Kolkata: Country's first professional full-time football coach and former India player Amal Dutta died at a city hospital on Sunday following old age complications, his family said. The 86-year-old, who as coach had introduced new formations including the exciting diamond system to enthrall the spectators in the 1990s, left behind his wife, a son and a daughter. "He was suffering from breathing problems, but was well till the morning. His condition deteriorated in the evening when we rushed him to a hospital. The doctors tried a lot but could not help," said his son Ashis Dutta. A midfielder during his playing days, Dutta represented India in the 1954 Asian Games at Manila. Post his playing career, he went to England for a one-year FA coaching course, where he was taught by the renowned Walter Winterbottom. On returning to India his first major assignment was to coach the Railways in 1960 for the Santosh Trophy. In a country where most sportspersons then aimed at landing a government job for Abringing stability in their lives, Dutta swam against the current and quit as a railway employee out of his love for soccer and to pursue a full-time professional coaching career. He is hailed as the country's first professional soccer coach, and credited for shaping Indian football. Dutta's first assignment with a big club was in 1963 with East Bengal, and from the outset he showed great tactical planning, and a daring to opt for new systems. On July 13, 1997, a record 1.31 lakh plus spectators gathered at the Salt Lake stadium here to witness a derby game between Amal Dutta coached Mohun Bagan and East Bengal. It was the Federation Cup semi-final, and soccer aficionados expectations had sky-rocketed with Dutta introducing the Diamond system (4-1-2-1-2 formation) first time in Indian football. Though Mohun Bagan went down 1-4, the way they played throughout the tournament gave much joy to the fans. "This system was needed. Spectators come to the ground hoping to watch good football, full of excitement and speed. And this system gave them all that,"Dutta would later say. Besides city giants East Bengal and Mohun Bagan, he also coached the Indian national team. He served as the technical director of the Indian team in the 1987 Nehru Gold Cup. Dutta also had a coaching stint in Odisha (then called Orissa). Dutta, a poet and table player, also earned much plaudits for penning serialised pieces in a Bengali magazine decades back on the tactics, gameplan and strategies involved in football. In 1996, Dutta adventured into politics and contested the Lok Sabha election from the earstwhile Calcutta North West constituency on the BJP ticket but finished third. Former players and coaches payed rich tributes to him. "I did not have the fortune to play under him but have heard a lot about him. His thought process was far ahead of his time," said former India captain Baichung Bhutia. Former India defender Subrata Bhattacharya said: "He played a big role in shaping India's football and he created numerous talents. His contribution to football is invaluable. His deserved many awards for his sheer contribution to the game." Mohun Bagan head coach Sanjoy Sen said: "His death is an irreparable loss to football. His acumen for the game was unmatched. He shall forever be remembered for his diamond system formation."