We are asked this question a lot and usually reply by saying that there are a lot of factors that make up a sites Google ranking.
If you have a website of 1,000 pages but no one is linking to it then it is probably safe to say that, it will not be as well ranked as a much smaller website (say 50 pages) that has more inbound links to it.
The fact that a website has a lot of pages, is of itself not enough to achieve a high google ranking.