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Every number on Spindex comes from real bets we track ourselves, in real time, across 9 crypto casinos. This page explains exactly what we measure, how we compute it, and, just as importantly, what we do not claim. If a figure is on the site, this is where you can see how it was made.
Figures refresh daily from our live tracking tables and reflect a rolling 7-day window. They move as play does, so exact counts will differ from the moment you read this.
Spindex is an independent analytics platform for crypto casino slots. We do not run a casino and we do not take bets. What we do is watch the games: for every slot we track, we record the real bets landing on it across multiple casinos and turn that raw stream into a handful of clear, comparable signals, the headline one being Observed Return, also called Tracked RTP.
Observed Return is a measurement of how a slot is actually paying out across the bets we tracked, expressed the same way as a published RTP so the two can sit side by side. It is a live reading of reality, not a marketing estimate and not a prediction. You can see it in action on any slot page, on the hot slots board, and behind the slot rankings.
Everything starts with first-party data. Our infrastructure connects directly to the live bet feeds of the casinos we track and captures results as they happen, rather than scraping other analytics sites or accepting numbers supplied by operators. Today that is 9 platforms: Stake, Stake.us, Rainbet, Roobet, Gamdom, Shuffle, MyPrize, Duelbits and Winna.
Each captured result carries the game, its provider, the source casino, the bet amount, the multiplier, the payout and a timestamp to the second. Because we watch the whole public bet stream rather than a single account, the sample is large: across the last 7 days we logged roughly 1,000,000+ bet results, which works out to about 200,000+ new results ingested every day.
Raw results are only useful once they are aggregated. Our pipeline continuously rolls the incoming stream into per-slot statistics over two windows, the last 24 hours and the last 7 days, so every metric reflects a defined, recent period rather than an all-time average that would hide what is happening now.
We deliberately keep a live rolling window rather than an ever-growing pile. Metrics on the site describe recent play, which is what actually matters for spotting current behavior. When we say a figure covers 7 days, it covers 7 days, and it updates as the window moves.
For each slot we show two numbers wherever we can: the certified Provider RTP, which is the contract the game is built to over millions of spins, and our Observed Return, which is how it actually paid across the bets we tracked. The gap between them is the interesting part. Over a short window Observed Return will swing above and below the certified figure, which is exactly what you would expect from a game of chance, and seeing both keeps the reading honest.
A slot is called hot when it is paying out meaningfully above its own recent baseline, not simply because it paid someone big once. We compute a z-score for each game, comparing its current window against its rolling baseline, so hot is a statistical statement about deviation from normal rather than a hunch. The full method and its limits are laid out on the hot slots page.
A big win on Spindex is defined by multiplier, not dollar amount, so a 5,000x hit on a $1 bet counts the same as one on a $100 bet. That keeps the focus on how remarkable the result was rather than how large the bankroll behind it was. We tier every qualifying win and count them continuously: in a typical week the feed logs around 150,000+ wins of 10x or more, 17,000+ of 100x or more, and 2,000+ of 500x or more. You can watch them land on the big wins feed.
On provably fair casinos the underlying bet behind a win can be checked independently with the seed pair, which anyone can do with our provably fair verifier. That is the strongest form of verification available, because it does not require trusting us or the casino.
Not every slot is played the same amount, and a metric built on a handful of spins is not the same as one built on hundreds of thousands. A newly listed or niche game can show a wild Observed Return simply because too few bets have landed to mean anything yet. Where a sample is thin we treat the reading with caution and label its confidence rather than presenting a shaky number as settled. The more play a game sees, the more its Observed Return converges on its true behavior.
Being useful means being clear about limits. A few things Spindex will never tell you, because the math does not support them:
Every spin is an independent result from a certified random number generator. A slot that just paid 10,000x is no more or less likely to pay on the next spin, and no game is ever due. Our data describes what has happened, never what will.
Observed Return and hot-slot readings are observations, not systems to beat the house. They help you see where play is landing right now, but they cannot shift the underlying odds, which always favor the casino over time.
We track a large, live rolling window rather than every bet ever placed on every casino in existence. It is a broad cross-casino picture, but it is a sample, and we describe it as one.
Spindex is independent. We are not owned, operated or funded by any casino we track, and the tracking pipeline is fully automated with no knowledge of which casinos we partner with. The site is free to use and funded in part by affiliate partnerships, so some casino links and referral codes earn us a commission if you sign up through them. That arrangement never touches the data: rankings, Observed Return and reviews come from the numbers, not from who pays us. Full terms are on our Terms page, and more on the team is on About Spindex.
We hold our data to one standard: show the real numbers, and be clear about their limits. If you believe something on the site is wrong, tell us and we will look into it and correct it. Reach the team at contact@spindex.net or through the contact page.
Spindex is an analytics and information platform. We do not operate any casino or facilitate gambling. All gambling involves risk and slots are games of chance. Please gamble responsibly and never wager more than you can afford to lose. If gambling stops being fun, visit our responsible gambling page for support resources.