OK, I think I understand what happened. In the "alltime" list, many of the 10km road times, marked with a "+", were not 10km road races, but achieved "en route" in longer races, e.g. a semi-marathon. This explains most of the difference, but when she ran 30:37 in Oct. 2013, looking strictly at 10km races, before Oct. 2013, she was still only 6th fastest woman. Upon closer inspection, this "fifth fastest woman ever" at Wikipedia was written in April 2012, by "Sillyfolkboy" when he created the athlete bio, and refers to her 30:38 performance in Tilburg (NED) in Sep. 2011, a result found at the IAAF website, but not appearing in the alltime list. This time made her 5th fastest woman of all time. I think Wikipedia accuracy is a community effort. Neither Chepkirui, nor her coach, nor her agent, nor anyone really, is under any obligation to update a Wikipedia entry (in English). As I mentioned, this "fifth fastest woman ever" was penned in 2012, and has never been updated since. By my quick count, she has now dropped to "fifteenth fastest woman ever" in a 10km road race. The number of times that the 10km road top times occurred in a longer race (I counted 12 out of the top 30) suggests that these top times for 10km road could be much faster if more attempts were made at that specific distance.