Explain how this is possible...

How does a website with an expired domain rank 2nd for a keyword that has ALOT of competition? i went from rank 5 to rank 8 because somehow this website jumped ahead of me as well as a youtube video that has nothing but thumbs down and spam comments, and another website that has loads of spun content and is obviously spamming.

I dont think google is reviewing websites for good content and quality backlinks like they say they do, because if that were the case i would be at least #3.

Explain??? any tips to overcome these bastads?

I'm curious about this too, it doesn't seem like good practice on googles part.