Depends on their composure. If their composure is low, they're likely to miss loads of easy chances (Theo Walcott.) However, if their composure is high, they'll keep their cool and slot it away. When teaching Placed Shots, make sure the player has a high enough technique and finishing level. Otherwise, they won't be able to score again. For example, teaching Hazard or Gotze placed shots would fail epically, because their finishing is poor. However, if you teach somebody like M'baye Niang or Iker Muniain, you're likely to have more success.
Mental attributes are important in this game, and you shouldn't underestimate the importance of mental attributes. When looking for a poacher, I suggest you look for a striker who has more than 15 composure, or 13 minimum.