Keep in mind that some strategies may or may not work as you move farther up the skill level.
Let's say A counters B. But as you move up in rankings, someone of a higher ranking/skill level can execute B better than the person you beat before did.
Even though both players are using strategy B, Strategy A can only be used to beat one person.
Now this means one of two things, either strategy A is not viable and only worked cause you were facing a person with lower skill.
OR strategy A does indeed work but you executed it poorly yourself.
:)