The women's race at the 2018 IAAF World Half Marathon Championship in Valencia, Spain this weekend will be headlined by Joyciline Jepkosgei of Kenya, who broke the world record twice last year. 

The Kenyans lost their likely No. 2 and No. 3 in Fancy Chemutai, the second-fastest woman in world history, and Mary Wacera, a two-time World Half medalist, in a late withdrawal announced on Wednesday afternoon by the Kenyan newspaper Daily Nation.

On Thursday, the IAAF preview indicated that Jordan Hasay has also withdrawn from the race. USATF has not yet responded for comment.

Original article below.

FloTrack subscribers in Canada can watch the IAAF World Half Marathon Championships this Saturday HERE!

World Record Holder Jepkosgei (64:51 PB) vs. No. 2 All-Time Chemutai (64:52 PB)

The 24-year-old Jepkosgei twice broke the world record last year, as she clocked 64:52 to win the Prague Half Marathon in April, then lowered her standard by exactly one second in running 64:51 to win the Valencia Half Marathon in October.

Despite Jepkosgei's credentials as the world record holder, it's her countrywoman Chemutai, whose 23rd birthday was yesterday, who should be favored for the victory after running 64:52—one excruciating second off Jepkosgei's WR!—to win the RAK Half Marathon in the United Arab Emirates last month.

That race was billed as a matchup between Jepkosgei and 2:17 marathoner Mary Keitany, but the world record holder was reportedly off her game due to the flu and ended up fifth in 66:46, nearly two minutes behind Chemutai and Keitany. 

Chemutai held road racing legend Keitany off by three seconds to establish herself as a favorite heading into these championships, though it should be noted she sustained a minor ankle injury during the race which cost her some training time.

My victory in @rakmarathon! With an ankle problem in my preparation I have lost some important training days, but so extremely proud I made it this far. Thanks to my management @VolareSports and sponsor @adidasrunning for the support! #teamVolare #teamAdidas pic.twitter.com/2gvYgSDfSt

— Fancy Chemutai (@FancyChemutai_) February 9, 2018

It's amazing how things can change in a year's time. 

Chemutai was in both of Jepkosgei's world record races last year, but nowhere close to her rival. She was third in Prague, 2:06 behind Jepkosgei, and second in Valencia, 45 seconds behind. Before that? Her only listed result from 2016 is a 32:21 runner-up finish in the Kericho 10K in Kenya.

A year ago, Jepkosgei wasn't even the world record holder yet. 

Another Kenyan, Peres Jepchirchir, ran 65:06 last February to improve the record of 65:09 set by yet another Kenyan, Florence Kiplagat, in 2015.

Jepchirchir is actually the defending IAAF world half marathon champion but has not raced since her record run and will not race this weekend as she is currently on maternity leave from the sport.

So How Fast Can They Run?

It's interesting to note that while Jepkosgei set the half marathon world record in Valencia, her en-route world records of 45:37 for 15K and 61:25 for 20K still stand from her first record run in Prague.

(She also set an en-route 10K road record of 30:40 in her Prague half marathon, which she smashed with a time of 29:43 in an outright 10K in Prague last fall).

Watch Jepkosgei's world record run in Prague:

Unlock this video, live events, and more with a subscription!

Sign Up

Already a subscriber? Log In

The opening paces for both world records were similar: 14:53 for 5K and 30:04 for 10K in Prague; 14:52 for 5K, and 30:09 for 10K in Valencia.

Shortly after the 10K mark, however, the wheels fell off her prior pacing--she reached the 15K mark in Valencia in 45:59 (22 seconds off her Prague pace) and the 20K mark in 61:30 (five seconds off her Prague pace) before charging to a record by one second. 

The women may start things more conservatively this time--a 64:50 would require 1K splits of 3:04.38, or mile splits of 4:56.73--which would put them at 15:21 through 5K, 30:43 through 10K, 46:05 through 15K and 61:27 through 20K. 

It's unclear how much of an effect Chemutai's minor injury has affected her training and race plan.

Honestly, Just Give The Trophy To Kenya

You have to run the race for a reason, but there's also a reason why every woman's name I've mentioned so far in conjunction with the half marathon world record represents Kenya. 

The top three runners for each nation count in scoring for the team title tabulation. 

Kenya's No. 3?

Mercy Wacera, who earned bronze and silver in the past two editions of the IAAF world half marathon championships. She has the experience and the hardware to perhaps even sneak away with a win, if her countrywomen falter from a too-hot early pace. She recently ran 66:50, the second-fastest time of her career, for third place at the Houston Half Marathon. 

No. 4 for Kenya is Ruth Chepngetich, who won four straight half marathons in Europe last year, including a 66:19 PB in Istanbul.

The Challengers

The biggest dark horse in this race is probably Ruti Aga of Ethiopia, who put it to Wacera at the Houston Half Marathon by 11 seconds for a 66:39 win.

The 24-year-old was most recently second at the Tokyo Marathon in 2:21:19. She was also runner-up at the Berlin Marathon last fall.

There's also Eunice Chumba of Bahrain, who was sixth at the Houston Half Marathon. She ran a PB of 66:11 last fall, though she was just 11th at the RAK Half Marathon.

American Record Watch For Jordan Hasay

Another top entrant is the future of American marathon running, Jordan Hasay, whose run here is her last tune-up before tackling her ultimate goal: winning the Boston Marathon. 

The 26-year-old was eighth at the Houston Half Marathon in 68:38, well behind the likes of Aga and Wacera, and 1:13 behind Molly Huddle, whose mark of 67:25 set a new American record.

Hasay ran her PB of 67:55 in Prague last year, her final tune-up before taking third in Boston, so this race will be a fun barometer to measure her chances for a win in Beantown this year. 

And though she'd have to cut a good 30 seconds off her best time, it's not completely out of the question for Hasay to challenge Huddle's time in Spain.

We talked to Jordan Hasay after her eighth-place finish at the Houston Half Marathon: