It is not a secret that passed pawns are one of the most powerful weapons on the board. A passed pawn can promote into a queen and this is something that happens in endgames more than often. But in middlegames, things are usually a bit different. When there are many inhabitants on the board the road for the pawn is not sweet and full of roses at all. Pawns rarely promote in middlegames; a more seen scenario is that it gets blocked or surrounded by enemies.