If you said every team perform different in every match, it's mean sport is a luck based game, not skill based game. Skill based game means you need to have some skill to guess which one will win, so either they're play bad or good, your guess shouldn't be wrong.
Predicting a champion in league is completely hard, but usually it's not away from the top 3 favorited teams. But I'd consider to bet on a match, not predicting the champion.
What I meant is that in every match the team that you think would win the title uses a different strategy against a new opponent. They would try to attack on that weaker area with a different strategy. Sometimes it is effective and sometimes it is not depending on various aspects of the game. In most case your analysis doesn't work. That is the reason I only focus on a particular team and keep on betting the team regardless of the odds unless they keep losing back to back matches.