Counter-attacks mean you deliberately let your opponent control the ball, and as soon as they fail with an attack you try to make a fast counter-attack.  Playing counter-attacks could be a good option if you have a very good defence and attack (but a bad midfield), and especially in combination with your opponent having an ineffective attack.

Advantage: You can gain additional attacks (you get the chance to counter-attack when your defence has managed to stop an opponent's attack).
Disadvantage: You lose 7% of your midfield capacity.
Tactical skill is made of: The total sum of your defenders' passing and defending skills. Passing is twice as important as defending.

Only the team that is not dominating the midfield at the time of a failed attack is able to make use of the advantage of this tactic. If you dominate the midfield, then you will just suffer the disadvantage.  All counter-attacks are reported in match reports. There is also a slim chance that any team gets to counter, even if they don't select that tactic. These "tactic-independent" counter-attacks do not require the team to have an inferior midfield.