Treyarch has admitted that it wasn't "always good" at multiplayer map design, but that the studio has learnt a lot over the years.
These days the studio is "very concerned about pathing through the map," said Black Ops design director David Vonderhaar in an interview with Gamefront. "You want to make sure players can navigate the map in a consistent fashion. You want your main paths, to say, be wider than your flanking paths - tell a vocabulary in a visual story there."
"What we've learned over time is that we weren't always good at that. [But] we've gotten better at that and it's become just part of our DNA."
Vonderhaar thinks Treyarch's design sense has evolved over the years. "So you're seeing in the map packs this evolution of our thinking, and Annihilation represents exactly what we're talking about here."
"I think anything Treyarch does long-term will be more cognizant of it," he said.
This week Call of Duty: Black Ops became the biggest-selling game of all time in the UK, shifting 3,722,411 since its launch in November 2010.
VideoGamer.com gave the latest Call of Duty: Black Ops map pack a respectable 7/10 in its Annihilation review, saying "these are another batch of consistently entertaining maps built on the solid bedrock of sprawling architectural foundations."