Have you pressed the "bet" button, before the reels have stopped.. thinking that it will give you a favorable outcome on your bet? Well, I have news for you... the outcome has been decided in milliseconds after you pressed the button for the bet, the GUI interface happens long after that to display the outcome of the bet to you. 
(Go into the developer mode of your browser to see this)
What patterns do you see and how much do you believe in it?
(Go into the developer mode of your browser to see this) What patterns do you see and how much do you believe in it?
I strongly believe that these so-called patterns are made by the gamblers themselves in order to pacify the situation that they are facing. They are looking for ways to at least mitigate the damage as they are bargaining against themselves about it. When they see at least a glimmer of hope, they attempt to view it as a "pattern" and convince themselves that everything would be alright in the end.
Though this may be the case, I definitely agree with you that the outcome has already been pre-determined by the casino. Due to the presence of house edges, this gives the casino at least a tiny bit of advantage whenever you try to gamble on their respective platforms.
Back when I used to gamble, I used to believe that my every 3rd bet would win. So made bets that were divisible by the number of 3 and continued it. It at least gave me comfort but at the end I incurred significant losses.