The hype machine. Usually it works quite well and tells exactly what a player is going to be. However, like most machines, it's susceptible to breaking. Sometimes it under-hypes a player and teams end up getting a steal. It also over-hypes players, giving some teams a complete bust.
Over-hyping doesn't always lead to a bust. Sometimes the player is still quite good, but they play nowhere near what they were supposed to be.
Here are the 20 most over-hyped prospects in NHL history.