Pay attention not only to your own wrestling Style, but also to your opponent’s! Each Superstar has two Move-family icons listed.
The left icon represents the Superstar’s style (red). If your opponent’s Style (red on the Superstar card) matches your weak Style (blue on your Style card), they get a +2 bonus against you.

The right icon represents the Style the Superstar is weak to (blue). If your Style’s Strong icon (red) matches the Superstar’s weak icon, you get a +2 bonus against that Superstar.

In the images above, Steady Eddie would get a +2 against the Brawler, and the Brawler would get a +2 against Steady Eddie. These bonuses do not cancel each other out.
In Tag Team Matches, you compare the Styles between all the wrestlers in the match.