The conversation around Oregon's Justin Herbert has to start with arm talent. While it is not his only worthwhile trait, Herbert's absurd arm talent is central to his game and enables him to get away with throws most other quarterbacks would not. It feels short-sighted to say arm talent alone defines any player, but in the case of Herbert, it is not disingenuous.
More so than the depth Herbert can heave the ball down the field, it is his blazing velocity which makes his arm such a weapon. No window is too small for Herbert to rifle a pass into.