Unlike real life, video games are mathematical based softwares. This means there is a pre-programmed feature which tries to simulate an "auto-balance". This holds true in almost all types of games which involve simulated physics. Why do you think there are games that allow the user to choose "difficulty settings". Even in a game like NBA Live one has the option to turn on "momentum" and "increased fouls". Another example is in the practice mode of billiards.
Just go to practice mode in billiards here and you will notice that there is a "show path" mode. This allows the practitioner to see the path lines of the cue ball, object balls, collisions and so forth. That's an example of the software's mathematical calculations.
There have been a great number of times in which I started off with a big lead then predicted with astounding accuracy that my opponent was going to comeback, regardless of what rating he or she had. Whether they be a Steve Davis or a Botcher, most of my games have been quite close. I could recall a game in which my opponent only had the 8-ball left and I had 1 ball to go that was right at the center of the top rail. The thing that stood out the most was that I knew the odds for me winning this game was extremely slim because the 8-ball was practically inside the pocket but hadn't fallen in yet. I tried to top spin my ball into one of the side pockets but it didn't fall so I thought it was over for me. Nope, instead my ball had blocked the cue from the 8-ball. I ended up losing that game anyways but it took about 5 more turns for him to get an open look at the 8.
There are many games similar to the one I described above that I continue to play in as well as watch from others. Obviously if one whacks the balls all over the table the odds of fluking or scratching are higher. However though, I have seen too many high rated players who play with good control of the cue that seemingly get "luck" and/or "bad luck" in an almost predictable fashion.
I am not saying that all this is part of the software because the fact of the matter is that these games still require a lot of skill. But if there is an "Auto Balance" factor in the software's programming then I would probably think that the game has more control over "accidental" snookers and scratching than it has over no rail fouls. The software cannot control how much power or lack of in each shot you make. It does however have some control over the mathematical equations which try to simulate real physics. Video games aren't real and are only simulations of the actual thing.
If video games had all the natural laws of real physics then they would take up too much memory to be played online or in a computer. But obviously that would be impractical in terms of programming to say the least. That's why programmers have to narrow the properties to make a simulation playable. It's a simulation not the real thing and because it's a simulation the causes and effects of games are more predictable.
