The depth in Valencia is ridiculous: 25 men under 2:08, 35 under 2:10, 44 under 2:12. Plus there are some real studs running, from 2:02 man Birhanu Legese and Boston/Chicago champ Lawrence Cherono to NYC champ Joyciline Jepkosgei and World Half champ Peres Jepchirchir. *MB: Are you ready for the DEEPEST marathon EVER? Sunday's Valencia Marathon is laughably good.

Two-time BAA 10k champ Stephen Sambu and Daniel Chebii face Geoffrey Koech (27:18), 58:42 half runner Stephen Kiprop, and Abdi Abdirahman. Aliphine Tuliamuk, former Boston champ Caroline Rotich, Betsy Saina and 30:06 woman Fancy Chemutai lead the women's race.

Houston is always one of the highlights of the winter for US fans and this year's races could be extra special as Olympic silver medallist Sally Kipyego races for the 1st time since declaring she'll represent the US moving forward and Kara Goucher races a marathon for the 1st time as a 40-year old. The problem is the weather forecast doesn't look good but what does look good is the international fields in both the men's and women's halves as they are loaded with talent.

Kipruto now sits second on the all-time list, only behind Leonard Patrick Komon's 26:44. Caroline Kipkirui ran the #5 all-time best 10k to win the women's race in 30:19 ahead of Fancy Chemutai (30:22) and Diana Chemtai Kipyokei (30:23).

The two fastest women in history are expected to put on a terrific battle for gold. Behind them, could Jordan Hasay break the American record or sneak a medal?

Are you ready for some incredible, free prime-time half-marathon action? We hope as as Thurday's night RAK Half is going to be insane. Watch it live on LetsRun at 9:45 pm ET.

Other big names include Vivian Cheruiyot, 2014 World Half champ Gladys Cherono and Fancy Chemutai who ran 65:36 to finish runner-up with Jepkosgei set her WR.

2017 has been a revolutionary one for women in the half marathon. We look at that, Fancy Chemutai and Sondre Moen, and a premature celebration and runners going off course.