Hi Lorenzo,
Thank you very much for the updates! It was a CSS cache related issue after all. You might be able to turn off that option after a while, when the CSS files are emptied within the cache.
Well, the relevance algo evaluates matches based on keyword occurence:
– It selects N number of keywords from the selected fields. A keyword qualifies if it occurs X number of times.
– Then using these keywords it tries to find matches, starting from the most relevant.
This is basically it, with more calculations and tricks involved of course. Numeric values, like a year or something more complicated is not considered.
Sort-of, you could achieve something similar. The main difference is, that the search will only return items to a static keyword (same results for each page), and the algorithm is different – while the related posts plugin will look for keywrods within the current post first.