A description of what each Tactic may do can be found underneath the main tactic image in the game. For example some will increase the odds of receiving goal scoring opportunities, some will increase the odds of experiencing a better quality of shot at closer range and so on.
Please note: The game randomly 'rolls' before each match to determine the number of default opportunities given. The lowest number you can receive from each tactic is 1 but the highest number depends on which team you are up against and the initial random roll. If they are a top-flight team their defence will be strong so you may have less opportunities. If the game rolled a 0, and you bought the striker pro tactic, you may only get one opportunity. If the game rolled a 4 you'd maybe get 5 or more opportunities with that tactic equipped etc.
Here's a breakdown of the Tactics and what they offer as a minimum:
Beat the Defender - 3 opportunities, any dribbling position
Dead ball specialist - 3 opportunities, any freekick position
Pile Driver - 4 opportunities, any long shot
Goal poacher - 2 opportunities, any tap-in
Deadly striker - 4 opportunities, random selection