The history of the game. If people would just read on it, then they wouldn't be distracted by nonsense, like the law of the third/GUT.
The reason it doesn't work is because of the following:
1. The dealer doesn't block a number from hitting once it's hit or block numbers that haven't hit.
2. The same number of pockets remain on the wheel from one spin to the next. (Look down and count them.)
3. The odds of winning remains unchanged from one spin to the next.
4. The house payout is short. In other words, the payout out on a win will always be short of what the true probability of winning dictates as being fair. This prevents the player from being able to "step outside of probability" and exploit situations like the law of the third/GUT absurdity.
The numbers don't know if they've been "crossed" or if they should hit again, because they're not self aware, and they don't have a memory.
Over the years, many people have tried to test silly systems like the GUT, but along the way they find themselves playing the "if" game instead. "If I would have stopped here. If we would have bet this crossing instead. If we would have continued. If we would have bet more here." The "if" game is basically curve fitting. Sometimes it's intentional, but often times it's unintentional and the result of ignorance and denial. Whenever such systems are coded, the results have proven them to lose...as expected. Unfortunately this leaves the system designers claiming that it's not possible to code such a system because it doesn't take into account the "human element" in the way that hand testing does. In reality, what they really mean to say is that it doesn't enable the player to curve fit the testing results or lie about the results.
If you really want to beat the game, then read on the history of it. The information about how people have won is there. Don't be distracted by the nonsense. You can't side step probability in the random game of roulette.
-Dr. Sir Anyone Anyone