When it is stated that any system is provably fair, it means that there is a set profit margin in which the system is going to profit for the owner of the site.  It is the same way in every casino across the world.  If you notice, there is never a casino which has went out of business because of the winnings they have paid out, they have went out of business because they were not able to bring the business into the casino.  The same goes with all these websites which claim provably fair.  They are going to make their % no matter what happens as long as people play.  So it is not fair stating that it is written in that if you play for a long period of time, you will loose; is a misrepresentation.  The issue with this is that if you play so long you will be back at the beginning of the system again.  Think of the system as a race track.  Most tracks have a start which also acts as the finish.  When you go far enough around the track you are going to end up back at the start again.  If you treat this track as the profit margin of some of these sites, there is a point when the system has given away the % thy are not to keep and give away as winnings.  If you are in the mix when this happens and the system starts to take the rake, then you will be caught in the mix.  If you play all the time, you will always get caught in that mix.