As someone who used to work directly on the development of FOBTS and other hardware and software for bookies, I will provide some clarifications.
Fruit machines - AWPs - Amusement with prizes. Despite what people think there is no skill involved in beating them. They just pay out a fixed percentage, so basically you are paying for the entertainment of some spinning wheels and flashing lights!
Quiz machines in pubs etc.. - SWPs - Skill with prizes. The payouts are still based on percentages, as the amounts and difficulty of the questions will vary, but the outcome is in the hands of the player and their ability to correctly answer questions.
FOBTs - Fixed odds betting terminals. Exactly as they name described, they are set to a fixed payout, from memory around the 80% mark. The games do not work how you think, in a casino the house edge is that the wheel has 1 more outcome than the odds reflect. In a FOBT every time a user plays, the machine contacts a server for random outcome within the confines of the payout margin set for the machine, it will just provide a win or lose outcome of a certain payout, with no direct correlation to the real chance of what is happening.
sports betting. Trying to pick a winner is an almost impossible task, even the best struggle to do this. The name of the game is in how things are priced. The bookies use statisticians and compilers to make their book based on what they think the chances of each event are. The winning gambler is able to compile their own book more accurately, and then when they see their price is lower than the bookies, they pile in.
As an example, imagine a fair coin toss. Each outcome is 50%. The typical bookie would give you odds of 10/11 for each outcome, you might get lucky, but long term you will make the bookie rich. However, if you spotted the bookie had priced tails at 11/10 you would smash in. You may not win any individual outcome, but over the long term, you would expect to profit.