Set up your table like this:

Pogo says: "To earn the Secret Blooop Badge, enter an Expert or Master room
and play the AI in a 1-point game without junkblocks. Remember to uncheck the
"Allow players to replace computer players after the game starts" in
the Table Settings. Defeat the AI and you will receive the Blooop Secret Badge."
If you are going to play against the "AI" (computer player) then you
should place your markers as shown in image one. The computer player will eventually
mess up and not drop a blocking marker in the empty space between number 2 and
number 3.