Need info about SA success percentages

[Booster]

Your speculating is reasonable and logical.

My opinion is purely based on percentages, because its a game setted with chances/percents to work. So, for example if success rate for free-kick goal without SA is 30% based, is reasonable to be higher chance with SA. Maybe 1-2-5-10% whatever, just could be higher.
You have right when said about counters. For example One-on-One Stopper and One-on-One Scorer. Then if the bonus is 5% for success, that should counter and nerf it to 0% advantage.

Why actually any moderator or game-owner not gives a real answer to this?