The stage was set for a tumultuous first half of the regular season before Ravens’ training camp even began. Quarterback Joe Flacco and running back Kenneth Dixon both sustained significant injuries while working out away from the team. Starting center candidate John Urschel abruptly retired. There have since been other injuries that have challenged the team’s depth. Players like running back Alex Collins, center Ryan Jensen and weak-side linebacker Patrick Onwuasor have emerged to fill voids. But through two months of the regular season, the Ravens haven’t been able to stop the seemingly endless cycle of encouraging highs interrupted by frustrating lows.