This year, sport has been rocked by a string of incredible happenings across all sports.
The Rundown has picked out the biggest seven stories among the multitude of scandals, surprises, outrages, revelations and horrors that we've seen in 2013, and will be counting them down between Christmas and New Year.
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Shocks of the Year #2: The Boston Marathon Bombing
On April 15 a terror attack on one of the world’s biggest marathons sent shockwaves throughout the world.
It was arguably the biggest terrorist atrocity to hit sport in the West since the 1972 Munich Olympics, when 11 Israeli athletes and a German policeman were murdered by Palestinian militants.
Nearly two hours after the elite athletes had completed the Boston Marathon, Chechen brothers and US residents Tamerlan and Dzhkokhar Tsarnaev detonated home-made pressure-cooker bombs at the finish line, in an attempt to inflict maximum damage both to spectators and runners.
Three were killed and hundreds were maimed, some with life-changing injuries, while many more were left mentally scarred by the cowardly attack.
The incident shocked the world, let alone the United States. With athletes from across the globe competing, and many spectators merely visitors or foreign students in one of the world’s great university cities, it was seen as an attack on civilisation, as well as the American people.
Amidst the horror and the analysis, the bravery of emergency services and ordinary members of the public helped unite a city and a nation. And with the world on lookout, the two suspects were quickly identified, with the car-jacking, man-hunt and shoot-out captivating the world.
Eventually they were apprehended, with the elder brother Tamerlan killed and college student Dzhokhar captured after being found hiding in a boat. A university police officer was also killed in the gunfire, which was beamed across the globe on television and internet streams.
There was much hand-wringing about how two intelligent, attractive and edcuated young men could be drawn to the radical strain of Islam that apparently inspired their terror attack.
The elder brother was a talented boxer but an angry social outcast who had apparently turned to religion.
The younger brother, Dzhkokhar, was very different. He did not display the markers of a terrorist; he was popular, laid-back and apparently non-violent - attributes which made his participation in one of the worst ever atrocities committed at a sporting event all the more shocking and baffling. He remains in custody awaiting trial as prosecutors decide whether to pursue the death penalty, with a decision expected in the New Year.