There are a couple of series that performed amazing since chapter 1, IIRC Hokuto No Ken is the manga that had the most votes for its first chapter ever (memory might be foggy here, but IIRC I read it in Bakuman, if anyone remembers better please do say so), One Piece also must have ranked #1 since its first chapter because since its very first chapters it was almost always a top 5 manga and after chapters 12 almost always a top 3 manga if we go by the 8-week rule its first real rank was 4th with his 9th chapter.
Dragon Ball was also heavily promoted since its beginning, being the next manga after Dr.Slump its chapter 2 was #2, chapters 3 and 4 were lead color page, of course, we know how successful Dragon Ball also ended up being, but it was also heavily promoted without it already having achieved its merit because it was promoted in week 2,3,4, etc so they wouldn't have known how popular or unpopular it ranked (I know, I know.. Toriyama like Shimabukuro was a veteran at the time so of course it got better threatment).
But yeah.. what I'm saying is in both cases those titles just got promoted because of the veteran author or they must have a magic ball or something because it's impossible that they would know the results before chapter 3 was done haha