It's only significant when compared to the paid to play one, which, obviously is in no one but the site owner's (another gambling profiteer like yourself) best interest. Like I've said previously I don't have any issues being wrong or corrected, and at this point I would much rather be wrong than spend 500 trials worth of bitcoins.
No it doesn't work like that. You don't get to say "it only becomes apparent when you compare it with the expensive thing", because it isn't true. Random is random.
You have the data for every single game, free or paid, after the game is over. You have a solid commitment to a board layout before it begins any game.
If there is any statistically significant deviation from random in the free game, it will show up in a large enough sample. It can't
not show up. You don't need to compare it with anything.
So. Now that we're clear on what it is you need to do? Go find the data. Until then you don't get to make claims like this.