whiz. and decided to use his math skill his in casinos. >> he started going to atlantic city. and card counting. and he did it until they kicked him out. it was a challenge. it was not for the money. it was the idea of being able to use your mind to create profitably. >> eventually, john would become a trader at the philadelphia stock exchange and work with and mentor pete delici. >> john did everything to an extreme. so if he believed in something or he felt that mathematically he had an edge, he would exploit that as big as he could. >> part of john's strategy was to have competitors on the trading floor underestimate him. >> he wore scrubs on the floor because he wanted people to think he was you know, a goof ball and didn't know what he was doing. >> but john did know what he was doing and became a