Bennet Omalu is a physician specialized as a forensic expert and pathologist, which means he examines the tissues and organs of dead people to determine their cause of death. One day, he was asked to prepare an autopsy report about the corpse of a 50-year-old man named Mike Webster, a former professional US football player. Having examined the corpse in detail, the physician reported his cause of death to be "heart attack." While examining the brain structure during the autopsy, he noticed a pathology normally seen in the brains of boxers, and decided to study this player's life. Mike Webster had been an American football player since his childhood and had been a professional player for 18 years. Dr. Omalu watched this player's games and noticed that Webster often played in the most dangerous positions where collisions with rival players were the highest, and he had sustained very serious blows to his head. Taking into consideration the number of the games he participated in, Omalu calculated that this player had sustained more than 70,000 blows to his head. Realizing that Webster suffered from short-term blackouts after collisions as well, Omalu concentrated his studies on his brain.