So my theory is long term success in gambling is not possible but of course I could be wrong as I don't know everything. I'd like to have a respectable conversation about it. I'm not attempting to troll here, are you up for it?
So the first question, aren't the odds baked in on longshots? So if you bet on longshots you make x multiple of risk but don't the odds makers also know this and price everything to equal out on the long run?
The most direct answer would be - no. Teams that are top of their leagues basically play better football compared to teams down the list & when they play at home they have a clear advantage. Of course odds provided by bookmakers aren't actual representation of probability and they never give you the 'right' deal. I'm not that concerned with that as I compound odds within a multiplier. I want to have a good return vs risk, find matches that suit criteria and position appropriately, the rest is taken care by luck, yes luck, as well as positive expectancy (Mayweather vs McGregor, who's more likely to win? Mayweather, Chelsea vs Watford? Chelsea). You have to back the more probable outcome as long as odds aren't overly short to make it worthwhile to bet on. Think of it as if you were to compound upon each winning trade ie risk 1pt stop on one lot to win 3 points net, you made $150, next trade will be 4 lots risking 1 point to make 3 points, etc. You won't always win 2-3 in a row, but when you do, well you do the maths
You don't even need to do longshots, do something like a single bet on a very likely outcome, start with £20 at average odds of 1.5 and compound, if u get 10 right you'd have made a return of 5,666% or x56 your initial outlay.