Wedbush analyst Michael Pachter thinks Call of Duty: Modern Warfare 3 will outsell Black Ops, which recently became the UK's best-selling game ever.
Gamespot reports Pachter believes Modern Warfare 3 will sell more than 20 million units, his estimate of Black Ops' lifetime sales.
Pachter thinks the franchise's strong fanbase of "17 million weekly active unique online players" will drive the latest entry past its precursors.
All this despite Pachter's warning that the introduction of freemium service Call of Duty Elite will send some past loyalists right into the arms of rival Battlefield 3.
Each of the last few entries in the Call of Duty series has outsold its immediate predecessor, and Modern Warfare 3 pre-orders are piling up faster than Black Ops managed.
Modern Warfare 3 is due on PC, PlayStation 3 and Xbox 360 in early November.