Which casinos actually serve the best RTP builds: average RTP, shortfall against the best available build and how often each runs the top setting.
This is not a ranking of casinos by their own RTP, because casinos do not have an RTP — games do. What an operator controls is which build of each game it serves, and that is what we measure. For every title we observe at more than one casino, we compare the RTP each operator runs against the best build available anywhere in our set.
The result is a shortfall in percentage points, averaged across the operator’s measured catalogue. A casino running the best available build everywhere scores a shortfall of zero; one quietly serving 94% builds of games published at 96.5% shows up as a gap — and that gap is a price paid on every spin, not a one-off.
RTP shortfall compounds against turnover, not against deposits. Moving from a 96.5% build to a 94.5% one takes the house edge from 3.5% to 5.5%: the same play costs roughly 57% more. Over a few months of regular volume that difference exceeds what almost any welcome bonus returns.
It is also the one variable an operator can change silently. A licence is public, a payout policy is written down, but the build served in a lobby is invisible unless the operator prints per-game RTP — and most do not, which is the entire reason this measurement exists.
We only rank operators where we have measured at least twenty titles at two or more casinos, so absence from this table means insufficient coverage rather than a bad result. Sweepstakes brands run the same provider builds as their real-money counterparts and are measured identically.