The IAAF World Championships start Saturday in Moscow, in what could be a season highlight for a sport racked by drugs, injuries, withdrawals and even the horrific incidents involving Oscar Pistorius and the Boston Marathon. In perhaps the darkest year the sport has seen, here are a few storylines that are worth watching next week:
Will Bolt keep bolting?
Track's chief superstar is still the headline name at the World Championships. Bolt will try to repeat the 100- and 200-meter double he produced at the last two Olympics. Bolt's competitors have dropped like flies; injured flies or artificially bulked-up flies. His chief rival in the 100, U.S. sprinter Tyson Gay, failed a doping test, as did veteran Jamaican Asafa Powell, leaving U.S. sprinter Justin Gatlin, the 2004 Olympic champ who already served his four-year doping suspension through 2010, to challenge Bolt.
In 2011, Bolt false-started and was disqualified in his chase for another world title at 100 meters. Countryman Yohan Blake, who won the title and later took silver at the Olympics, is down with hamstring injury. It's as if anyone who could push Bolt has been pushed out of the way.
That will leave some room open for Gatlin's teammates Mike Rodgers, the national champ in 2009, and TCU's Charles Silmon, to race onto the podium. Simon ran an impressive 9.94 earlier this year at the Texas Relays. Jamaica's Nesta Carter ran a 9.87 in Madrid this year, just off the 9.85 Bolt ran in London during his return to the Olympic city.
Without Gay in the 200, which may well be Bolt's better race, fellow Jamaican Warren Weir is the closest thing Bolt has to a challenger. Weir ran 19.79 earlier this season; Bolt's season best is 19.73. Weir's turns are strong, as are Bolt's. The U.S. team will sport Isiah Young, an Olympic semifinalist, and world newcomer Curtis Mitchell. Young, a recent Ole Miss grad, didn't even run track until his senior year of high school.
Bolt is the sport's singular and defining star, but as meaningful competition either becomes hurt or tainted, one has to ask how much he can really uplift a reeling sport.
Will we see a Felix fourpeat?
It won't be easy. Allyson Felix finally won her Olympic final last year after three gold medals and a bronze in the 200 at the world championships. But the Southern Californian is only two-for-four in 200s this season and she placed second to Kimberlyn Dixon at the U.S. Championships in June. What's more, Felix must outrun Jamaica's Shelly-Ann Fraser-Pryce, who finished second to Felix at the 200 in London and has twice won the Olympic 100. Fraser-Pryce has talked openly about putting greater emphasis this year on the 200, including the turns, and she won the Jamaican Nationals in 22.13 seconds, the fastest time in the world this season, making Felix's task look very tough, indeed.
Who will conquer the multis?
The world's greatest female athlete may actually be the last female athlete standing. Six of the top eight heptathletes from the London Games will not be in Moscow. Olympic champ Jessica Ennis-Hill of Great Britain is out with an Achilles tendon injury, and world champ Tatyana Chernova of Russia is out with both chronic elbow problems and a strained knee ligament she suffered while sprinting at the Russian championships this year. Only Antoinette Nana Dijmou of France, sixth in London, and Kristina Savitskaya, eighth in London, are returnees from the Olympics.
This should open the door for Sharon Day, the oft-injured 28-year-old Californian who comes from a family of high jumpers. Poland's Karolina Tyminska, fourth at the 2011 worlds, and Germany's Julia Machtig are also contenders.
The decathlon at worlds could be a U.S. affair even though both Olympic champ Ashton Eaton and world champ Trey Hardee had sub-par showings at Nationals. Eaton managed just 8,291 points, about 750 off of his world record, but has the individual scores this year to put together a championship effort if he can get through ten events. Hardee only completed three of ten at nationals, but he has a bye onto the worlds team as an additional U.S. competitor because of his world title in Daegu, South Korea in 2011. He also took the crown in Berlin in 2009.
