2. O'Connell gives the Raiders the best chance to win
Regardless of your opinion of Jimmy Garoppolo as an NFL quarterback, we have plenty of evidence of what he can do as a starter. In ideal situations, like San Francisco where he is surrounded by All Pro talent at every level, he's capable of leading a team to the Super Bowl.
However, in more challenging situations like Las Vegas, he has struggled against elite teams like Buffalo and middle of the pack teams like Pittsburgh. Playing Brian Hoyer, even if Garoppolo is healthy but less than 100%, is a risky move because of his recent displays and struggles. O'Connell, based on his preseason performance, appears to be the best option at this moment.
Garoppolo seems out of sync with the system, and Hoyer lacks playmaking ability after losing a couple steps in recent years. In true Vegas fashion, it's time to roll the dice, put all the chips on the rookie, and see what he can do.