Duplicate meta tags affect my rankings

Meta Tags are meant to give information to assist the Search Spider (not a human) decipher what your website is about and how to organize that information.A Meta Title tag is what would generally show up as the title of your web page in a search result.If you do a search on Google and look at the results. The information at the top of each of the results that is underlined would be information that the Search Spider found in your Meta Title for that page. Having the same title tag on more than one page, in your case the same fifty pages just confuses the Search Spider. It is not a human that looks at each page and can see that each one has different content. Instead it looks at the duplicate information and thinks you are trying to spam the Search Engine to get better rankings.