Baidu ranked the main reason for the decline of the analysis reproduced

When the search engine's algorithm changes or strengthens, causes some websites some keyword ranking disappears, some administrators say their website disappears. In fact, this is not the case, when the search engine algorithm changes or strengthens some pages are lost, or filter, punish some of the page rather than the entire site.
If all the pages of the site are gone (you can find the URL of the website directly in Google), it may be caused by the following reasons:
A. Your server is in a critical time of failure can not be normal access;
B. There are robots.txt problems with your website;
C. Because of improper optimization techniques, your website is purged from its index by the search engine;
If only a portion of the page keywords ranked down, or many pages of keywords ranked very poor. This could be:
A. Your improper behavior in the optimization method is found by search engine;
B. The search engine algorithm has undergone a major change;
C. You have done some violation of the search engine new principles or before the algorithm is allowed to change the rules, now is a violation, so on your site to a certain punishment;
Here are some detailed reasons:
1, from the basic start: Your server in the near future has not been normal access to the phenomenon?
A server that is not normally accessed is one of the most common factors that results in a ranking decline, so you do not have to make any changes to your site, just manage your servers and ensure normal access, especially at critical times;
2, if you have used the Robot.txt file, if so, have you recently modified it, resulting in a number of grammatical errors, which prevents the search engine index your site?
Error in Robot.txt code or robot.txt placement error can be a lot of unpredictable error factors, if you want search engine to ingest your entire site, you can not need to place robot.txt files, by default, the search engine will be included in your entire site.
3. Have you been optimizing your website lately? Potential errors that can be caused by internal modifications include:
A. Excessive optimization of a keyword, such as modifying Title,meta and other tags.
B. Internal link structure, especially the change of the link text, if it is to go out and modify the link structure and link text, it will be caught in the filter trap, especially the misuse of keywords, resulting in a keyword density is too large.
4, have you added a domain name to turn?
Sometimes the search engine is very resistant to re-steering, assuming that the re-steering is for optimization, use 301 instead of 302 to turn. This will be a very important tool if you redirect to the appropriate.
5. Do you have a certain number of meaningful links? Or is your link strategy "Come Today, go tomorrow"? If you use this strategy, you will get a good result. But if you add too many links to the small Web site you built, or too many link points to the same URL. Then you have a very good chance of being punished by search engines. As search engine algorithms are constantly improving, things that were previously applicable to today or no longer apply.
6. Have you established a link with a cheat site?
7. Is it punished for copying content? Some examples are as follows:
A. The same template is used throughout the site;
B. Use the same template as other websites;
C. Your competitor has mirrored your website;
D. redirect from an old domain name to a new domain name.
E. Over-reliance on robot.txt to guide spiders to collect your website;
8. Have you used cloaking to cheat search engines?
9. Does your website advertise on some large websites and has recently taken out the ads?
Advertise on some big websites, especially text ads. This will help improve your site rankings. Once the link is removed, the ranking will naturally fall with it.

Baidu ranked the main reason for the decline of the analysis reproduced