A pair of Germans, Pascal Behrenbruch (8,514) and Michael Schrader (8,427), have the world's best results in 2013, though both will have to top those marks if the Yanks are at their best. Cuba's Leonel Suarez, a fixture on international podiums, is entered in the event but hasn't attempted a decathlon this season.
Do we smell home cooking?
This is a big 12 months for Russian sport, with the Olympics headed to Sochi in February. Russians fared well at the last championships, winning 19 medals, including nine golds, second to the U.S. team on both counts. The London numbers -- eight golds, 17 medals -- were similar.
Yuliya Zaripova, the 2011 champion in the 3,000-meter steeplechase, in the host's best chance to be a repeat winner. The Olympic and world champion has outclassed the field for the past two years. Mariya Savinova is a bit of a wildcard in the women's 800. The Olympic champ has run only twice all season, taking home easy victories but leaving open the question of her fitness for Moscow. Dmitri Tarabin recorded the world's best javelin mark since 2011 at the Russian championships last month. Pole vault legend Yelena Isinbayeva is back after clearing 4.75 meters to win the Russian nationals. Anna Chicerova, the gold medalist in 2011 and 2012, is the high jump favorite again; though Brigetta Barrett of the U.S. has the best jump in world (2.04 meters) this year. As always, look for any number of Russians to be strong in the race walks.
Can East African powerhouses go the distances?
An 800-meter race without Kenya's David Rudisha must be run with an asterisk. Rudisha suffered an injury to his right knee earlier this season, and despite six weeks of rehab in Germany, his coach, Colm O'Connell, insisted he stay home from Moscow. Ethiopia's Mohammed Amen is unbeaten in six races this year and the 19-year-old is emerging as a future Rudisha challenger.
Reigning world champ Asbel Kiprop of Kenya is unbeaten in international races at 1,500 this year, clocking 3:27.72 in Monaco, and should be the favorite in that race, even though his countryman Silas Kiplagat nipped him at the Kenyan trials.
Kenyans are masters of the steeplechase and Ezekiel Kemboi will have a shot at his sixth straight world medal. The two-time Olympic champ is also the two-time reigning world champ, after taking three straight world silver medals.
Kenya's Isiah Kiplangat might be the best candidate to challenge Britain's Mo Farah in the 5K, though Ethiopia's Dejen Gebremeskel and Imane Merga may be the strongest pair in the 10K.
Kenyans have won the men's marathon three times in a row and Ethiopians have only won it once -- in 2001 -- but Tsegay Kebede could end Ethiopia's slump. Kebede has won world and Olympic medals and is the London Marathon champ. His countryman Lelisa Desisa won the Dubai Marathon in January in 2:04:45, and he later won in Boston before tragedy struck there. The hotter the day, the better Desisa's chances.
For the women, Kenya's Janeth Jepkosgei is always a threat to win the 800, with one medal of each color from the last three world championships. Native Ethiopian Abeba Aregawi has been the world's best at 1,500 this season, though unfortunately for the Ethiopians, she now runs for Sweden, leaving that race wide open. Kenya's Faith Kipyegon and Hellen Obiri are in the mix with Ethiopia's Genzebe Dibaba, but two U.S. runners, 17-year-old Mary Cain and reigning surprise champ Jenny Simpson make this a very compelling distance race for the States.
Ethiopians Meseret Defar and Tirunesh Dibaba have been chasing each other for the better part of a decade and could do it again in both the 5,000 and 10,000 in Moscow.
Both the defending world and Olympic marathon champions have something to prove in Moscow. Kenya's Edna Kiplagat crossed the line first in Daegu but then stumbled into 20th place in London. Ethiopia's Tiki Gelana won gold in London, but then suffered a mishap on those same streets this year when she collided with a wheelchair racer during the London Marathon and ended in 16th place. Both ladies return to Moscow looking for another title.
Look for the Kenyan men to be stronger. Look for the Ethiopian women to be stronger.