Probability might not always be in your favor. 25 is not a sample to consider. But, sites that require registration, may track your bet behavior and generate seed accordingly, though it might be boomerang as well.
If we have a server seed/client seed + nonce system then there is no way that a website can
always have the upper hand, as long as you decide to do your due diligence and change up your seeds at least once.
The nonce part of it cements that: stops them from changing server seeds on the fly and modifying the results to best favor the casino.