As long as the game is zero-sum or even negative-sum, you won't be able to make money. But, when you're placing tote bets, you're often competing against a var

As long as the game is zero-sum or even negative-sum, you won't be able to make money. But, when you're placing tote bets, you're often competing against a variety of different actors in a prediction market - and not all of them are pursuing a rational equilibrium strategy. These suboptimal or noisy agents can turn a zero-sum game into a positive-sum game, which is called subsidization. When participating in such a market, your primary goal is to extract value from these agents (very similar to arbitrage). It's important to note that the amount of subsidization needs to exceed the totalizator fees, otherwise you can't extract enough value. It's similar in poker, you're making +EV plays to extract value out of actors that are playing a suboptimal strategy. This is how some people can consistently make money. However, most people aren't rational robots, and are psychologically impacted by variance. All in all, I would recommend a different career path :)