I don't know what formation you use, but make sure you have 2 MC's, as possession is really important and gives less "random" results. High white skills in your player and good defenders also makes games less random and more predictable.

In a match, look at the possession bar, how the simulation looks (e.g. do your players lose the ball often, etc.) and at potential yellow cards (this tells you that either the player is not good for this match or that your tactics aren't what the system set as ideal for that match). Learn to read what the game gives you and you'll have less randomness, more impact and better outcomes. However, it's a simulation game and randomness will always be a factor.