https://www.gamespot.com/articles/call-of-duty-black-ops-4-blackout-beta-adds-fast-c/1100-6461726/

Call of Duty: Black Ops 4's private Blackout beta rolls on for PS4, and developer Treyarch continues to make tweaks and adjustments to the mode each day. The studio has shared another post on Reddit outlining a new list of changes it's made to Blackout, including the addition of Blackout's first event playlist, Fast Collapse.

As its name implies, Fast Collapse is a faster-paced version of the battle royale mode. As Treyarch explained on Reddit: "The play space is constrained at almost double the speed as the base game. Scavenge fast and get on the move towards the safe area or you'll be caught on the wrong side of a nightmare."