Sunday at Levi's Stadium, the San Francisco 49ers began a difficult task.
The list of teams that have made it back to the Super Bowl after losing it the preceding year is not a long one. The list of teams that have shaken off that loss to win the subsequent Super Bowl is even shorter.
San Francisco's quest to buck those historical trends got off to a shaky start. After building an early lead, the 49ers fell to the Arizona Cardinals, 24-20, and that loss exposed some problem areas that could potentially keep them from making another deep playoff run in 2020.