The way the algorithm works is just a calculation of both onpage and offpage measures. When it caches your website it
grades it and assigns each page an onpage penalty and an over all website penalty, then as it comes to your site from links on
other websites it grades them, and assigns a penalty to the offpage. Then when a search occurs it quickly measures website, onpage and offpage calculations for that searched term and the website that has the least amount of penalties and the most link juice coming in will rank number 1.
You can have a lot of penalties and still rank high by having a lot of link juice flowing to your site, and you can have no link juice flowing in to your site and you can rank high, by having no penalties. The latter only happen to non competitive keywords.
But the holy grail is having little or no penalties and a lot of link juice flowing in. The actual amount of component that can generate a penalty are quite staggering and is the calculation that takes place during the caching process. Some
- not having alt text on images,
- having links not surrounded by content
- Having even slightly duplicate content within your own site
- External duplicate content
- duplicate meta tags
should have at least 50 pages in googles index, they should have at least a pr1, they should not have to many links on the page unless they all go to your site. Additionally the best links to get are from authority websites. That means they have a
pr5+ which means google considers them an authority and they generally have plenty of juice to pass on to your website which will help increase your page rank, and your SERP.