This year's elite women's field for the Boston Marathon includes three former champions and two Americans who could challenge for the win.
Below is a look at the top contenders.
THE DEFENDING CHAMP
Rita Jeptoo (Kenya), 2:19:57 PR (Chicago, 2013)
Jeptoo took some people by surprise last year, despite the fact that she had also won Boston in 2006. But nobody should be shocked if the 33-year-old repeats this year. Since her Boston victory, she lowered her PR to 2:19:57 while winning Chicago in October. In February, she ran a 1:08 half-marathon, which wasn't as fast as her tuneup half last year, but still an indication she should be ready to race on Monday.
THE CHAMP'S TRAINING PARTNER
Jemima Sumgong (Kenya), 2:20:48 PR (Chicago, 2013)
In 2013, Sumgong made a big jump up the PR ladder, going from 2:28 to 2:23 with her victory last April in Rotterdam. She then joined the super-elite crowd by finishing second in 2:20:48 at Chicago behind her training partner Jeptoo. Sumgong knows the Boston course -- she was second in the heat in 2012, losing by just two seconds. She is reported to have been stronger than Jeptoo in training for this year's Boston. If absolutely forced to predict a winner, we'd go with Sumgong.
Mare Dibaba (Ethiopia), 2:19:52 PR (Dubai, 2012)
Dibaba is the fastest woman in the field based on PR. She started 2014 by winning the Xiamen Marathon in China in 2:21. That victory, the first in her marathon career, was important because Boston crowns go not only to those who can run fast, but who also can figure out how to win against deep fields. Note that both Ethiopian women and men have prevailed at Boston in April after winning marathons in January.
Shalane Flanagan (USA), 2:25:38 PR (Olympic Marathon Trials, 2012)
No American woman has won Boston since Lisa Larsen Weidenbach in 1985. Flanagan tried to change that last year and finished fourth in her first time on the Boston course. She returns not only wiser about the course, but also in great shape. In early March she ran a 47:03 to break the American record in a 15K. Look for Flanagan to run with the leaders as long as possible, and perhaps be more assertive after 30 kilometers than she was last year.
Sharon Cherop (Kenya), 2:22:28 PR (Berlin, 2013)
Cherop won Boston on a hot day in 2012, then placed third last year. She set her PR last September while finishing second in Berlin, so if she makes a move halfway through, her competitors will take it seriously.
Caroline Kilel (Kenya), 2:22:34 PR (Frankfurt, 2013)
Kilel's story is much like Cherop's: She's a former Boston champ (2011) who set her PR last fall. Despite a busy world-class career dating back to 2003, Kilel appears to still be on the upswing, and is dangerous in a sprint.