cattie - 11:40 am on Feb 19, 2013 (gmt 0)
From time to time I also notice some blogs have a rankings jump. When I took the time to reverse engineer those anomalies, I found legitimate factors at play, like a recent spike in twitter mentions, links or trackbacks from related blog posts. I found this even for older blog posts albeit less often.
Overall I wouldn't say that bigger sites or blogs have a free pass in search. After actually analyzing the anomalies that I have come across I would say that certain sites are better at generating the quality signals that Google is looking for.
For new webmasters having trouble ranking I would suggest they spend more time reverse engineering and testing new strategies. Once you figure out what Google prefers to see, its alot easier to give it to them.