Just FYI - Triangles of any sort are a continuation pattern (see http://www.investopedia.com/university/charts/charts5.asp)
however this doesn't mean a continuation of the previous trend but of the current trend (within the triangle itself) with the on exception being the symmetrical triangle.
I agree that pattern success rates change over time but here on this thread many people seem to consider technical analysis to be an exact science, which it isn't. It's a statistical science, one whereby we use past statistics to try and predict future probabilities to maximise returns. If it was exact, computers would take our jobs very quickly
