Indeed, even you did your research there are factors that can still affect the outcome, things that unforeseen when you place your bet, a good example if injuries happened during the game surely it affects the performances of the players or the team, it's something that can change the direction of the outcome.
There's no guarantee at you can assume and hope that with luck will be at your side after placing your bet.
Moreover, there is a red card when the match is in progress, this clearly affects the team from attacking to defending.
Have you ever experienced something similar? Of course I have and often the bet ends up losing because they lack players due to red cards.
It cannot be avoided just like that, you can analyze which players will get injured or get a red card then this is a factor outside of analysis, you can say the luck factor again is decisive.