Basic strategy is often abused. Players think they are adhering to it when they are not. And when you do not play basic strategy perfectly, the house edge cannot be lowered to 0.5%. Two of the most commonly misplayed scenarios are a hard 12 against a dealer 2 or 3.
Hard 12 is one of the stiff hands, meaning it is one of those hands with a high shot of losing but still has a shot at winning. In other words they are underdog hands. Basic strategy for those hands was calculated to give the play that would do the least amount of damage should the player lose. And, let