"heading_match",
 "popularity_score",
 "incoming_links",
 "title_plain_match",
 "text_sum_classic_idf",
 "title_plain_unique_terms",
 "title_min_raw_ttf",
 "opening_text_plain_stddev_classic_idf",
 "title_plain_min_raw_ttf",
 "auxiliary_text_plain_sum_classic_idf",
 "text_match",
 "category_plain_min_raw_ttf",
 "heading_plain_min_classic_idf",
 "auxiliary_text_min_raw_ttf",
 "heading_min_raw_ttf",
 "heading_plain_min_raw_df",
 "text_word_count",
 "heading_stddev_classic_idf",
 "redirect_title_match",
 "title_unique_terms",
 "title_plain_min_raw_df",
 "redirect_title_plain_min_raw_ttf",
 "suggest_match",
 "title_stddev_raw_df",
 "category_plain_match",
 "category_plain_min_raw_df",
 "category_match",
 "title_match",
 "all_near_match",
 "all_plain_phrase_match",
 "heading_plain_match",
 "category_plain_mean_classic_idf",
 "all_phrase_match",
 "redirect_title_plain_min_raw_df",
 "auxiliary_text_plain_match",
 "text_plain_match",
 "heading_plain_min_raw_ttf",
 "opening_text_match",
 "opening_text_plain_match",
 "redirect_title_plain_match",
 "category_min_raw_ttf",
 "opening_text_mean_raw_df",
 "auxiliary_text_match",
 "title_unique_terms_diff_plain",
 "heading_dismax_plain",
 "all_phrase_match_dismax_plain",
 "title_dismax_plain",
 "opening_text_dismax_plain",
 "redirect_or_suggest_dismax",
 "category_dismax_plain",
 "auxiliary_text_dismax_plain",
 "redirect_title_dismax_plain",
 "text_dismax_plain",