Halfway through the tournament, the scrappy underdogs of Team USA had two gold medals. >> But the Russian march to first place continued. >> We are this great rival for everybody.>> Peter Zukov is a Russian businessman and the founder of the Russian Chess Boxing Federation. >> He told us chess and boxing are hardwired into Russia's history. In Soviet old school Russian boxing gyms, they would play chess after boxing training.They would just do it to develop certain qualities in their fighters. >> They play ...

Fighters from 18 countries are here trying to knock each other's heads off. There's the bell. But wait, now the fighters strip off their gloves and play chess. This is chess boxing. >> Chess is battle on a board. And boxing is chess with my body. So when someone combined those two, I was like, "Yes, here's what I was made for. ...