What is ZillaRank?
ZillaRank is a player-driven metric that provides data-focused coverage of the iGaming industry’s most popular games. First and foremost, ZillaRank represents a best-in-class analysis product for the latest releases spanning countless themes, genres, in-game features, and more. Games are rated against deep criteria, allowing our team to assimilate a list of the most lucrative and beloved slots in today’s market.
Unlike other slot-ranking systems you may have seen elsewhere, ZillaRank hones in on verifiable player activity. We don’t just accumulate and rate slots – we account for player preferences, feedback and relevance in the modern scene.
All rankings are based exclusively on publicly verifiable player behaviour, compiled using real-time data collection across regulated operators. No game can purchase or manipulate its rank in our system.
How Is ZillaRank Calculated?
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01ZillaRank accounts for a wealth of critical game-related factors, providing real-time results for players. Each slot is weighed against a carefully curated list of core game attributes relevant to modern users, with seven central elements at the heart of this tool.
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02All seven attributes are ranked by their significance to players. The more important a particular facet, the greater its impact on the game’s final ranking. Once all main aspects are totalled up, the game receives a ZillaRank score.
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03This score is designed to reflect the overall entertainment value, provable fairness, holistic payout potential, and the quality of the experience provided to players by the game.
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04To accurately tailor ZillaRank scores to players within each of our dedicated markets, we utilize unique calculators based on every region to assemble an authentic list of the most impressive games within that locale.
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05For example, while the UK and Germany may have the same games, players based in Britain might prefer a specific genre type over their German counterparts. As such, ZillaRank is developed to cater to a wide range of player interests within each region.
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06Our quest to present clear-cut ratings culminates in a consistently refreshed shortlist of the day’s best games, and points are credited based on the slot’s parameter-based performance. The lower the number associated with the slot, the higher the game’s quality.
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07In effect, a slot ranked ‘1’ is held in higher regard than a game numbered ‘10’, and so on. This results in a refined record of the slot industry’s finest output, all available for free at Slotozilla.
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08To objectively evaluate each slot, we use a special formula that takes into account key game parameters.
SR=W1*RTP+W2*V+W3*FR+W4*MW+W5*TS+W6*PR +W7*TGS -
09No two games are the same, and this is drawn out in our comprehensive analytics-centric scoring system for new and popular slots.
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10We implement an in-depth formula to better understand which slots are held in the highest regard by players, as well as which ones fall short of expectations. To ascertain where a slot sits on this scaled system, we contrast the game’s performance across the following seven touchpoints.
Key Criteria Descriptions
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RTP (Return to Player)This represents the amount of money a slot is expected to pay out over an extended play session, with games scored from 0% to 100%. Most games sit in the 95%+ region, which equates to around 95£ being paid out per £100 wagered. As RTP determines projected player returns, this metric carries significant weight in our scoring process.
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V (Volatility)Generally rated as low, medium, or high, volatility outlines the risk level associated with a slot game. Titles on the ‘high’ end of the scale will see fewer wins, while ‘low’ volatility releases pay out more regularly. ZillaRank incorporates an inverse scoring framework for this metric to showcase that ‘higher’ volatility delivers unpredictability.
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FR (Feature Rating)Most online slots comprise bonuses, multipliers, free spins and other special in-game boosts that seek to reward players during a play session. Often, these accoutrements are dubbed ‘features’ – and ZillaRank compiles bonus-adjacent information to accurately rank in-game perks. Higher scores translate to more rewarding bonus functionality.
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MW (Maximum Win)Although slots are devised with player winnings in mind, certain games integrate maximum win limits. This is generally included to reduce variance and protect operators. In terms of ZillaRank, this component earns increased ratings when linked to generous returns. Games that restrict users to limited ‘maximum win’ payouts are marked down on our scoring system.
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TS (Slot type)Slots traverse a breadth of themes, genres and payout options – all in the name of ingenuity and innovation. Progressive slots stand as the most profitable option for modern bettors. This game type adds continuous cash to the jackpot upon each spin, building to a crescendo upon the final payout. As a result, progressive jackpot slots garner more points on our scale than other verticals.
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TGS (Theme, graphics and sound effects)An all-new parameter devised to pay homage to the quality of graphics, thematic authenticity and in-game sound effects – ‘TGS’ supplies imperative information as to the immersion of a slot game. Between jolly jingles, atmospheric content and a game’s dedication to the supposed theme, there are ample threads to pull from here. While ‘TGS’ does not quantify a player’s potential winnings, it does establish solid context for the game’s holistic merit.
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Provider Reputation (PR)Certain software providers are renowned for high-performance graphics, others earn plaudits for payouts, and some contribute the most impressive in-game features on the market.
Reputable software providers reside within multiple regions, with top-rated teams licensed by recognized regulatory authorities. As unlicensed groups may have a propensity to mislead players, we regard ‘provider reputation’ as the second most important metric to account for when comparing slots.
The importance of parameters in the formula
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RTP9.0/10
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Volatility (Inverse)7.0/10
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Feature Rating8.5/10
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Max Win (Log Scale)6.3/10
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Slot Type5.0/10
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Provider Reputation8.0/10
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Theme/Graphics/Sound5.5/10
The weighting factors w_i are determined empirically.
| RTP | W1 | 0.25 (25%) |
| Volatility | W2 | 0.10 (10%) |
| Features | W3 | 0.2 (20%) |
| Maximum Win Potential | W4 | 0.10 (10%) |
| Slot Type (Progressive/Standard) | W5 | 0.05 (5%) |
| Provider Reputation | W6 | 0.15 (15%) |
| Theme/Graphics/Sound | W7 | 0.15 (15%) |
| Criterion | Designation | Recommended weight |
|---|---|---|
| Total | — | 1.00 (100%) |
- RTP (0.25) is the main financial parameter for conscious players.
- Features (0.2) and Theme/Graphics/Sound (0.15) are important for visual appeal and gameplay enjoyment.
- Provider Reputation (0.15) is a game from a good provider = trust + quality.
- Volatility (0.10) is important for a sense of balance in the game.
- Max Win (0.10) motivates risk-takers.
- Slot Type (0.05) is less important for the average player, but is taken into account.
Add example
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ZillaRank has already been put to the test in the real world, as our experts calculated a final rating for Pragmatic Play’s hit slot game, Gates of Olympus.
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Following all seven criteria, we found that Gates of Olympus is a top choice for contemporary bettors. The game scores impressively across all metrics, including RTP, features, design and provider reputation.
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Although Gates of Olympus was marked down for a limited maximum win limit (5,000x), the game remained strong throughout virtually all other parameters.
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After reviewing this slot and comparing it with others on the market, Gates of Olympus clearly outperforms most titles available today.
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Whether you’re after high-quality performance, leading graphical fidelity, consistent payouts, or all-around entertainment, Pragmatic Play’s popular slot provides all in abundance.
| RTP | 9.6 | 96.5% RTP delivers consistent payouts |
| Volatility | 8.7 | High volatility (only major shortcoming) |
| Max Win | 5.0 | Tumbles, multipliers, free spins |
| Slot Type | 2.6 | 5,000x max win |
| Provider Reputation | 8.6 | Standard slot |
| Theme/Graphics/Sound (TGS) | 6.9 | Pragmatic Play is a licensed and reputable studio |
| Criterion | Score (0–10) | Notes |
|---|---|---|
| Total | — | Highest among all reviewed titles → Rank: 1 |


