale API. It combines them with CrownStats' own card-stat dataset (per-level damage, hitpoints and related values, kept current with balance corrections) and, where a tool uses it, CrownStats' aggregated deck statistics from the battles it has collected. Nothing is estimated from a source CrownStats does not have.

Every personal CrownLab result is computed on demand from the recent battles the Clash Royale API currently returns for that player — a recent sample, not a stored career history — so a result can change as new battles are played and older ones leave the log.

CrownLab recommendations, Crown Score and Upgrade Advisor's rankings are CrownStats' own formulas. They are not official Supercell ratings or recommendations, and they are not a measure of a player's raw skill.

The personal CrownLab tools run on the Clash Royale player tag linked to a signed-in CrownStats account. Interaction Lab needs no account and no tag.

CrownStats is an independent project, built and maintained by one developer. It is not affiliated with, endorsed by or sponsored by Supercell. Clash Royale is a trademark of Supercell.

Related CrownStats tools and pages

• Interaction Lab lets you test any single interaction the advisor counts, at any pair of levels.
• Crown Score folds the strongest current-deck upgrade case into its Upgrade Readiness pillar.
• Crown Coach weighs the top upgrade against your other measured findings.
• Card Explorer shows each card's stats at every level.
• CrownLab lists every CrownLab tool by CrownStats, with shared terminology and limitations.