There are two ways to look at Meb Keflezighi's chances of repeating as the Boston Marathon champion.
One year after two bombings claimed the lives of three spectators and injured more than 260 people, Keflezighi inspired a nation as he became the first American in 30 years to win the historic race. He enters the 2015 edition of the race as a favorite to defend his crown, and here's why the optimist would predict victory.
Not a strong overall field: Seeing Kenyan Patrick Makau's name on the start list might seem daunting at first. After all, he did run a world record 2 hours, 3 minutes, 38 seconds at the 2011 Berlin Marathon, but Makau's past few years have been plagued by injuries and setbacks. He won December's Fukuoka Marathon in 2:08:22, but that time is not out of range for Keflezighi's personal best on a good day in Boston.
The bigger threat would seem to be 2013 Boston champion Lelisa Desisa, who has had plenty of time to recover from his runner-up finishes at the New York City Marathon (2:11:06) in November and the Dubai Marathon (2:05:52) in January. Remember, though, that Desisa was a DNF in Boston last year and Keflezighi was quick to take advantage.
Looking at the international list and seeing seven runners under 2:05 is scary, but none of those times happened last year.
As for the Americans, the re-emergence of Dathan Ritzenhein could be the biggest challenge for Keflezighi. Ritzenhein was the top U.S. marathoner in 2012 and 2013 and holds a faster personal best, but injuries forced him to withdraw from Boston and any fall marathon plans in 2014. It has been 18 months since Ritzenhein raced a marathon.
Ritzenhein has looked strong in his cross-country races to open 2015, and if he's injury-free, then seeing him challenge Keflezighi could be fun. Keflezighi has owned Ritzenhein in their past three marathon faceoffs.
Better buildup: Much like 2014, Keflezighi has run two half-marathons before Boston this year. Last year's 61:23 to win the U.S. Half-Marathon Championships raised some eyebrows, and this year he went 62:18 to place fourth.
Keflezighi followed up that performance with a ninth-place finish in 62:17 at the 2014 NYC Half on March 15. He placed 10th in 62:53 at that race in 2014, and a 36-second improvement in his last race before Boston is a good sign.
Another factor to add is the solitude that Keflezighi enjoys starting a month away from Boston while training in Mammoth, California, where he gains focus.
WHY NO REPEAT?
Now that we know what's working in favor of Keflezighi, let's play devil's advocate and make a case against a repeat.
No more doubters: His best performances often come when no one expects them, but there are plenty of eyes on him this time around, and the additional attention and pressure could be a burden.
His win at the 2009 NYC Marathon was an inspired race as Keflezighi ran in memory of good friend and fellow marathoner Ryan Shay, who had died in 2007. The naysayers who saw the 2012 Olympics as his last go-round were proven wrong by his fourth-place finish. Last year, Keflezighi was discounted in Boston because of age, injuries and a bad performance in New York the previous autumn, but the memory of the 2013 bombings there pushed him to victory.
There are no such storylines this year, so will his motivation be the same?
Tactics he can't repeat: Keflezighi shared with ESPN The Magazine late last year how he won in Boston, watching defending champion Lelisa Desisa begin to falter by Mile 5 and then making a move to the lead at Mile 8. Keflezighi dropped a 4:30 split for his 16th mile and was off to the finish line by himself.
Keflezighi received help from the chase pack, where fellow Americans Ryan Hall and Nick Arciniaga did not push the pace and allowed the African runners to do their own work catching Keflezighi, something that helped build a large gap for him.
The Africans may have underestimated Keflezighi last year, but that won't happen this time. A new race strategy is in order.
History: No American has repeated at Boston since Bill Rodgers started his three-peat in 1978. Rodgers was also ranked the world's top marathoner by Track and Field News in 1975, 1977 and 1979, far from where Keflezighi stands now.
Competition clicking: Eritrea's Zersenay Tadese is the world-record holder in the half-marathon, but has not found his groove at the 26.2-mile distance. After two subpar marathons in London and not finishing at the 2013 Chicago Marathon, Tadese is switching things up and racing on a tactical course instead of a fast one, which could work to his benefit.
Kenyan Abel Kirui is similar to Keflezighi in that both have Olympic silver medals and fare well in championship-style races. Much like at the 2009 and 2011 world championships, where Kirui won gold medals, Boston does not have pacers for the race and that could play to his advantage.
Father Time: While Keflezighi has done a good job of outracing the clock, his age will always be an issue. He turns 40 on May 5, and the marathon world hasn't seen this kind of performance from an older runner since Haile Gebrselassie, at age 39, went 2:08:17 at the 2012 Tokyo Marathon.
Most recently, Kenyan Mark Kiptoo ran 2:06 in 2013 and 2014 at ages 37 and 38. Kiptoo has far less mileage on his legs, though, and is not competing at World Marathon Majors.
Add all this to often unpredictable weather conditions in Boston, and the intrigue around Keflezighi's repeat bid continues to build.