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I have many years old website selling a service. The main keyword is 47% competitive, and we used to be #1 page 2, occasionally page 1 couple years back. Domain authority is double of any of the competitors on 1st page, followed root domain links is many times that of 1st page competitors, infact against some of them almost 10 times as much, MozRank and MozTrust higher too. Infact, every metric is higher than competition. Only metric which isn't as good is Followed vs NoFollowed links metric, 95% of our links are NoFollowed, but we are still #1 in external followed links. Yet we are stuck on 4th page, and on some localizations we are not even in Top 50. This has happened slowly over time, not a overnight thing. Page we are trying to rank for gets grade A for optimizations, yet we have less significant pages ranking higher for that keyword. Further, newer pages tend to rank better than old ones. The whole site actually ranks quite low and we are not even getting search traffic for long tail keywords.
No problems reported on GWT, Analytics etc. Is this a google penalization or something of the sort? How can i troubleshoot this and get past this?