Boston, United States of America, Apr 15- Kenya's Geoffrey Kirui and Florence Kiplagat will seek to defend their titles when the Boston marathon goes down on Monday morning, celebrating its 122nd anniversary.
The four men who have won the past five Boston marathons -Kirui (2017), Lemi Berhanu (2016), Lelisa Desisa (2013 and 2015), and Meb Keflezighi (2014) - are all slated to start down route 135 in Hopkinton, giving a higher-than-usual chance that a two-time Boston winner will be crowned.
Boston was Kirui's breakthrough race in 2017, setting him up for victory at the IAAF World Championships London 2017 and making him the runner to beat this year, but not yet such an intimidating name that the others will cede him an inch.
In particular, Olympic bronze medallist and Chicago Marathon champion Galen Rupp, second only to Kirui here in 2017, is more likely to consider the Kenyan a problem to be solved rather than a barrier.
Berhanu will be making the trip from Hopkinton to Boston looking to recapture (and, hopefully, bottle) the lightning which struck him in 2016.
The Ethiopian's victory in 2016 punched his ticket for the Olympics, but after a victory in Xiamen early in 2017 he dropped out here and was fourth in New York.
Desisa returns to Boston after a year away, and though he is now three years removed from his last win here, he still holds an edge over the field's toughest member, the course itself.
The Ethiopian's familiarity with the rolling hills of the point-to-point route was such that even Berhanu might attribute his victory to it; it was Desisa who chose the time and place to break open the pack in 2016 and draw Berhanu away from his other rivals.
Among the returning champions, Keflezighi alone has conceded that at 43, his best years (including an Olympic silver medal in 2004 and a New York City Marathon win in 2009) may be behind him, but they're still too fresh for this to be a farewell tour.
If the door to victory is left ajar near Keflezghi, he won't hesitate to slip through it.
The four recent champions are far from the only ones worth mentioning. Olympic 10,000m bronze medallist Tamirat Tola, runner-up to Kirui last summer in London, has the fastest PB in the field at 2:04:11, but in Boston his silver medal from last year's World Championships is far more relevant than his PB.
Another point to recommend Tola is that his PB was run in Dubai; although Dubai and Boston couldn't be much more different, marathon runners who run fast in Dubai often also race well in Boston.
-Kiplagat faces tough opposition
There are few women in the past 10 years who have been as consistently successful in unpaced, championship-style marathons as 2017 Boston champion Edna Kiplagat, and there's no question that even at age 38 she will be the woman to beat on Monday.
The two-time world champion missed out on Olympic selection in 2016, but ended that year with a runner-up finish in Chicago.
She followed it with her victory in Boston in 2017 and then took the silver medal at the World Championships, just seven seconds behind the winner.
Aselefech Mergia's consistency is similar to Kiplagat's.
The Ethiopian has the fastest PB of the field, having clocked 2:19:31 during the second of her three Dubai Marathon wins. The 2010 London Marathon champion also has proven championship pedigree, having earned bronze at the 2009 World Championships.
But the domestic press is buzzing about the deepest field of US women in a single marathon since the 2016 Olympic team Trials, and possibly even long before that.
Shalane Flanagan leads that group after her commanding win last year in New York. After growing up in the Boston area, the 2008 Olympic 10,000m silver medallist has made winning in Boston a major goal of her career, although so far her best finish has been third.