Every slot machine has a computer called Random Number Generator. The manner in which the symbols are appearing are determined by this computer. This is while it is beyond any slot player to say with certainty how the symbols will appear. It is this computer that decides that. However, it is the symbols that come after the spin of the reel that determines whether a player will win or lose.
The above fact is a secret that the casinos do not disclose to the players. The casinos do not produce slot machines. Rather they buy them from the producers. What the casinos can do is to fix the percentage of the payout as they want.
It is important for you to understand how the Random Number Generator abbreviated as RNG works. It is this computer that chooses the symbols that will appear after the spin. But it does that randomly and blindly. After choosing the symbols, it will merge them. It is the duty of the RN to choose symbols whether it is working or not.
When the spin button is click on by a player, the combinations that are obtainable are taken by the computer and then it also causes the reel to stop at the winning combination. What this means is that where the slot will stop is already known by the slot machine before the spin ends.
The symbols that are chosen have their different odds. This is because the casino will not have any house advantage if the symbols are to be of equal value with regard to their payout. If this is the case there is no reason why the casino should offer the slot games. The house edge the casinos have over the player is based on the fact that some symbols are less in value than others.
We can demonstrate this with an example. If the RNG were to be an archer that has been blindfolded and then the symbols are scattered randomly, he will definitely get at some symbols if he were to be shooting his arrows on the air. The probability is that he will be hitting at symbols that are more in number. In the case of slots, symbols with lower value are more than the higher value symbols. The above explains why the casinos have advantage over the players.
You should know that nobody can figure out with certainty what symbols the RNG is picking. The RNG acts blindly like the above archer that is blindfolded. RNG picks the symbols at random. From the above, it is clear that the RNG cannot be predicted with certainty by any slot strategy.